Substrate specificity of Escherichia coli LD‐carboxypeptidase on biosynthetically modified muropeptides

FEBS Letters

de Pedro, Miguel A.¹  Leguina, José Ignacio¹  Quintela, José Carlos¹ 

[1] Centra de Biologia Molecular ‘Severo Ochoa’ CSIC-UAM, Facultad de Ciencias UAM, Campus de Cantoblanco, 28049 Madrid, Spain

关键词: Escherichia coli;    Carboxypeptidase;    Murein;    Peptidoglycan;    d-Amino acid;   

DOI  :  10.1016/0014-5793(94)80425-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Escherichia coli murein can be biosynthetically modified. Amino acids at positions 3 and 4 (m-diaminopimelic acid and D-alanine, respectively) on the peptide moieties can be changed under appropriate growth conditions. The activity of E. coli LD-carboxypeptidase on biosynthetically modified substrates has been studied in vitro. The enzyme hydrolysed all tested disaccharide-tetrapeptide monomeric muropeptides modified at position 4. Monomers with m-lanthionine, but not with L-ornithine, instead of m-diaminopimelic acid at position 3 were accepted. However, neither cross-linked muropeptides nor macromolecular murein were substrates for the reaction. Our observations argue against a direct effect of ld-carboxypeptidase on macromolecular murein metabolism.

【 授权许可】

Unknown