RESUMEN

Nitric oxide (NO) acts in different physiological processes, such as blood pressure control, antiparasitic activities, neurotransmission, and antitumor action. Among the exogenous NO donors, ruthenium nitrosyl/nitro complexes are potential candidates for prodrugs, due to their physicochemical properties, such as thermal and physiological pH stability. In this work, we proposed the synthesis and physical characterization of the new nitro terpyridine ruthenium (II) complexes of the type [RuII(L)(NO2)(tpy)]PF6 where tpy = 2,2':6',2″-terpyridine; L = 3,4-diaminobenzoic acid (bdq) or o-phenylenediamine (bd) and evaluation of influence of diimine bidentate ligand NH.NHq-R (R = H or COOH) in the HSA/DNA interaction as well as antiviral activity. The interactions between HSA and new nitro complexes [RuII(L)(NO2)(tpy)]+ were evaluated. The Ka values for the HSA-[RuII(bdq)(NO2)(tpy)]+ is 10 times bigger than HSA-[RuII(bd)(NO2)(tpy)]+. The sites of interaction between HSA and the complexes via synchronous fluorescence suppression indicate that the [RuII(bdq)(NO2)(tpy)]+ is found close to the Trp-241 residue, while the [RuII(bd)(NO2)(tpy)]+ complex is close to Tyr residues. The interaction with fish sperm fs-DNA using direct spectrophotometric titration (Kb) and ethidium bromide replacement (KSV and Kapp) showed weak interaction in the system fs-DNA-[RuII(bdq)(NO)(tpy)]+. Furthermore, fs-DNA-[RuII(bd)(NO2)(tpy)]+ and fs-DNA-[RuII(bd)(NO)(tpy)]3+ system showed higher intercalation constant. Circular dichroism spectra for fs-DNA-[RuII(bd)(NO2)(tpy)]+ and fs-DNA-[RuII(bd)(NO)(tpy)]3+, suggest semi-intercalative accompanied by major groove binding interaction modes. The [RuII(bd)(NO2)(tpy)]+ and [RuII(bd)(NO)(tpy)]3+ inhibit replication of Zika and Chikungunya viruses based in the nitric oxide release under S-nitrosylation reaction with cysteine viral.

Asunto(s)

Antivirales , ADN , Rutenio , Humanos , ADN/metabolismo , ADN/química , Rutenio/química , Rutenio/farmacología , Antivirales/farmacología , Antivirales/química , Antivirales/metabolismo , Ligandos , Animales , Albúmina Sérica Humana/química , Albúmina Sérica Humana/metabolismo , Piridinas/química , Piridinas/farmacología , Iminas/química , Iminas/farmacología , Complejos de Coordinación/farmacología , Complejos de Coordinación/química , Complejos de Coordinación/metabolismo

RESUMEN

The development of coordination compounds with antineoplastic therapeutic properties is currently focused on non-covalent interactions with deoxyribonucleic acid (DNA). Additionally, the interaction profiles of these compounds with globular plasma proteins, particularly serum albumin, warrant thorough evaluation. In this study, we report on the interactions between biomolecules and complexes featuring hydrazone-type imine ligands coordinated with vanadium. The potential to enhance the therapeutic efficiency of these compounds through mitochondrial targeting is explored. This targeting is facilitated by the derivatization of ligands with triphenylphosphonium groups. Thus, this work presents the synthesis, characterization, interactions, and cytotoxicity of dioxidovanadium(V) complexes (C1-C5) with a triphenylphosphonium moiety. These VV-species are coordinated to hydrazone-type iminic ligands derived from (3-formyl-4-hydroxybenzyl)triphenylphosphonium chloride ([AH]Cl) and aromatic hydrazides ([H2L1]Cl-[H2L5]Cl). The structures of the five complexes were elucidated through single-crystal X-ray diffraction and vibrational spectroscopies, confirming the presence of dioxidovanadium(V) species in various geometries with degrees of distortion (τ = 0.03-0.50) and highlighting their zwitterionic characteristics. The molecular structural stability of C1-C5 in solution was ascertained using 1H, 19F, 31P, and 51V-nuclear magnetic resonance. Moreover, their interactions with biomolecules were evaluated using diverse spectroscopic methodologies and molecular docking, indicating moderate interactions (Kb ≈ 104 M-1) with calf thymus DNA in the minor groove and with human serum albumin, predominantly in the superficial IB subdomain. Lastly, the cytotoxic potentials of these complexes were assessed in keratinocytes of the HaCaT lineage, revealing that C1-C5 induce a reduction in metabolic activity and cell viability through apoptotic pathways.

