RESUMEN
The author presents the results of the surveillance of medical rehabilitation of 22 elderly patients suffering from chemical stomatitis combined with medication sialadenopathys that occurred after combined treatment of malignant tumors of oropharyngeal area. It is shown that the inclusion in the conventional regimen chemical stomatitis peptide bioregulator Vezugen and dietary supplement Algiklam enhances the effectiveness of the treatment gerontostomatologic patients suffering from chemical stomatitis combined with medication sialadenopathys.
Asunto(s)
Proteínas Bacterianas/química , Cristalografía por Rayos X/métodos , Geobacillus stearothermophilus/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Geobacillus stearothermophilus/genética , Factores de Transcripción/química , Factores de Transcripción/genética , Factores de Transcripción/metabolismoRESUMEN
GCN5-related N-acetyltransferases (GNATs) are the most widely distributed acetyltransferase systems among all three domains of life. GNATs appear to be involved in several key processes, including microbial antibiotic resistance, compacting eukaryotic DNA, controlling gene expression, and protein synthesis. Here, we report the crystal structure of a putative GNAT Ta0374 from Thermoplasma acidophilum, a hyperacidophilic bacterium, that has been determined in an apo-form, in complex with its natural ligand (acetyl coenzyme A), and in complex with a product of reaction (coenzyme A) obtained by cocrystallization with spermidine. Sequence and structural analysis reveals that Ta0374 belongs to a novel protein family, PaiA, involved in the negative control of sporulation and degradative enzyme production. The crystal structure of Ta0374 confirms that it binds acetyl coenzyme A in a way similar to other GNATs and is capable of acetylating spermidine. Based on structural and docking analysis, it is expected that Glu53 and Tyr93 are key residues for recognizing spermidine. Additionally, we find that the purification His-Tag in the apo-form structure of Ta0374 prevents binding of acetyl coenzyme A in the crystal, though not in solution, and affects a chain-flip rotation of "motif A" which is the most conserved sequence among canonical acetyltransferases.
Asunto(s)
Acetiltransferasas/química , Proteínas Arqueales/química , Cristalografía por Rayos X/métodos , Thermoplasma/enzimología , Secuencia de Aminoácidos , Modelos Moleculares , Datos de Secuencia Molecular , Estructura Secundaria de Proteína , Homología de Secuencia de AminoácidoRESUMEN
NAD(+)-dependent formate dehydrogenase (FDH) catalyzes the oxidation of formate ion to carbon dioxide coupled with the reduction of NAD(+) to NADH. The crystal structures of the apo and holo forms of FDH from the methylotrophic bacterium Moraxella sp. C-1 (MorFDH) are reported at 1.96 and 1.95 A resolution, respectively. MorFDH is similar to the previously studied FDH from the bacterium Pseudomonas sp. 101 in overall structure, cofactor-binding mode and active-site architecture, but differs in that the eight-residue-longer C-terminal fragment is visible in the electron-density maps of MorFDH. MorFDH also differs in the organization of the dimer interface. The holo MorFDH structure supports the earlier hypothesis that the catalytic residue His332 can form a hydrogen bond to both the substrate and the transition state. Apo MorFDH has a closed conformation of the interdomain cleft, which is unique for an apo form of an NAD(+)-dependent dehydrogenase. A comparison of the structures of bacterial FDH in open and closed conformations allows the differentiation of the conformational changes associated with cofactor binding and domain motion and provides insights into the mechanism of the closure of the interdomain cleft in FDH. The C-terminal residues 374-399 and the substrate (formate ion) or inhibitor (azide ion) binding are shown to play an essential role in the transition from the open to the closed conformation.
Asunto(s)
Formiato Deshidrogenasas/química , Moraxella/enzimología , Secuencia de Aminoácidos , Apoenzimas/química , Apoenzimas/metabolismo , Sitios de Unión , Biocatálisis , Cristalografía por Rayos X , Formiato Deshidrogenasas/metabolismo , Holoenzimas/química , Holoenzimas/metabolismo , Modelos Moleculares , Datos de Secuencia Molecular , Multimerización de Proteína , Estructura Cuaternaria de Proteína , Estructura Terciaria de Proteína , Alineación de Secuencia , Especificidad por SustratoRESUMEN
The authors provide evidence on the condition of external respiration and hemodynamic shifts in the lesser and greater circulation in coronary patients with bundle-branch block; establish early objective quantitative criteria of the diagnosis of hemodynamic impairment arising in formation of the above blocks basing on ECG, phonocardiography, echocardiography findings; compare hemodynamic effects of single-dose nitrosorbide and corinfar in the above patients. Nitrosorbide and corinfar correct hemodynamics and external respiration, the former being more effective in normalizing the greater, while corinfar the lesser circulation.