Overexpression and enzymatic characterization of Neisseria gonorrhoeae penicillin-binding protein 4.

The penicillin-binding proteins (PBPs) are ubiquitous bacterial enzymes involved in cell wall biosynthesis, and are the targets of the beta-lactam antibiotics. The low molecular mass Neisseria gonorrhoeae PBP 4 (NG PBP 4) is the fourth PBP revealed in the gonococcal genome. NG PBP 4 was cloned, overexpressed, purified, and characterized for beta-lactam binding, DD-carboxypeptidase activity, acyl-donor substrate specificity, transpeptidase activity, inhibition by a number of active site directed reagents, and pH profile.

Neisseria gonorrhoeae penicillin-binding protein 3 exhibits exceptionally high carboxypeptidase and beta-lactam binding activities.

A soluble form of penicillin-binding protein 3 (PBP 3) from Neisseria gonorrhoeae was expressed and purified from Escherichia coli and characterized for its interaction with beta-lactam antibiotics, its catalytic properties with peptide and peptidoglycan substrates, and its role in cell viability and morphology. PBP 3 had an unusually high k(2)/K' value relative to other PBPs for acylation with penicillin (7.7 x 10(5) M(-1) s(-1)) at pH 8.

Potential transition state analogue inhibitors for the penicillin-binding proteins.

Penicillin-binding proteins (PBPs) are ubiquitous bacterial enzymes involved in cell wall biosynthesis. The development of new PBP inhibitors is a potentially viable strategy for developing new antibacterial agents. Several potential transition state analogue inhibitors for the PBPs were synthesized, including peptide chloromethyl ketones, trifluoromethyl ketones, aldehydes, and boronic acids.

pH, inhibitor, and substrate specificity studies on Escherichia coli penicillin-binding protein 5.

The recent structural determination of Escherichia coli penicillin-binding protein 5 (PBP 5) provides the opportunity for detailed structure-function studies of this enzyme. PBP 5 was investigated in terms of its stability, linear reaction kinetics, acyl-donor substrate specificity, inhibition by a number of active site-directed reagents, and pH profile. PBP 5 demonstrated linear reaction kinetics for up to several hours.