Asunto(s)

Antineoplásicos , Complejos de Coordinación , ADN , Compuestos Organofosforados , Vanadio , Humanos , Vanadio/química , Vanadio/farmacología , Complejos de Coordinación/farmacología , Complejos de Coordinación/química , Complejos de Coordinación/síntesis química , Antineoplásicos/farmacología , Antineoplásicos/química , Antineoplásicos/síntesis química , Compuestos Organofosforados/química , Compuestos Organofosforados/farmacología , ADN/metabolismo , ADN/química , Supervivencia Celular/efectos de los fármacos , Hidrazinas/química , Hidrazinas/farmacología , Animales , Simulación del Acoplamiento Molecular , Albúmina Sérica Humana/química , Albúmina Sérica Humana/metabolismo , Estructura Molecular , Ligandos , Línea Celular Tumoral , Ensayos de Selección de Medicamentos Antitumorales

RESUMEN

This study characterized four corrole derivatives, namely Cbz-Cor, MetCbz-Cor, PTz-Cor, and PTzEt-Cor, examining their photophysical, electrochemical, photobiological, and biomolecule-binding properties. Experimental photophysical data of absorption and emission elements correlated with a theoretical analysis obtained through time-dependent density functional theory (TD-DFT). As for the photophysical properties, we observed lower fluorescence quantum yields and discernible differences between the excited and ground states, as indicated by Stokes shift values. Natural Transition Orbit (NTO) plots presented high occupied molecular orbital - low unoccupied molecular orbital (HOMO-LUMO) densities around the tetrapyrrolic macrocycle in all examples. Our findings demonstrate that corroles maintain stability in solution and offer photostability (<20 %), predominantly in DMSO(5 %)/Tris-HCl (pH 7.4) buffer solution. Furthermore, the singlet oxygen (1O2) quantum yield and log POW values underscore their potential application in photoinactivation approaches, as these corroles serve as effective ROS generators with more lipophilic features. We also evaluated their biomolecular binding capacity towards salmon sperm DNA and human serum albumin using spectroscopic techniques and molecular docking analysis for sustenance. Concerning biomolecule interaction profiles, the corrole derivatives showed a propensity for interacting in the minor grooves of the double helix DNA due to secondary forces, which were more pronounced in site III of the human serum protein.

Asunto(s)

Carbazoles , ADN , Fenotiazinas , Albúmina Sérica Humana , ADN/química , Fenotiazinas/química , Humanos , Carbazoles/química , Albúmina Sérica Humana/química , Albúmina Sérica Humana/metabolismo , Porfirinas/química , Animales , Unión Proteica , Salmón , Simulación del Acoplamiento Molecular , Oxígeno Singlete/química , Oxígeno Singlete/metabolismo

RESUMEN

Human serum albumin (HSA) is the most prominent protein in blood plasma, responsible for the maintenance of blood viscosity and transport of endogenous and exogenous molecules. Fatty acids (FA) are the most common ligands of HSA and their binding can modify the protein's structure. The protein can assume two well-defined conformations, referred to as 'Neutral' and 'Basic'. The Neutral (N) state occurs at pH close to 7.0 and in the absence of bound FA. The Basic (B) state occurs at pH higher than 8.0 or when the protein is bound to long-chain FA. HSA's allosteric behaviour is dependent on the number on FA bound to the structure. However, the mechanism of this allosteric regulation is not clear. To understand how albumin changes its conformation, we compared a series of HSA structures deposited in the protein data bank to identify the minimum amount of FA bound to albumin, which is enough to drive the allosteric transition. Thereafter, non-biased molecular dynamics (MD) simulations were used to track protein's dynamics. Surprisingly, running an ensemble of relatively short MD simulations, we observed rapid transition from the B to the N state. These simulations revealed differences in the mobilities of the protein's subdomains, with one domain unable to fully complete its transition. To track the transition dynamics in full, we used these results to choose good geometrical collective variables for running metadynamics simulations. The metadynamics calculations showed that there was a low energy barrier for the transition from the B to the N state, while a higher energy barrier was observed for the N to the B transition. These calculations also offered valuable insights into the transition process.

Asunto(s)

Albúmina Sérica Humana , Albúmina Sérica , Humanos , Albúmina Sérica Humana/metabolismo , Unión Proteica , Albúmina Sérica/química , Albúmina Sérica/metabolismo , Ácidos Grasos/química , Termodinámica , Sitios de Unión

RESUMEN

To explore in vivo application of quantum dots (QDs), it is essential to understand the dynamics and energetics of interactions between QDs and proteins. Here, surface plasmon resonance (SPR) and molecular docking were employed to investigate the kinetics and thermodynamics of interactions between human serum albumin (HSA) and CdTe QDs (~3 nm) functionalized with mercaptopropionic acid (MPA) or thioglycolic acid (TGA). Kinetic analysis showed that HSA-QD interactions involved transition-complex formation. Despite the structural similarities between MPA and TGA, the [HSA-CdTe@TGA]‡ formation by association of free HSA and QDs demanded 70% more energy and higher entropic gain (Ea-TGA‡= 65.10 and T∆Sa-TGA‡= 28.62 kJ mol-1) than the formation of [HSA-CdTe@MPA]‡ (Ea-MPA‡ = 38.13 and T∆Sa-MPA‡ = 0.53kJ mol-1). While the [HSA-CdTe@MPA]° dissociation required higher energy and lower entropy loss (Ed-MPA‡ = 49.96 and T∆Sd-MPA‡ = - 32.18kJ mol-1) than the [HSA-CdTe@TGA]° dissociation (Ed-TGA‡= 30.78 and T∆Sd-TGA‡= - 51.12 kJ mol-1). The stability of [HSA-QDs]° was independent of the temperature and functionalizing group. However, the enthalpic and entropic components were highly affected by the substitution of MPA (ΔH° = - 11.83 and TΔS° = 32.72 kJ mol-1) with TGA (ΔH° = 34.31 and TΔS° = 79.73 kJ mol-1). Furthermore, molecular docking results indicated that the metal site on the QDs contributes to the stabilization of [HSA-QDs]°. Therefore, differences in QD functionalization and surface coverage densities can alter the HSA-QD interaction, thus their application.

