Inhibition of Streptomyces griseus aminopeptidase and effects of calcium ions on catalysis and binding--comparisons with the homologous enzyme Aeromonas proteolytica aminopeptidase.
Eur J Biochem
; 258(2): 313-9, 1998 Dec 01.
Article
in En
| MEDLINE
| ID: mdl-9874195
ABSTRACT
Streptomyces griseus aminopeptidase is a zinc metalloenzyme containing 2 mol zinc/mol protein, similar to the homologous enzyme Aeromonas proteolytica aminopeptidase. In addition, a unique Ca2+-binding site has been identified in the Streptomyces enzyme, which is absent in the Aeromonas enzyme. Binding of Ca2+ enhances stability of the Streptomyces enzyme and modulates its activity and affinity towards substrates and inhibitors in a structure-dependent manner. Among the three hydrophobic 4-nitroanilides of alanine, valine and leucine, the latter displays the largest overall activation (increase in k(cat)/Km). Large enhancements in affinity (1/Ki) upon Ca2+ binding have been observed for inhibitors with flexible (leucine-like) residues at their N-termini and smaller enhancements for inhibitors with rigid (phenylalanine-like) residues.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Peptides
/
Streptomyces griseus
/
Calcium
/
Aeromonas
/
Aminopeptidases
Type of study:
Prognostic_studies
Language:
En
Journal:
Eur J Biochem
Year:
1998
Document type:
Article
Affiliation country:
Israel