Kinetic studies examining the inhibitory potential of compounds selected using a computationally derived active site model of glutamate racemase from S. Pneumoniae

Abstract

Antibiotic resistance is continually developing and diminishing the efficacy of current antibiotics and exploring novel targets is essential. Glutamate racemase, the enzyme responsible for the inter‐conversion between D‐ and L‐glutamate in bacteria, is a potential target. Glutamate racemase is essential for viability of several pathogens, making it an ideal target for developing a new class of antibiotics. Comparative modeling was employed to develop a three‐dimensional structure for the S. Pneumoniae glutamate racemase using Prime®. Several inhibitors were docked into the model's active site to investigate their binding modes. Our results indicate that inhibitor binding induces active site structural changles and that two active site water molecules are important for proper orientation. Our lab has synthesized and expressed the gene MurI, which encodes glutamate racemase. We have explored the inhibition potential of several compounds and present here the kinetic analysis. Inhibitor and substrate was reacted with glutamate racemase, followed by heat inactivation and subsequent reaction of L‐glutamate product with glutamate dehydrogenase. We were able to determine the inhibitory potential of the most promising compounds and compare them to the results obtained in whole cell assays.