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Jallat S.; Carvallo D.; Tessier L.H.; Roecklin D.; Roitsch C.; Ogushi F.; Crystal R.G.; Courtney M. 《Protein engineering, design & selection : PEDS》1986,1(1):29-35
Seven active site variants of human 1-antitrypsin (1AT) wereproduced in Escherichia coli following site-specific mutagenesisof the 1AT complementary DNA. 1AT (Ala 358), 1AT (Ile358 and1AT (Val358), were efficient inhibitors of both neutrophil andpancreatic elastases, but not of cathepsin G. 1AT (Ala358, Val358)and 1AT (Phe358 specifically inhibited pancreatic elastase andcathepsin G respectively. The most potent inhibitor of neutrophilelastase was 1AT (Leu358), which also proved to be effectiveagainst cathepsin G. The 1AT (Arg358) variant inactivated thrombinwith kinetics similar to antithrombin III in the presence ofheparin. Electrophoretic analysis showed that SDS-stable highmol. wt complexes were formed between the mutant inhibitorsand the cognate proteases in each case. These data indicatethat effective inhibition occurs when the 1AT P1 residue (position358) corresponds to the primary specificity of the target protease.Moreover, alteration of the P3 residue (position 356) can furthermodify the reactivity of the inhibitor. Two of the variantshave therapeutic potential: 1AT (Leu358 may be more useful thanplasma 1AT in the treatment of destructive lung disorders and1 (Arg358 could be effective in the control of thrombosis. 相似文献
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C Jallat V Livrelli A Darfeuille-Michaud C Rich B Joly 《Canadian Metallurgical Quarterly》1993,31(8):2031-2037
Two hundred sixty-two strains of Escherichia coli isolated from diarrheal stool specimens from infants, children, and adults hospitalized in Clermont-Ferrand, France, were studied to classify them in the previously described pathogenic groups of E. coli involved in diarrheal diseases. A total of 1.5% of them belonged to the enterotoxigenic E. coli pathotype, but none belonged to the enteroinvasive E. coli, enterohemorrhagic E. coli, or enteropathogenic E. coli pathotypes. Seventeen strains (6.5%) exhibited an aggregative pattern of adhesion to HEp-2 cells (EAggEC pathotype), but of these, three (17.6%) did not hybridize with the EAggEC DNA probe. Most of the strains involved in diarrhea belonged to the diffusely adhering E. coli group; 100 strains (38.2%) exhibited a diffuse adhesion (DA) to HEp-2 cells. Only eight strains (8.9%) from controls diffusely adhered to HEp-2 cells. The highly significant difference (P < 0.0001) between DA strains from patients and from controls suggests that the diffusely adhering E. coli strains should be considered pathogens. Only 33 of them (33%) hybridized with the previously described DA DNA probe, and only 2 (2%) hybridized with the AIDA DNA probe. Four different major proteins were observed in the bacterial surface extracts of the 33 strains positive with the DA DNA probe. In addition, 16 strains that diffusely adhered to HEp-2 cells induced a cytotoxic effect on HEp-2 cells that was characterized by pyknosis and lysis of the cytoplasmic membrane. This cytotoxic effect was correlated with the synthesis of a hemolysin. The genes involved in diffuse adhesion to HEp-2 cells were located on conjugative R plasmids in strains that did not hybridize with the DA or AIDA DNA probes. 相似文献
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