Asunto(s)

Compuestos de Cadmio/farmacología , Albúmina Sérica Humana/metabolismo , Compuestos de Sulfhidrilo/química , Telurio/farmacología , Tioglicolatos/química , Compuestos de Cadmio/química , Entropía , Humanos , Cinética , Simulación del Acoplamiento Molecular , Puntos Cuánticos , Albúmina Sérica Humana/química , Resonancia por Plasmón de Superficie , Telurio/química , Termodinámica

RESUMEN

The interaction between two nitrosyl ruthenium complexes [Ru (NH.NHq-COOH)(tpy)NO](PF6 )3 (RuBDQ) and [Ru (NH.NHq-H)(tpy)NO](PF6 )3 (RuBD) and human serum albumin (HSA) was investigated using spectroscopic and computational methods. From fluorescence experiments, a dynamic quenching mechanism and binding constants at a single site demonstrated the higher stability of the RuBDQ-HSA system at 308 K compared with RuBD-HSA. Thermodynamic parameters indicated that binding of RuBDQ and RuBD to HSA was mainly driven by hydrophobic interaction and hydrogen bonding, respectively. Synchronous fluorescence and FT-IR results suggested that interactions between both nitrosyl ruthenium complexes and HSA affected protein conformation. Competition experiments revealed that RuBDQ and RuBD bound to Sudlow sites I and II, respectively. Molecular docking results showed that RuBDQ interacted with Ser-192 and Ala-291 residues via hydrogen bonding and polar contact, respectively, whereas RuBD associated with Asn-391 via a polar interaction. Noncovalent interaction results suggested that van der Waals interactions were the main binding forces for both systems, i.e. RuBDQ associated with Trp-214 via van der Waals interaction and with Ty-150 via dipole-dipole bonding, whereas RuBD associated with Tyr-452 via van der Waals forces. The Asp-391 residue interacted with the nitrosyl ligand via polar contact and the terpyridine ligand via van der Waals interaction.

Asunto(s)

Rutenio , Sitios de Unión , Dicroismo Circular , Humanos , Simulación del Acoplamiento Molecular , Unión Proteica , Albúmina Sérica Humana/metabolismo , Espectrometría de Fluorescencia , Espectroscopía Infrarroja por Transformada de Fourier , Termodinámica

RESUMEN

The simultaneous determination of adhesion and deformability parameters of erythrocytes was carried out through a microfluidic device, which uses an inverted optical microscope with new image acquisition and analysis technologies. Also, an update of the models describing erythrocyte adhesion and deformation was proposed. Measurements were carried out with red blood cells suspended in saline solution with human serum albumin at different concentrations. Erythrocytes adhered to a glass surface were subjected to different low shear stress (from 0.04 to 0.25 Pa), causing cellular deformation and dissociation. The maximum value obtained of the erythrocyte deformability index was 0.3, and that of the adhesion energy per unit area was 1.1 × 10-6 Pa m, both according to previous works. The obtained images of RBCs adhered to glass reveal that the adhesion is stronger in a single point of the cell, suggesting a ligand migration that concentrates the adhesion in a "spike-like tip" in the cell. Moreover, adhesion energy results indicate that the energy required to separate erythrocytes in media with a lower albumin concentration is greater. Both results could be explained by the mobility of membrane receptors.

Asunto(s)

Deformación Eritrocítica , Eritrocitos/citología , Microfluídica , Adulto , Adhesión Celular , Vidrio , Humanos , Procesamiento de Imagen Asistido por Computador , Dispositivos Laboratorio en un Chip , Ligandos , Membrana Dobles de Lípidos , Presión , Albúmina Sérica Humana/metabolismo , Resistencia al Corte , Estrés Mecánico , Viscosidad , Adulto Joven

RESUMEN

We addressed the involvement of the receptor for advanced glycation end products (RAGE) in the impairment of the cellular cholesterol efflux elicited by glycated albumin. Albumin was isolated from type 1 (DM1) and type 2 (DM2) diabetes mellitus (HbA1c > 9%) and non-DM subjects (C). Moreover, albumin was glycated in vitro (AGE-albumin). Macrophages from Ager null and wild-type (WT) mice, or THP-1 transfected with siRNA-AGER, were treated with C, DM1, DM2, non-glycated or AGE-albumin. The cholesterol efflux was reduced in WT cells exposed to DM1 or DM2 albumin as compared to C, and the intracellular lipid content was increased. These events were not observed in Ager null cells, in which the cholesterol efflux and lipid staining were, respectively, higher and lower when compared to WT cells. In WT, Ager, Nox4 and Nfkb1, mRNA increased and Scd1 and Abcg1 diminished after treatment with DM1 and DM2 albumin. In Ager null cells treated with DM-albumin, Nox4, Scd1 and Nfkb1 were reduced and Jak2 and Abcg1 increased. In AGER-silenced THP-1, NOX4 and SCD1 mRNA were reduced and JAK2 and ABCG1 were increased even after treatment with AGE or DM-albumin. RAGE mediates the deleterious effects of AGE-albumin in macrophage cholesterol efflux.

