RESUMO
Recent advancements in enzyme research have unveiled a new proteoform of bovine trypsin, expanding our understanding of this well-characterized enzyme. While generally similar to other trypsins, this novel proteoform comprises three polypeptide chains, marking a significant difference in activity, kinetic properties, and conformational stability. Compared with the already known bovine trypsin proteoforms, the results showed a lower: activity, kcat and kcat.KM-1 and protein 'foldedness' ratio for the new proteoform. Molecular autolysis, a common feature in trypsin and chymotrypsin, has been explored through comparative physical chemistry properties with other proteoforms. This new proteoform of trypsin not only enriches the existing enzyme repertoire but also promises to shed light on the intricate physiological pathway for enzyme inactivation. Our results suggest that the new trypsin proteoform is one of the likely final pathways for enzyme inactivation in a physiological environment. This discovery opens up new avenues for further research into the functional implications of this new trypsin proteoform.
Assuntos
Tripsina , Tripsina/química , Tripsina/metabolismo , Animais , Bovinos , Cinética , Estabilidade Enzimática , Conformação ProteicaRESUMO
The α-trypsin isoform is a globular protein that belongs to serine-protease family and has a polypeptide chain of 223 amino acid residues, six disulfide bridges and two domains with similar structures. The effects of aqueous-organic solvent (ethanol) in different concentration on the α-trypsin structure have been investigated by spectroscopic techniques and thermodynamic data analysis. The results from spectroscopic measurements, including far-UV Circular Dichroism, UV-vis absorption spectroscopy, intrinsic tryptophan fluorescence and dynamic light scattering (DLS) suggest the formation of partially folded states, instead of aggregate states, at high ethanol concentration (>60% v/v ethanol), with little loss of secondary structure, but with significant tertiary structure changes. The thermodynamic data (Tm and ΔH) suggest a loosening of intramolecular weak interactions, which reflects in a flexibility increase such that the catalytic capacity can be increased or decreased according to the ethanol concentration into the system. Overall results we suggest that in range of 0-60% v/v ethanol/buffer, α-trypsin undergoes reversible multimerization phenomena with catalytic activity. However from 60% v/v ethanol/buffer, population of folded partially states with less catalytic activity are predominant.
Assuntos
Etanol/farmacologia , Tripsina/química , Tripsina/metabolismo , Água/química , Animais , Biocatálise , Bovinos , Relação Dose-Resposta a Droga , Estabilidade Enzimática/efeitos dos fármacos , Isoenzimas/química , Isoenzimas/metabolismo , Estrutura Secundária de Proteína , TermodinâmicaRESUMO
A novel bovine trypsin isoform was purified from commercial sample by ion exchange chromatography by Sephadex SP C50®. New isoform contains in addition of loss of N-terminus hexapeptide (as found in parent molecule ß-trypsin) an intra-chain split between Lys-155 and Ser-156. The novel enzyme denominate γ-trypsin showed similar properties with α-trypsin isoform in polypeptide number chain (two chain), molecular masses (23,312 Da), secondary structure, hydrodynamic radius and others. In spite of enzymatic and structural similarities of both isoforms, γ-trypsin preferably has a lower rate formation from ß-trypsin, a lower surface charge, but the γ-trypsin has a higher thermal stability than α-trypsin. Due to obtaining facility of purification of bovine trypsin isoforms from commercial font, and properties described above, this enzyme becomes an interesting alternative for the food industry, detergent and biocatalysis research.
Assuntos
Tripsina/química , Animais , Bovinos , Ativação Enzimática , Estabilidade Enzimática , Isoenzimas , Modelos Moleculares , Peso Molecular , Peptídeos/química , Desnaturação Proteica , Domínios e Motivos de Interação entre Proteínas , Estrutura Secundária de Proteína , Termodinâmica , Tripsina/isolamento & purificação , Tripsina/metabolismoRESUMO
Objetivo. Descrever dados clínicos, laboratoriais e de anatomia patológica em uma paciente portadora de arteritede Takayasu coexistente com tuberculose. Enfatiza-se o papel dos estudos de autopsia para revelar associaçõesentre enfermidades que podem permanecer sem diagnóstico ou não informadas, quando se baseia exclusivamenteem dados clínicos.Relato do caso. Descreve-se o caso de mulher com 17 anos de idade, portadora de arterite de Takayasu coexistentecom sequelas de tuberculose no pulmão e em linfonodos. Ela apresentou síncope e ausência de pulso nobraço direito provavelmente devido à síndrome do roubo da subclávia.Conclusão. A associação causal entre a arterite de Takayasu e tuberculose tem sido sugerida, mas o papel doMycobacterium tuberculosis não está completamente esclarecido nessa condição. Essa arterite é rara em nossopaís, mas sua prevalência vem aumentando. Embora a freqüência de tuberculose seja elevada no Brasil, estudos deautopsia sobre a arterite de Takayasu concomitante com tuberculose têm sido muito raramente publicados.
Objective. Clinical, laboratory and pathology findings are described in a patient with Takayasu?s arteritis coexistingwith tuberculosis, and the role of the autopsy studies is emphasized to detect associations between diseases, whichmay persist underdiagnosed or underreported if strictly based on the clinical data.Case report. The case of a 17-year-old female with Takayasu?s arteritis coexistent with lung and lymph nodesequels of tuberculosis is described. She presented with syncope and absence of pulse in the right arm likely due tosubclavian steal syndrome.Conclusion. Causal association between Takayasu?s arteritis and tuberculosis has been suggested, but the pathogenicrole of Mycobacterium tuberculosis is not entirely clear in this condition. This arteritis is rare in our country, but itsprevalence has increased. Although the prevalence of tuberculosis is high in Brazil, autopsy studies of simultaneousTakayasu?s arteritis and tuberculosis have been very rarely published.
RESUMO
Alcohol-related massive eyelid edema has been rarely reported. The differential diagnosis includes local and systemic conditions. Alcohol itself can be associated with dermatological hypersensitivity reactions, appearing soon after alcoholic drinks. Massive bilateral eyelid swelling can constitute diagnostic pitfalls and therapeutic challenges to general practitioners with a placebo.
Assuntos
Transtornos Relacionados ao Uso de Álcool/complicações , Edema/etiologia , Doenças Palpebrais/etiologia , Adulto , Humanos , MasculinoRESUMO
Alcohol-related massive eyelid edema has been rarely reported. The differential diagnosis includes local and systemic conditions. Alcohol itself can be associated with dermatological hypersensitivity reactions, appearing soon after alcoholic drinks. Massive bilateral eyelid swelling can constitute diagnostic pitfalls and therapeutic challenges to general practitioners with a placebo.
Edema palpebral maciço relacionado ao uso de álcool tem sido raramente descrito. O diagnóstico diferencial inclui condições locais e sistêmicas. O próprio álcool pode estar associado com reações dermatológicas de hipersensibilidade, surgindo logo após uso de bebidas alcoólicas. Edema palpebral bilateral maciço pode constituir embaraços diagnósticos e desafios terapêuticos para os clínicos.