ABSTRACT
Objective To establish a chromogenic assay for blood-plasma collagenase Ⅳ in order to evaluation the reference range of collagenase Ⅳ in the plasma of healthy individuals.Methods The assay was based on measurement of terminal amino group with succinylated gelatin as substrates and TNBS as chromogenic reagent.The optical density of each reaction was determined at 405 nm using a Sunrise microplate reader.Chromatographic and detection conditions were optimized and performance of the methed was evaluated by recovery experiments and precision experiments.It was compared with ELISA.The levels of collagenase Ⅳ in 112 health persons'plasma were determined and the data were analyzed by SPSS statistical software.Results The whole determing time was within 1.5 h,the linear range of this method was 1.5-10.0 mg/L,and the minimum detection limit was 0.965 mg/L.They were well correlated with ELISA results (R~2=0.999 7,P＜0.01).The within-run CV was less than 3.16%and between-run CV was less than 9.81%.The 95%confidence interval of collagenase Ⅳ in healthy plasma was 33.38-49.80 mg/L.Conclusion This chromogenic assay for blood-plasma collagenase Ⅳ can be used for measurement of collagenase Ⅳ in blood-plasma and the reference range of collagenase Ⅳ in healthy plasma was established.
ABSTRACT
Objective A high-performance liquid chromatography(HPLC)method was modified and used to determine the inhibitory effects of GM6001 and inhibitor A on tumor necrosis factor-α converting enzyme(TACE).Methods TACE and polypeptides substrate were incubated for 15 min at 37°C.Ala-Dpa was added as internal standard of quantitative analysis.Then the solution was analyzed by HPLC.The 55% methanol aqueous solution was used as the mobile phase.The wavelength of detector was 353 nm.The ratio of the peak area of remaining substrate to that of internal standard was determined.And the amounts of inverted substrate could be obtained from calibration curve.The TACE activity could be calculated.Results The relative peak areas of substrate were linearly increased depending on the growth of substrate concentration.The correlation coefficient was 0.996 8 and linear range was from 10 to 400 μmol/L.Precision experiments indicated that the precision was improved obviously by using internal standard method in the determination of TACE activity by HPLC.The values of 50% inhibitory concentration IC50 of GM6001 and inhibitor A determined by the newly proposed method were 317.5 and 175.8 nmol/L,respectively.Conclusion The HPLC method assaying TACE activity with Ala-Dpa as internal standard is more accurate,and more practical for screening of TACE inhibitors.
ABSTRACT
The crystal structural data of TACE, MMP-1, MMP-2, MMP-3 and MMP-9 were obtained from PDB database, and then their catalytic domains' properties including conformation, molecular surface hydrophobicity and electrostatic potential were analyzed and compared by using Insight Ⅱ molecular modeling software. It was found that the conformation and molecular surface hydrophobicity of catalytic domains of TACE and MMPs were not obviously different, but the molecular surface electrostatic potential of catalytic domain of TACE and MMPs had obvious differences.The findings are helpful in the Rational Drug Design of TACE selective inhibitor.
ABSTRACT
The crystal structural data of TACE, MMP-1, MMP-2, MMP-3 and MMP-9 were obtained from PDB database, and then their catalytic domains' properties including conformation, molecular surface hydrophobicity and electrostatic potential were analyzed and compared by using Insight II molecular modeling software. It was found that the conformation and molecular surface hydrophobicity of catalytic domains of TACE and MMPs were not obviously different, but the molecular surface electrostatic potential of catalytic domain of TACE and MMPs had obvious differences. The findings are helpful in the Rational Drug Design of TACE selective inhibitor.