Asunto(s)

HDL-Colesterol/sangre , LDL-Colesterol/sangre , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Macrófagos/metabolismo , Receptor para Productos Finales de Glicación Avanzada/genética , Adulto , Animales , Estudios de Casos y Controles , Línea Celular , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/patología , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/patología , Femenino , Fibroblastos/citología , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo , Regulación de la Expresión Génica , Hemoglobina Glucada/genética , Hemoglobina Glucada/metabolismo , Productos Finales de Glicación Avanzada/sangre , Productos Finales de Glicación Avanzada/farmacología , Humanos , Janus Quinasa 2/genética , Janus Quinasa 2/metabolismo , Macrófagos/efectos de los fármacos , Macrófagos/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , NADPH Oxidasa 4/genética , NADPH Oxidasa 4/metabolismo , Subunidad p50 de NF-kappa B/genética , Subunidad p50 de NF-kappa B/metabolismo , ARN Interferente Pequeño/genética , ARN Interferente Pequeño/metabolismo , Receptor para Productos Finales de Glicación Avanzada/antagonistas & inhibidores , Receptor para Productos Finales de Glicación Avanzada/deficiencia , Receptor para Productos Finales de Glicación Avanzada/metabolismo , Albúmina Sérica Humana/metabolismo , Albúmina Sérica Humana/farmacología , Células THP-1 , Triglicéridos/sangre

RESUMEN

In this study, half-sandwich Ru(II) complexes containing acylthiourea ligands of the general type [Ru(η6-p-cymene)(PPh3)(S)Cl]PF6 (1m-6m) and [Ru(η6-p-cymene)(PPh3)(S-O)]PF6 (1b-6b) where S/S-O = N',N'-disubstituted acylthiourea were synthesized and characterized (via elemental analyses, IR spectroscopy, 1H NMR spectroscopy, 13C{1H} NMR spectroscopy, and X-ray diffractometry), and their cytotoxic activity was evaluated. The different coordination modes of the acylthiourea ligands, monodentately via S (1m-6m) and bidentately via S,O (1b-6b), to ruthenium were modulated from different synthetic routes. The cytotoxicity of the complexes was evaluated in five human cell lines (DU-145, A549, MDA-MB-231, MRC-5, and MCF-10A) by MTT assay. The IC50 values for prostate cancer cells (2.89-7.47 µM) indicated that the complexes inhibited cell growth, but that they were less cytotoxic than cisplatin (2.00 µM). Unlike for breast cancer cells (IC50 = 0.28-0.74 µM) and lung cancer cells (IC50 = 0.51-1.83 µM), the complexes were notably more active than the reference drug, and a remarkable selectivity index (SI 4.66-19.34) was observed for breast cancer cells. Based on both the activity and selectivity, complexes 5b and 6b, as well as their respective analogous complexes in the monodentate coordination 5m and 6m, were chosen for further investigation in the MDA-MB-231 cell line. These complexes not only induced morphology changes but also were able to inhibit colony formation and migration. In addition, the complexes promoted cell cycle arrest at the sub-G1 phase inducing apoptosis. Interaction studies by viscosity measurements, gel electrophoresis, and fluorescence spectroscopy indicated that the complexes interact with the DNA minor groove and exhibit an HSA binding affinity.

Asunto(s)

Antineoplásicos/farmacología , Complejos de Coordinación/farmacología , Tiourea/análogos & derivados , Tiourea/farmacología , Antineoplásicos/síntesis química , Antineoplásicos/metabolismo , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Complejos de Coordinación/síntesis química , Complejos de Coordinación/metabolismo , ADN/metabolismo , Ensayos de Selección de Medicamentos Antitumorales , Puntos de Control de la Fase G1 del Ciclo Celular/efectos de los fármacos , Humanos , Ligandos , Estructura Molecular , Rutenio/química , Albúmina Sérica Humana/metabolismo , Tiourea/metabolismo

