Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019693 (HIV)
 170,526 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tuberculosis (TB) resurged in the late 1980s and an estimated 1.87 million people died of TB in 1997. The reemergence of tuberculosis as a public health threat, the high susceptibility of HIV-infected persons, and the proliferation of multidrug-resistant strains have created a need to develop new antimycobacterial agents. The existence of a shikimate pathway has been predicted by the determination of the genome sequence of Mycobacterium tuberculosis. The M. tuberculosis aroK-encoded shikimate kinase and aroA-encoded 5-enolpyruvylshikimate 3-phosphate (EPSP) synthase were cloned and the enzymes overexpressed in soluble form. Overexpression was achieved without isopropyl beta-d-thiogalactoside induction, and cells grown to stationary phase yielded approximately 30% of target proteins to total soluble cell proteins. Enzyme activity measurements using coupled assays demonstrated that there was a 328-fold increase in specific activity for shikimate kinase and 101-fold increase for EPSP synthase.
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PMID:Cloning and overexpression in soluble form of functional shikimate kinase and 5-enolpyruvylshikimate 3-phosphate synthase enzymes from Mycobacterium tuberculosis. 1148 5

Currently, there are 8 million new cases and 2 million deaths annually from tuberculosis, and it is expected that a total of 225 million new cases and 79 million deaths will occur between 1998 and 2030. The reemergence of tuberculosis as a public health threat, the high susceptibility of HIV-infected persons, and the proliferation of multi-drug-resistant strains have created a need to develop new antimycobacterial agents. The existence of homologues to the shikimate pathway enzymes has been predicted by the determination of the genome sequence of Mycobacterium tuberculosis. We have previously reported the cloning and overexpression of M. tuberculosis aroA-encoded EPSP synthase in both soluble and active forms, without IPTG induction. Here, we describe the purification of M. tuberculosis EPSP synthase (mtEPSPS) expressed in Escherichia coli BL21(DE3) host cells. Purification of mtEPSPS was achieved by a one-step purification protocol using an anion exchange column. The activity of the homogeneous enzyme was measured by a coupled assay using purified shikimate kinase and purine nucleoside phosphorylase proteins. A total of 53 mg of homogeneous enzyme could be obtained from 1L of LB cell culture, with a specific activity value of approximately 18 Umg(-1). The results presented here provide protein in quantities necessary for structural and kinetic studies, which are currently underway in our laboratory.
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PMID:One-step purification of 5-enolpyruvylshikimate-3-phosphate synthase enzyme from Mycobacterium tuberculosis. 1269 93

Tuberculosis made a resurgence in the mid-1980s and now kills approximately 3 million people a year. The re-emergence of tuberculosis as a public health threat, the high susceptibility of HIV-infected persons and the proliferation of multi-drug-resistant strains have created a need to develop new drugs. Shikimate kinase and other enzymes in the shikimate pathway are attractive targets for development of non-toxic antimicrobial agents, herbicides and anti-parasitic drugs, because the pathway is essential in these species whereas it is absent from mammals. The crystal structure of shikimate kinase from Mycobacterium tuberculosis (MtSK) complexed with MgADP and shikimic acid (shikimate) has been determined at 2.3 A resolution, clearly revealing the amino-acid residues involved in shikimate binding. This is the first three-dimensional structure of shikimate kinase complexed with shikimate. In MtSK, the Glu61 residue that is strictly conserved in shikimate kinases forms a hydrogen bond and salt bridge with Arg58 and assists in positioning the guanidinium group of Arg58 for shikimate binding. The carboxyl group of shikimate interacts with Arg58, Gly81 and Arg136 and the hydroxyl groups interact with Asp34 and Gly80. The crystal structure of MtSK-MgADP-shikimate will provide crucial information for the elucidation of the mechanism of the shikimate kinase-catalyzed reaction and for the development of a new generation of drugs against tuberculosis.
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PMID:Structure of shikimate kinase from Mycobacterium tuberculosis reveals the binding of shikimic acid. 1558 79

Tuberculosis remains one of the most dreaded infectious diseases notwithstanding the availability of a number of anti-tuberculosis drugs. The recent rise of multidrug-resistant tuberculosis and its association with HIV infection poses a challenging health concern. Therefore, there exists a pressing requirement to identify novel drug targets and develop new anti-tuberculosis drugs that will be effective against multidrug-resistant-tuberculosis. Shikimate kinase is a novel and attractive drug target as it is vital for the survival of Mycobacterium tuberculosis but is absent in mammals. Hence, inhibitors designed against shikimate kinase will be specific to the pathogen and be least harmful to the host. Till date, no drug candidates are available against this target. The crystal structure of Mycobacterium tuberculosis shikimate kinase complexed with shikimate has been used to identify a dipeptide inhibitor using in silico structure-based design approach. The designed peptidic inhibitor has a predicted binding affinity of 5.5 nm which is 8000 times better than substrate shikimate and 10 times greater than the best suggested inhibitor. It is potent in both the known open and closed LID conformations of target protein. As small peptides are known to be non-toxic, this inhibitor could be a lead compound for development of specific anti-tuberculosis drugs.
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PMID:Structure-based in silico design of a high-affinity dipeptide inhibitor for novel protein drug target Shikimate kinase of Mycobacterium tuberculosis. 2062 8