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Development of selective inhibitors against homoserine transacetylase ő a novel target for drug development (976.2)
Author(s) -
Thangavelu Bharani,
Pavlovsky Alexander,
Viola Ronald
Publication year - 2014
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.28.1_supplement.976.2
Subject(s) - homoserine , biochemistry , methionine , enzyme , bacteria , chemistry , biosynthesis , cofactor , amino acid , quorum sensing , biology , virulence , gene , genetics
Homoserine transacetylase (HTA) lies at a branch point in the aspartate metabolic pathway which leads to the biosynthesis of the essential amino acids methionine and lysine in plants, bacteria and fungi. The branch leading to the synthesis of methionine and the essential methyl transfer cofactor S‐adenosylmethionine (AdoMet) starts with the acetylation of homoserine to form O‐acetylhomoserine catalyzed by HTA. AdoMet is also the substrate for a group of enzymes that synthesize acylhomoserine lactones, virulence signaling molecules in Gram‐negative bacteria. Since the aspartate pathway is not found in humans, but is necessary for bacterial survival, the reaction catalyzed by HTA is a critical control point for cell growth and viability and is a potential target for the development of new antibiotics. We have cloned and purified homoserine transacetylases from the Gram‐positive bacteria Staphylococcus aureus, Gram‐negative bacteria Pseudomonas aeruginosa and fungi Candida albicans. A sensitive coupled‐enzyme activity assay had been developed to determine the kinetic properties of each enzyme form. A customized fragment library has been screened against these enzymes and initial hits have been identified with inhibition constants (Ki) values in the low millimolar range. Docking studies with published HTA structures are being used to guide the design and development of potent inhibitors. Initial crystallization of these new enzyme forms have produced diffraction quality crystals that are being optimized for data collection. The long term goal of this project is to develop drugs that selectively target this enzyme and block the methionine biosynthetic pathway. This work is supported by funding from the NIH (AI077720). Grant Funding Source : NIH (AI077720)