RESUMEN

BACKGROUND: An arteriovenous fistula (AVF) is the preferred vascular access for long-term hemodialysis. The main disadvantage of AVF is the rate of nonmaturation or unsuccessful use for hemodialysis (FUHD). We described our findings in AVF creation and possible risk factors associated with FUHD. METHODS: This is a retrospective study of AVFs during a 6-year period. Variables collected at the time of creation were demographics, comorbidities, replacement therapy, preoperative laboratory tests, and estimated 6-month mortality on hemodialysis. All AVFs were created in the upper arms. Outcomes were FUHD, cannulation failure, and cumulative survival. Univariate and multivariate analyses were performed to find possible risk factors for FUHD. RESULTS: AVFs were created in 78 patients. Average age was 36.3 years, and 74.4% were male. Mean body mass index was 24.5 kg/m2. The most common etiologies were glomerulopathy (53.6%) and diabetes mellitus (13.4%). Estimated six-month mortality was 4.2%. One patient underwent AVF before hemodialysis (mean dialysis time 2.2 years). Nineteen AVFs were considered FUHD (23.2%). Cannulation failure was 15.9%. AVF 1-year and 3-year survival was 67.8% and 63.5%, respectively. FUHD had higher estimated six-month mortality on hemodialysis, shorter prothrombin time, and lower serum albumin level than successful AVF (univariate analysis) (P < 0.05) Short prothrombin time and albumin were confirmed for FUHD (multivariate analysis). A 3.3-gr/dL serum albumin cutoff point (area under the curve, 0.715; receiver operating characteristic) (P < 0.05) was determined for FUHD. CONCLUSIONS: The population referred for AVF creation possesses different characteristics in our center. Good AVF outcomes can be achieved. Preoperative serum albumin level and prothrombin time could be the possible risk factors associated with unsuccessful AVF use.

Asunto(s)

Derivación Arteriovenosa Quirúrgica/efectos adversos , Fallo Renal Crónico/terapia , Diálisis Renal , Adulto , Anciano , Derivación Arteriovenosa Quirúrgica/mortalidad , Biomarcadores/sangre , Coagulación Sanguínea , Femenino , Humanos , Fallo Renal Crónico/sangre , Fallo Renal Crónico/diagnóstico , Fallo Renal Crónico/mortalidad , Masculino , México , Persona de Mediana Edad , Tiempo de Protrombina , Diálisis Renal/efectos adversos , Diálisis Renal/mortalidad , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Albúmina Sérica Humana/metabolismo , Factores de Tiempo , Insuficiencia del Tratamiento , Adulto Joven

RESUMEN

The thermodynamics and kinetics of binding between human serum albumin (HSA) and resveratrol (RES) or its analog (RESAn1) were investigated by surface plasmon resonance (SPR). The binding constant and the kinetic constants of association and dissociation indicated that RESAn1 has higher affinity toward HSA than does RES. The formation of these complexes was entropically driven ( [Formula: see text] , [Formula: see text]  KJ mol-1). However, for both polyphenols, the activation energy (Eact) of association (a) of free molecules was higher than that for dissociation (d) of the stable complex ( [Formula: see text]  KJ mol-1), and the rate of association was faster than that of dissociation since the activation Gibbs free energy (ΔG‡) was lower for the former (ΔGaHSA-RES‡â‰…54.73,ΔGdHSA-RES‡â‰…73.83,ΔGaHSA-RESAn1‡â‰…54.14,ΔGdHSA-RESAn1‡â‰…73.97 KJ mol-1). This study showed that small differences in the structure of polyphenols such as RES and RESAn1 influenced the thermodynamics and kinetics of the complex formation with HSA.

Asunto(s)

Fenoles/química , Resveratrol/metabolismo , Albúmina Sérica Humana/metabolismo , Humanos , Concentración de Iones de Hidrógeno , Proteínas Inmovilizadas/química , Proteínas Inmovilizadas/metabolismo , Cinética , Unión Proteica , Resveratrol/química , Albúmina Sérica Humana/química , Resonancia por Plasmón de Superficie , Temperatura , Termodinámica

RESUMEN

In the type II diabetes mellitus, Metformin hydrochloride is recommended as a common FAD approved drug. Synthesis of novel metformin series has been widely explored, mainly due to its biological importance and to improve their pharmacokinetic profile. Generally, human serum albumin (HSA) is the main protein used to study drug viability in vitro analysis. Thus, the present study reports the synthesis of three new halogenated metformin derivatives (MFCl, MFBr and MFCF3) and its interaction toward HSA by multiple spectroscopic techniques (UV-Vis, circular dichroism, steady-state, time-resolved and synchronous fluorescence), combined to computational methods (molecular docking and quantum chemical calculation). The interaction between each halogenated metformin derivative and HSA is spontaneous (ΔG°<0), entropically driven (ΔS°>0), moderate (Ka and Kb ≈ 104 M-1) and occurs preferentially in the subdomain IIA (close to Trp-214 residue). Molecular docking results suggested hydrogen bonding, van der Waals and hydrophobic interactions as the main binding forces. Quantum chemical calculations suggested imino groups as the most intense electrostatic negative potentials, while the positive electrostatic potential is located at the hydrogen atoms on N,N-dimethyl and the phenyl systems which can help the hydrophobic interactions. [Formula: see text]Communicated by Ramaswamy H. Sarma.

