Evaluating the activity of bacterial enzyme DXP synthase a potential target for newer antibiotics

Abstract

An emerging medical crisis involving the development of antibiotic resistant bacteria in the human body is compromising treatment of infections, leaving patients in critical condition. Infections that are becoming unresponsive to current treatment are creating a need for new antibiotics. In order to develop new antibiotics, researchers need to identify new targets that have high specificity for certain bacterial pathways. The enzyme D‐xylulose 5‐phosphate (DXP) synthase catalyzes the first step in the MEP (methylerythritol phosphate) pathway in human pathogens, which produces the biological molecules necessary to regulate numerous cellular functions, including central metabolism. Inhibition of DXP synthase would prevent or heavily reduce the rate of DXP production, which can then prevent or delay the continuation of the MEP pathway and thus is an ideal candidate for antibiotic development. In order to test the effectiveness of potential inhibitors of DXP synthase it is first necessary to establish a system to monitor the activity of DXP. We have purified Histidine tagged versions of DXP synthase and 1‐Deoxy‐D‐Xylulose 5‐Phosphate Reductoisomerase (IspC). The activity of DXP synthase cannot be directly measured using spectroscopic techniques, however it can be coupled to the activity of IspC, which in the process of converting DXP into MEP oxidizes NADPH. The establishment of this in vitro system will enable us to test the efficacy of novel inhibitors of DXP that are currently being developed.Support or Funding InformationSupported by internal grants from St. John Fisher College School of the Arts and Wegmans school of Pharmacy