Acyltransferase activities of the high-molecular-mass essential penicillin-binding proteins

Abstract

The high-molecular-mass penicillin-binding proteins (HMM-PBPs), present in the cytoplasmic membranes of all eubacteria, are involved in important physiological events such as cell elongation, septation or shape determination. Up to now it has, however, been very difficult or impossible to study the catalytic properties of the HMM-PBPs in vitro. With simple substrates, we could demonstrate that several of these proteins could catalyse the hydrolysis of some thioesters or the transfer of their acyl moiety on the amino group of a suitable acceptor nucleophile. Many of the acyl-donor substrates were hippuric acid or benzoyl-D-alanine derivatives, and their spectroscopic properties enabled a direct monitoring of the enzymic reaction. In their presence, the binding of radioactive penicillin to the PBPs was also inhibited.

Characterization of the Bifunctional Glycosyltransferase/Acyltransferase Penicillin-Binding Protein 4 of Listeria monocytogenes

“…Unlabeled ␤-lactam antibiotics were from Sigma. Benzoyl-Gly-thiolactate (Bz-Gly-Thl), benzoyl-Gly-thiolglycolate (BzGly-Thg), benzoyl-D-Ala-thiolglycolate (Bz-D-Ala-Thg), and Ac 2 -L-Lys-D-Ala-D-Ala, were described previously (1). The meso-[…”

TheponAGene ofEnterococcus faecalisJH2-2 Codes for a Low-Affinity Class A Penicillin-Binding Protein

“…(i) DDPeptidase/esterase activity. Interactions with thiolester substrates such as benzoyl-Gly-thioglycolate and benzoyl-D-Alathioglycolate were studied as described previously (1,18,30). Hydrolysis of thiolester substrates (⌬ε ϭ Ϫ2,000 M Ϫ1 cm Ϫ1 ) by His*PBP1 (0.1 M) was monitored over a 10-min period by measuring variations in absorbance at 250 nm on an UVIKON 860 apparatus (BRS, Ruisbroek, Belgium) coupled to a microcomputer via an RJ322 interface (23).…”

N-acetyl-3,4-dihydroxy-L-phenylalanine, a second identified bioactive metabolite produced by Streptomyces sp. 8812

“…Under the procedures described previously, [10][11][12] the inhibitory effect of DD-carboxypeptidases activity was measured. Thioester C 6 H 5 -CO-NH-(D)CH(CH 3 )-CO-S-CH 2 -COOH was used as a substrate 10,12 (Supplementary Bioassay).…”

“…Thioester C 6 H 5 -CO-NH-(D)CH(CH 3 )-CO-S-CH 2 -COOH was used as a substrate 10,12 (Supplementary Bioassay). JS-2 and structurally related compounds, 3,4-dihydroxy-L-phenylalanine (Sigma, St Louis, MO, USA), 3,4-dihydroxy-D-phenylalanine (Sigma) and N-acetyl-3,4-dihydroxy-D-phenylalanine (synthesized analogously as L-form) were examined.…”