Asunto(s)

Diabetes Mellitus Tipo 2 , Metformina , Sitios de Unión , Dicroismo Circular , Humanos , Simulación del Acoplamiento Molecular , Unión Proteica , Albúmina Sérica Humana/metabolismo , Espectrometría de Fluorescencia , Termodinámica

RESUMEN

The steady rise in the cancer burden and grim statistics set a vital need for new therapeutic solutions. Given their high efficiency, metallodrugs are quite appealing in cancer chemotherapy. This work examined the anticancer activity of an anti-trypanosomal ruthenium-based compound bearing the 5-nitrofuryl pharmacophore, [RuII(dmso)2(5-nitro-2-furaldehyde semicarbazone)] (abbreviated as RuNTF; dmso is the dimethyl sulfoxide ligand). The cytotoxicity of RuNTF was evaluated in vitro against ovarian adenocarcinoma, hormone-dependent breast adenocarcinoma, prostate carcinoma (grade IV) and V79 lung fibroblasts human cells. The activity of RuNTF was similar to the benchmark metallodrug cisplatin for the breast line and inactive against the prostate line and lung fibroblasts. Given the known role of serum protein binding in drug bioavailability and the distribution via blood plasma, this study assessed the interaction of RuNTF with human serum albumin (HSA) by circular dichroism (CD) and fluorescence spectroscopy. The fluorescence emission quenching from the HSA-Trp214 residue and the lifetime data upon RuNTF binding evidenced the formation of a 1:1 {RuNTF-albumin} adduct with log Ksv = (4.58 ± 0.01) and log KB = (4.55 ± 0.01). This is supported by CD data with an induced CD broad band observed at ~450 nm even after short incubation times. Importantly, the binding to either HSA or human apo-transferrin is beneficial to the cytotoxicity of the complex towards human cancer cells by enhancing the cytotoxic activity of RuNTF.

Asunto(s)

Proteínas Sanguíneas/química , Complejos de Coordinación/química , Rutenio/química , Semicarbazonas/química , Algoritmos , Antineoplásicos/química , Antineoplásicos/farmacología , Proteínas Sanguíneas/metabolismo , Dicroismo Circular , Interacciones Farmacológicas , Humanos , Modelos Moleculares , Modelos Teóricos , Estructura Molecular , Unión Proteica , Rutenio/metabolismo , Albúmina Sérica Humana/química , Albúmina Sérica Humana/metabolismo

RESUMEN

Polyglycerol dendrimer synthesized from glycerol core (PGLyD) is an interesting reservoir macromolecule for the design of drug delivery systems due to their adequate blood biocompatibility. However, important features as the comprehension of the structural and dynamic characteristics and the interactions of PGLyD with blood proteins receptors remain unresolved. The high affinity and transport of HSA with drugs stimulated the docking simulations utilizing PGLyD as a ligand for the main HSA docking sites IIA and IIIA. HSA and the PGLyD structures were generated with the aid of Autodock Vina and the best conformations were determined by employing molecular docking. The molecular docking results indicate a thermodynamically favorable interaction suggesting a charge transfer complex formation between HSA and PGLyD. The interaction between PGLyD and HSA was investigated by fluorescence and the quenching mechanism of fluorescence of HSA by PGLyD was discussed. The binding constants and the number of binding sites were measured. The values of thermodynamic parameters ΔG, ΔH, and ΔS were calculated at three different temperatures. The experimental and computational results suggest that hydrophobic forces play a major role in stabilizing the HSA-PGLyD complex.

Asunto(s)

Dendrímeros/metabolismo , Glicerol/metabolismo , Polímeros/metabolismo , Albúmina Sérica Humana/metabolismo , Humanos , Simulación del Acoplamiento Molecular , Unión Proteica , Espectrometría de Fluorescencia , Termodinámica

RESUMEN

Piplartines are alkaloid amides present in the roots and stems of different pepper species which have promising pharmacological properties including cancer prevention. Some recent studies have determined pharmacokinetic parameters of piplartine in rat blood plasma but without pointing to any molecular target or describing the physicochemical forces of the interaction. The present study investigated the interaction between piplartine and human serum albumin (HSA) the predominant protein in blood plasma. Fluorescence spectroscopy was utilized to observe the complex HSA-piplartine formation. Thermodynamic parameter analysis indicates that the process occurs spontaneously and is enthalpically driven; the affinity constant suggests that this interaction is reversible. This was reinforced by the binding density function method and by the displacement analysis that the piplartine binds on HSA at a single site, which was determined to be the IIA sub-domain. In silico analysis (molecular docking) identified the main residues involved in binding and the corresponding forces, which corroborates well with the experimental results.

Asunto(s)

Piperidonas/química , Piperidonas/metabolismo , Albúmina Sérica Humana/química , Albúmina Sérica Humana/metabolismo , Sitios de Unión , Simulación por Computador , Humanos , Simulación del Acoplamiento Molecular , Espectrometría de Fluorescencia , Espectrofotometría Ultravioleta , Termodinámica

