Specificity and reversibility of the transpeptidation reaction catalyzed by the Streptomyces R61 D-Ala-D-Ala peptidase.
Protein Sci
; 14(11): 2922-8, 2005 Nov.
Article
em En
| MEDLINE
| ID: mdl-16199665
ABSTRACT
The specificity of the Streptomyces R61 penicillin-sensitive D-Ala-D-Ala peptidase has been re-examined with the help of synthetic substrates. The products of the transpeptidation reactions obtained with Gly-L-Xaa dipeptides as acceptor substrates are themselves poor substrates of the enzyme. This is in apparent contradiction with the classically accepted specificity rules for D-Ala-D-Ala peptidases. The Gly-L-Xaa dipeptide is regenerated by both the hydrolysis and transpeptidation reactions. The latter reaction is observed when another Gly-L-Xaa peptide or D-Alanine are supplied as acceptors. Utilization of substrates in which the terminal -COO(-) group has been esterified or amidated shows that a free carboxylate is not an absolute prerequisite for activity. The results are discussed in the context of the expected reversibility of the transpeptidation reaction.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Streptomyces
/
D-Ala-D-Ala Carboxipeptidase Tipo Serina
Idioma:
En
Revista:
Protein Sci
Assunto da revista:
BIOQUIMICA
Ano de publicação:
2005
Tipo de documento:
Article
País de afiliação:
Bélgica