In:
European Journal of Biochemistry, Wiley, Vol. 71, No. 2 ( 1976-12), p. 585-593
Abstract:
Membrane‐bound dd ‐carboxypeptidase of the unstable L‐form of Proteus mirabilis was solubilized by the non‐ionic detergent Genapol X‐100 and purified to protein homogeneity by affinity chromatography on ampicillin bound to succinyl‐aminododecyl‐cellulose. The purified enzyme with a molecular weight of 43000 is inhibited non‐competitively by penicillin G and carbenicillin, indicating a function of the penicillins as allosteric inhibitors. Sensitivity of the enzyme to penicillins is only moderate with a K i of 1 μM for penicillin G. Breakdown of the enzyme‐inhibitor complex EI with different penicillins occurs rapidly with reappearance of active dd ‐carboxypeptidase. The half‐life of EI with penicillin G is 5.5 min at 30 °C and 3.5 min at 37 °C, 10–1000‐fold shorter than EI half‐lives of dd ‐carboxypeptidases in several other bacteria. The low stability of the enzyme‐inhibitor complex and the moderate penicillin sensitivity appear to be the basis for the continued activity of dd ‐carboxypeptidase during growth of the L‐form and synthesis of peptidoglycan in the presence of high concentrations of penicillin.
Type of Medium:
Online Resource
ISSN:
0014-2956
,
1432-1033
DOI:
10.1111/ejb.1976.71.issue-2
DOI:
10.1111/j.1432-1033.1976.tb11149.x
Language:
English
Publisher:
Wiley
Publication Date:
1976
detail.hit.zdb_id:
1398347-7
detail.hit.zdb_id:
2172518-4
SSG:
12
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