[51] Exocellular dd-carboxypeptidases-transpeptidases from Streptomyces

Strains R39 and R61 are soil isolates. Their designations are arbitrary. In strain R39, the cross-link between the peptide units of the wall peptidoglycan extends from the C-terminal D-alanine of one unit to the amino group at the D-center of meso-diaminopimelic acid of another unit (peptidoglycan of chemotype I). The interpeptide bond is in position to a free carboxyl group. In strain R61, the cross-link extends from a C-terminal D-alanine of a peptide unit to a glycine residue attached to the amino group of LL-diaminopimelic acid of another peptide unit (peptidoglycan of chemotype II). The exocellular DD carboxypeptidases-transpeptidases produced by both strains catalyze hydrolysis, react with β-lactam antibiotics. This chapter explains the assay methods for DD-Carboxypeptidase activity like the standard reaction, chemical estimation of free Alanine, as well as, assay method for β-Lactamase. It also discusses the Excretion of DD-Carboxypeptidase-Transpeptidase and β -Lactamase by Streptomyces R39, Excretion of DD-Carboxypeptidase-Transpeptidase and β-Lactamase by Streptomyces R61, purification of the DD-Carboxypeptidase-Transpeptidase from Streptomyces R39 (for 500 Liters of Culture Fluid), Purification of the DD-Carboxypeptidase-Transpeptidase from Streptomyces R61 (for 400 Liters of Culture Fluid), Physicochemical Properties of DD-Carboxypeptidases-Transpeptidases from Streptomyces R39 and R61, Interaction between DD-Carboxypeptidases-Transpeptidases from Streptomyces R39 and R61 and β-Lactam Antibiotics , Titration of DD-Carboxypeptidases-Transpeptidases from Streptornyces R39 and R61 by β-Lactam Antibiotics, Hydrolysis Reactions Catalyzed by the DD-Carboxypeptidases-Transpeptidases from Streptomyces R39 and R61, Concomitant Hydrolysis and Transfer Reactions Involving Distinct Donor and Acceptor Peptides, Catalyzed by the DD-Carboxypeptidases-Transpeptidases from Streptonayces R39 and R61, Concomitant Hydrolysis and Transfer Reactions Catalyzed by the DD-Carboxypeptidases-Transpeptidases from Streptomyces R39 and R61 and in Which the Same Peptide Acts as Donor and Acceptor and Inhibition of DD-Carboxypeptidases-Transpeptidases from Streptomyces R39 and R61 by β-Lactam Antibiotics in the Presence of Substrates.
Copyright © 1976 Published by Elsevier Inc.