A conserved glutamic acid bridge in serine carboxypeptidases, belonging to the alpha/beta hydrolase fold, acts as a pH-dependent protein-stabilizing element
| Autor: | Mortensen, U. H., Breddam, K. |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 1994 |
| Předmět: |
Protein Folding
Binding Sites Saccharomyces cerevisiae Proteins Base Sequence Molecular Sequence Data Cathepsin A Glutamic Acid Hydrogen Bonding Carboxypeptidases Saccharomyces cerevisiae Hydrogen-Ion Concentration Kinetics Glutamates Enzyme Stability Mutagenesis Site-Directed Amino Acid Sequence DNA Fungal Conserved Sequence Research Article |
| Popis: | Serine endopeptidases of the chymotrypsin family contain a salt bridge situated centrally within the active site, the acidic component of the salt bridge being adjacent to the catalytically essential serine. Serine carboxypeptidases also contain an acidic residue in this position but it interacts through a short hydrogen bond, probably of low-barrier type, with another acidic residue, hence forming a "glutamic acid bridge." In this study, the residues constituting this structural element in carboxypeptidase Y have been replaced by site-specific mutagenesis. It is demonstrated that the glutamic acid bridge contributes significantly to the stability of the enzyme below pH 6.5 and has an adverse effect at pH 9.5. Carboxypeptidase WII from wheat contains 2 such bridges, and it is more stable than carboxypeptidase Y at acidic pH. |
| Databáze: | OpenAIRE |
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