Bacterial resistance to beta-lactam antibiotics continues to become more prevalent and more clinically important. It is likely, however, that a large part of the resistance can be understood and investigated experimentally in terms of the chemistry of the interactions of beta- lactamases on one hand, which catalyse the hydrolysis of the antibodies, and the D-alanyl-D-alanine transpeptidase/-carboxypeptidases on the other, which catalyse the synthesis and maintenance of the peptide cross-links of bacterial cell walls, and which are inhibited by beta-lactam antibiotics. There is now good reason to believe that all of these beta-lactam binding sites have much in common. An understanding of the structure and function of these sites and of the relationship between them is fundamental to future antibiotics design -- both beta-lactam and otherwise. The object of the proposed research is to explore further the chemical functionality and the substrate binding properties of a series of these active sites, using a number of modified substrates, novel inhibitors, and potential effectors. In particular, a novel series of acyclic substrates and derived inhibitors will be employed. A mechanistic study of these sites, designed to determine the role of the functional groups present and the relationship between the mechanism of action of these enzymes and that of other more closely studied enzymes, e.g. serine proteinases, will also be commenced. These studies should lead to a more useful picture of beta-lactamase active sites, to a better idea as to their relationship to D-alanyl-D-alanine transpeptidase sites, and thus to new directions or antibiotic development.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI017986-10
Application #
3127597
Study Section
Physical Biochemistry Study Section (PB)
Project Start
1982-09-30
Project End
1995-08-31
Budget Start
1991-09-01
Budget End
1992-08-31
Support Year
10
Fiscal Year
1991
Total Cost
Indirect Cost
Name
Wesleyan University
Department
Type
Schools of Arts and Sciences
DUNS #
City
Middletown
State
CT
Country
United States
Zip Code
06459
Nemmara, Venkatesh V; Nicholas, Robert A; Pratt, R F (2016) Synthesis and Kinetic Analysis of Two Conformationally Restricted Peptide Substrates of Escherichia coli Penicillin-Binding Protein 5. Biochemistry 55:4065-76
Tilvawala, Ronak; Cammarata, Michael; Adediran, S A et al. (2015) A New Covalent Inhibitor of Class C ?-Lactamases Reveals Extended Active Site Specificity. Biochemistry 54:7375-84
Dzhekieva, Liudmila; Adediran, S A; Pratt, R F (2014) Interactions of ""bora-penicilloates"" with serine ?-lactamases and DD-peptidases. Biochemistry 53:6530-8
Dzhekieva, Liudmila; Adediran, S A; Herman, Raphael et al. (2013) Inhibition of DD-peptidases by a specific trifluoroketone: crystal structure of a complex with the Actinomadura R39 DD-peptidase. Biochemistry 52:2128-38
Tilvawala, Ronak; Pratt, R F (2013) Kinetics of action of a two-stage pro-inhibitor of serine ?-lactamases. Biochemistry 52:7060-70
Tilvawala, Ronak; Pratt, R F (2013) Covalent inhibition of serine ?-lactamases by novel hydroxamic acid derivatives. Biochemistry 52:3712-20
Nemmara, Venkatesh V; Adediran, S A; Dave, Kinjal et al. (2013) Dual substrate specificity of Bacillus subtilis PBP4a. Biochemistry 52:2627-37
Dzhekieva, Liudmila; Kumar, Ish; Pratt, R F (2012) Inhibition of bacterial DD-peptidases (penicillin-binding proteins) in membranes and in vivo by peptidoglycan-mimetic boronic acids. Biochemistry 51:2804-11
Adediran, S A; Lin, G; Pelto, R B et al. (2012) Crossover inhibition as an indicator of convergent evolution of enzyme mechanisms: a ?-lactamase and a N-terminal nucleophile hydrolase. FEBS Lett 586:4186-9
Pelto, Ryan B; Pratt, R F (2012) Kinetics and stereochemistry of hydrolysis of an N-(phenylacetyl)-*-hydroxyglycine ester catalyzed by serine *-lactamases and DD-peptidases. Org Biomol Chem 10:7356-62

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