RESUMO
The modified asparaginase Was79 was derived from the recombinant wild-type L-asparaginase of Wolinella succinogenes. The Was79 contains the amino acid substitutions V23Q and K24T responsible for the resistance to trypsinolysis and the N-terminal heparin-binding peptide KRKKKGKGLGKKR responsible for the binding to heparin and tumor K562 cells in vitro. When tested on a mouse model of Fischer lymphadenosis L5178Y, therapeutic efficacy of Was79 was significantly higher than that of reference enzymes at all single therapeutic doses used (125-8000 IU/kg). At Was79 single doses of 500-8000 IU/kg, the complete remission rate of 100 % was observed. The Was79 variant can be expressed intracellularly in E. coli as a less immunogenic formyl-methionine-free form at high per cell production levels.
Assuntos
Antineoplásicos/administração & dosagem , Asparaginase/genética , Asparaginase/metabolismo , Heparina/metabolismo , Leucemia L5178/tratamento farmacológico , Wolinella/enzimologia , Substituição de Aminoácidos , Animais , Antineoplásicos/farmacologia , Asparaginase/administração & dosagem , Asparaginase/farmacologia , Proteínas de Bactérias/administração & dosagem , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/farmacologia , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Humanos , Células K562 , Camundongos , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/farmacologia , Wolinella/genética , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The influence of new synthetic peptides ARGDS-NH2 and RGD-dFK (synthesized by the fermentative method) and VPNLRGDLQVLA (a fragment of the foot-and-mouth virus's surface peptide) on the ADP-induced human platelet aggregation in vitro was studied. All peptides were found to inhibit the human platelet aggregation, but the synthetic peptides (ARGDS-NH2 and RGD-dFK) showed the most pronounced effect. Significant decrease in the platelet aggregation was observed at their concentrations within 0.1-10 mM. ARGDS-NH2 and RGD-dFK inhibited the platelet aggregation stronger than the reference drug pentoxifylline at equivalent concentrations.
Assuntos
Oligopeptídeos/farmacologia , Inibidores da Agregação Plaquetária/farmacologia , Agregação Plaquetária/efeitos dos fármacos , Vírus da Febre Aftosa , Humanos , Técnicas In Vitro , Oligopeptídeos/química , Pentoxifilina/farmacologia , Inibidores da Agregação Plaquetária/química , Testes de Função Plaquetária , Proteínas do Core Viral/químicaRESUMO
Subtilisin 72 sorbed on the surface of macroporous glass catalyzes a condensation of the esters of N-acylated peptides with arginine derivatives in organic solvents. The sorbed enzyme can be used repeatedly, which makes it possible to synthesize the chromophore substrates of metalloproteinases and carbopeptidases of the general formula Dnp-Ala-Ala-Xaa-Arg-NH2 (Xaa = Leu, Phe, Val, Ile). In tetrapeptides, metalloproteinases hydrolyze the Ala-Xaa bond with the removal of Dnp-Ala-Ala-OH, which can be determined spectrophotometrically. The chromophore substrates of carboxypeptidases of the B type (Dnp-Ala-Ala-Xaa-Arg-OH and Dnp-Ala-Ala-Arg-OH) are obtained by hydrolysis of the corresponding amides by trypsin.
Assuntos
Arginina/química , Carboxipeptidases/metabolismo , Metaloendopeptidases/metabolismo , Peptídeos/síntese química , Sequência de Aminoácidos , Compostos Cromogênicos , Dados de Sequência Molecular , Peptídeos/metabolismo , Especificidade por SubstratoRESUMO
The formyl group transfer from N-formyl amino acids and their derivatives to other acceptors--amino acids esters and aniline, was studied. Formylamino acids with the free alpha-carboxyl group are more effective donors in transformylation than formyl peptides or esters of formylamino acids.