Modeling the 3D structure of wheat subtilisin/chymotrypsin inhibitor (WSCI). Probing the reactive site with two susceptible proteinases by time-course analysis and molecular dynamics simulations
| Autor: | Antimo Di Maro, Simone Di Gennaro, Daniela Panichi, Augusto Parente, Elia Poerio, Susan Costantini, Angelo Facchiano, Angela Chambery |
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| Přispěvatelé: | Facchiano, Am, Costantini, S, DI MARO, A, Panichi, D, Chambery, A, Parente, A, DI GENNARO, S, Poerio, E |
| Rok vydání: | 2006 |
| Předmět: |
Models
Molecular Protein Conformation Molecular Sequence Data Clinical Biochemistry Protein Data Bank (RCSB PDB) Biochemistry Protein structure Recombinant WSCI Peptide bond Amino Acid Sequence Subtilisins Binding site Molecular Biology Peptide sequence Chromatography High Pressure Liquid Plant Proteins Binding Sites Chymotrypsin Sequence Homology Amino Acid biology Proteinase-inhibitor complex Chemistry Hydrolysis MALDI-TOF mass spectrometry Subtilisin Recombinant Proteins Reactive site Kinetics Molecular simulation Spectrometry Mass Matrix-Assisted Laser Desorption-Ionization biology.protein Electrophoresis Polyacrylamide Gel Proteinase inhibitor |
| Zdroj: | Biological Chemistry. 387:931-940 |
| ISSN: | 1437-4315 1431-6730 |
| DOI: | 10.1515/bc.2006.117 |
| Popis: | Comparative modeling and time-course hydrolysis experiments have been applied to investigate two enzyme-inhibitor complexes formed between the wheat subtilisin-chymotrypsin inhibitor (WSCI) and two susceptible proteinases. WSCI represents the first case of a wheat protein inhibitor active against animal chymotrypsins and bacterial subtilisins. The model was created using as template structure that of the CI-2A inhibitor from barley (PDB code: 2CI2), which shares 87% sequence identity with WSCI. Under these conditions of high similarity, the comparative modeling approach can be successfully applied. We predicted the WSCI 3D model and used it to investigate enzyme-inhibitor complex systems. Experimental observations indicated that chymotrypsin, but not subtilisin, in addition to cleavage at the primary reactive site Met48-Glu49, is able to hydrolyze a second peptide bond between Phe58 and Val59. Here, we report on cleavage of the peptide bond at the inhibitor's reactive site (Met48-Glu49) determined using time-course hydrolysis experiments; the same event was investigated for both subtilisin/WSCI and chymotrypsin/WSCI complexes using molecular dynamics simulations. The molecular details of the initial inhibitor-enzyme interactions, as well as of the changes observed during the simulations, allow us to speculate on the different fates of the two WSCI-proteinase complexes. |
| Databáze: | OpenAIRE |
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