RESUMEN

BACKGROUND AND OBJECTIVES: Current hemodialysis techniques fail to efficiently remove the protein-bound uremic toxins p-cresyl sulfate and indoxyl sulfate due to their high degree of albumin binding. Ibuprofen, which shares the same primary albumin binding site with p-cresyl sulfate and indoxyl sulfate, can be infused during hemodialysis to displace these toxins, thereby augmenting their removal. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We infused 800 mg ibuprofen into the arterial bloodline between minutes 21 and 40 of a conventional 4-hour high-flux hemodialysis treatment. We measured arterial, venous, and dialysate outlet concentrations of indoxyl sulfate, p-cresyl sulfate, tryptophan, ibuprofen, urea, and creatinine before, during, and after the ibuprofen infusion. We report clearances of p-cresyl sulfate and indoxyl sulfate before and during ibuprofen infusion and dialysate concentrations of protein-bound uremic toxins normalized to each patient's average preinfusion concentrations. RESULTS: We studied 18 patients on maintenance hemodialysis: age 36±11 years old, ten women, and mean vintage of 37±37 months. Compared with during the preinfusion period, the median (interquartile range) clearances of indoxyl sulfate and p-cresyl sulfate increased during ibuprofen infusion from 6.0 (6.5) to 20.2 (27.1) ml/min and from 4.4 (6.7) to 14.9 (27.1) ml/min (each P<0.001), respectively. Relative median (interquartile range) protein-bound uremic toxin dialysate outlet levels increased from preinfusion 1.0 (reference) to 2.4 (1.2) for indoxyl sulfate and to 2.4 (1.0) for p-cresyl sulfate (each P<0.001). Although median serum post- and predialyzer levels in the preinfusion period were similar, infusion led to a marked drop in serum postdialyzer levels for both indoxyl sulfate and p-cresyl sulfate (-1.0 and -0.3 mg/dl, respectively; each P<0.001). The removal of the nonprotein-bound solutes creatinine and urea was not increased by the ibuprofen infusion. CONCLUSIONS: Infusion of ibuprofen into the arterial bloodline during hemodialysis significantly increases the dialytic removal of indoxyl sulfate and p-cresyl sulfate and thereby, leads to greater reduction in their serum levels.

Asunto(s)

Cresoles/sangre , Ibuprofeno/administración & dosificación , Indicán/sangre , Diálisis Renal , Albúmina Sérica Humana/metabolismo , Ésteres del Ácido Sulfúrico/sangre , Uremia/terapia , Adulto , Unión Competitiva , Femenino , Humanos , Ibuprofeno/efectos adversos , Ibuprofeno/sangre , Infusiones Intraarteriales , Masculino , Persona de Mediana Edad , Unión Proteica , Diálisis Renal/efectos adversos , Factores de Tiempo , Resultado del Tratamiento , Uremia/sangre , Uremia/diagnóstico

RESUMEN

Thiosemicarbazone is a class of compounds with potential applications in medicine, presenting high capacity to inhibit the growth of cancer cells as well as low toxicity. Because of high interest in anticancer studies involving thiosemicarbazones as new chemotherapeutic agents, a synthetic thiosemicarbazone derivative, 4-N-(2'-methoxy-styryl)-thiosemicarbazone (MTSC) was evaluated in vivo against Ehrlich carcinoma in an animal model. In vivo results demonstrated that MTSC treatment induced the survival of mice and altered significantly the body weight of the surviving mice 12 days after tumor inoculation. Treatment with 30 mg/kg of MTSC exhibited effective cytotoxic activity with T/C values of 150.49% (1 dose) and 278% (2 doses). Its interaction with human serum albumin (HSA), which plays a crucial role in the biodistribution of a wide variety of ligands, was investigated by multiple spectroscopic techniques at 296 K, 303 K, and 310 K, as well as by theoretical calculations. The interaction between HSA and MTSC occurs via ground-state association in the subdomain IIA (Sudlow's site I). The binding is moderate (Ka ≈ 104 M-1), spontaneous, entropically, and enthalpically driven. Molecular docking results suggested hydrogen bonding and hydrophobic interactions as the main binding forces. Overall, the interaction HSA:MTSC could provide therapeutic benefits, improving its cytotoxic efficacy and tolerability.

Asunto(s)

Antineoplásicos/farmacología , Carcinoma de Ehrlich/patología , Leucemia Eritroblástica Aguda/patología , Albúmina Sérica Humana/metabolismo , Tiosemicarbazonas/farmacología , Animales , Antineoplásicos/química , Apoptosis , Carcinoma de Ehrlich/tratamiento farmacológico , Carcinoma de Ehrlich/metabolismo , Proliferación Celular , Femenino , Humanos , Técnicas In Vitro , Leucemia Eritroblástica Aguda/tratamiento farmacológico , Leucemia Eritroblástica Aguda/metabolismo , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Simulación del Acoplamiento Molecular , Unión Proteica , Conformación Proteica , Albúmina Sérica Humana/química , Tiosemicarbazonas/química , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de Xenoinjerto

RESUMEN

Due to the high sensitivity to alterations in microenvironment polarity of macromolecules, pyrene and its derivatives have long been applied in biosciences. Human serum albumin (HSA), besides its numerous physiological functions, is the main responsible by transport of endogenous and exogenous compounds in the circulatory system. Here, a comprehensive study was carry out to understand the interaction between HSA and the pyrene derivative 1-pyrenesulfonic acid (PMS), which showed a singular behaviour when bound to this protein. The complexation of PMS with HSA was studied by steady state, time-resolved and anisotropy fluorescence, induction of circular dichroism (ICD) and molecular docking. The fluorescence quenching of PMS by HSA was abnormal, being stronger at lower concentration of the quencher. Similar behaviour was obtained by measuring the ICD signal and fluorescence lifetime of PMS complexed in HSA. The displacement of PMS by site-specific drugs showed that this probe occupied both sites, but with higher affinity for site II. The movement of PMS between these main binding sites was responsible by the abnormal effect. Using the holo (PDB: ID 1A06) and apo (PDB: ID 1E7A) HSA structures, the experimental results were corroborated by molecular docking simulation. The abnormal spectroscopic behaviour of PMS is related to its binding in different regions in the protein. The movement of PMS into the protein can be traced by alteration in the spectroscopic signals. These findings bring a new point of view about the use of fluorescence quenching to characterize the interaction between albumin and ligands.

