ABSTRACT
Objective To analyze molecular evolution and binding free energies of cephalosporinase ADC-57.Methods Minimum Evolution method in MEGA 5.0 was used to analyze molecular evolution of cephalosporinase ADC-57 and other 19 kinds of beta-lactamases.Tertiary structure of ADC-57 was predicted by homology modeling referring to tertiary structure of CMY-2.The molecular docking of ADC-57 to 11kinds of beta-lactams substrates was performed using DOCK module in ArgusLab 4.1and the binding free energies (△G) was calculated.Results ADC-57,CMY-2,DHA-1,ADC-7,ADC-56 were all belong to class C beta-lactamase,and molecular evolution between ADC-57 and ADC-56 was closest.The top three antibiotics with declining binding free energy of beta-lactams were ertapenem,cefoxitin and ceftazidine,while the last two were clavulanic acid and aztreonam.Conclusions Catalytic activities of cephalosporinase ADC-57 to ertapenem,cefoxitin and ceftazidine are high,while to clavulanic acid and aztreonam are low. Hydrolytic activities of enzyme to beta-lactams (substrates) can be analyzed by molecular docking.
ABSTRACT
Objective To detect the levels of plasminogen activator inhibitor(PAI)-1,tissue plasminogen activator(t-PA),urokinase-type plasminogen activator(u-PA)and urokinase-type plasminogen activator receptor(u-PAR)in induced sputum in patients with asthma and analyze their clinical significances in pathogenesis of asthlna.Methods The induced sputum was isolated from 15 normal subjects(control group),29 patients with acute attack of asthma(attack group)and 26 stable asthma patients(stable group).The levels of PAl-1,t-PA,u-PA and u-PAR were measured by ELISA.Meanwhile FEV1%pred of all groups were evaluated.Results The levels of PAI-1 and u-PAR of induced sputum were significandy higher in at-tack group[(23.32±21.64),(0.766±0.272)μg/L]and stable group[(17.23±9.40),(0.700±0.271)μg/L]than those in control group[(5.99±5.04),(0.516±0.197)μg/L](P＜0.05).As for the induced sputum concentrations of u-PA and t-PA,there were no significant differences among the attack group[(0.287±0.235),(7.68±3.46)μg/L],stable group[(0.251±0.276),(9.88±4.68)μg/L]and control group[(0.239±0.322),(10.35±7.47)μg/L].In stable group,the level of PAI-1 had a negative correlation with the FEV1%pred(r=-0.756,P＜0.01).In stable group,the level of PAI-1 had a positive correlation with the length of disease course(r=0.454,P＜0.05).Conclusion PAI-1 and u-PAR maybe involved in pathophysiologic change of asthma.