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Substrate specificity of Escherichia coli LD‐carboxypeptidase on biosynthetically modified muropeptides
Author(s) -
Leguina José Ignacio,
Quintela José Carlos,
de Pedro Miguel A.
Publication year - 1994
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(94)80425-7
Subject(s) - escherichia coli , chemistry , substrate specificity , biochemistry , carboxypeptidase , microbiology and biotechnology , enzyme , biology , gene
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.