Asunto(s)

Conalbúmina/metabolismo , Pirenos/metabolismo , Albúmina Sérica Bovina/metabolismo , Albúmina Sérica Humana/metabolismo , Ácidos Sulfónicos/metabolismo , Animales , Anisotropía , Sitios de Unión , Bovinos , Dicroismo Circular , Fluorescencia , Humanos , Simulación del Acoplamiento Molecular , Pirenos/química , Ácidos Sulfónicos/química , Termodinámica , Factores de Tiempo , Triptófano/análogos & derivados , Triptófano/química

RESUMEN

N-(2-hydroxyphenyl)-2-propylpentanamide (HO-AAVPA) is a novel valproic acid derivative that has shown anti-proliferative activity against epitheloid cervix carcinoma (HeLa), rhabdomyosarcoma (A204), and several breast cancer cell lines. The aim of this research was to evaluate the pharmacokinetic profile and tissue distribution of HO-AAVPA in Wistar rats, as well as its human serum albumin binding potential by experimental and in silico methods. A single dose of HO-AAVPA was given to male rats by intravenous, intragastric or intraperitoneal routes at doses of 25, 100, and 100 mg/kg, respectively. Then, blood samples were drawn at predetermined intervals of time, and the HO-AAVPA concentration in the plasma was quantified with a validated HPLC method. The elimination half-life (t1/2) was approximately 222 min, and the systemic clearance (CL) and apparent volume of distribution (Vd) were 2.20 mL/min/kg and 0.70 L/kg, respectively. The absolute oral bioavailability of HO-AAVPA was 33.8%, and the binding rate of HO-AAVPA with rat plasma proteins was between 66.2% and 83.0%. Additionally, in silico, UV and Raman spectroscopy data showed weak interactions between the test compound and human serum albumin. Thus, the results that were obtained demonstrated that despite its low oral bioavailability, the potential anticancer agent HO-AAVPA exhibits acceptable pharmacokinetic properties that would allow it to reach its site of action and exert its pharmacological effect in Wistar Rats, and it has a convenient profile for future assays to evaluate its human applications.

Asunto(s)

Amidas/farmacocinética , Antineoplásicos/farmacocinética , Pentanos/farmacocinética , Albúmina Sérica Humana/metabolismo , Ácido Valproico/farmacocinética , Administración Oral , Amidas/administración & dosificación , Amidas/sangre , Animales , Antineoplásicos/administración & dosificación , Antineoplásicos/sangre , Sitios de Unión , Disponibilidad Biológica , Inyecciones Intraperitoneales , Inyecciones Intravenosas , Masculino , Simulación del Acoplamiento Molecular , Simulación de Dinámica Molecular , Pentanos/administración & dosificación , Pentanos/sangre , Unión Proteica , Ratas Wistar , Distribución Tisular , Ácido Valproico/administración & dosificación , Ácido Valproico/sangre

RESUMEN

Acridines are considered an important class of compounds due to their wide variety of biological activities. In this work, we synthesized four acridine derivatives (1-4) and evaluated their biological activity against the Plasmodium falciparum W2 line, as well as studied the interaction with ctDNA and HSA using spectroscopic techniques and molecular docking. The acridine derivative 2 (IC50 = 0.90 ±â€¯0.08 µM) was more effective against P. falciparum than primaquine (IC50 = 1.70 ±â€¯0.10 µM) and similar to amsacrine (IC50 = 0.80 ±â€¯0.10 µM). In the fluorescence and UV-vis assays, it was verified that the acridine derivatives interact with ctDNA and HSA leading to a non-fluorescent supramolecular complex formation. The non-covalent binding constants ranged from 2.09 to 7.76 × 103 M-1, indicating moderate interaction with ctDNA. Through experiments with KI, fluorescence contact energy transfer and competition assays were possible to characterize the main non-covalent binding mode of the acridines evaluated with ctDNA as intercalation. The binding constants obtained showed a high linear correlation with the IC50 values against the antimalarial activity, suggesting that DNA may be the main biological target of these molecules. Finally, HSA interaction studies were performed and all evaluated compounds bind to the site II of the protein. The less active compounds (1 and 3) presented the highest affinity to HSA, indicating that the interaction with carrier protein can affect the (bio)availability of these compounds to the biological target.

Asunto(s)

Acridinas/síntesis química , Antimaláricos/farmacología , ADN/metabolismo , Albúmina Sérica Humana/metabolismo , Acridinas/farmacología , Sitios de Unión , Humanos , Sustancias Intercalantes/farmacología , Unión Proteica , Relación Estructura-Actividad