title: Insights into the structure-function relationship of Brugia malayi thymidylate kinase (BmTMK).
abstract: Lymphatic filariasis is a debilitating disease caused by lymph dwelling nematodal parasites like Wuchereria bancrofti, Brugia malayi and Brugia timori. Thymidylate kinase of B. malayi is a key enzyme in the de novo and salvage pathways for thymidine 5'-triphosphate (dTTP) synthesis. Therefore, B. malayi thymidylate kinase (BmTMK) is an essential enzyme for DNA biosynthesis and an important drug target to rein in filariasis. In the present study, the structural and functional changes associated with recombinant BmTMK, in the presence of protein denaturant GdnHCl, urea and pH were studied. GdnHCl and urea induced unfolding of BmTMK is non-cooperative and influence the functional property of the enzyme much lower than their Cm values. The study delineate that BmTMK is more prone to ionic perturbation. The dimeric assembly of BmTMK is an absolute requirement for enzymatic acitivity and any subtle change in dimeric conformation due to denaturation leads to loss of enzymatic activity. The pH induced changes on structure and activity suggests that selective modification of active site microenvironment pertains to difference in activity profile. This study also envisages that chemical moieties which acts by modulating oligomeric assembly, could be used for better designing of inhibitors against BmTMK enzyme.
authors.affiliation: Biochemistry Division, CSIR-Central Drug Research Institute, (CSIR-CDRI), BS-10/1, Sector 10, Jankipuram Extension, Sitapur Road, P. O. Box 173, Lucknow 226031, India.
authors.forename: Pawan Kumar
authors.initials: PK
authors.lastname: Doharey
authors.affiliation: Molecular & Structural Biology Division, CSIR-Central Drug Research Institute, (CSIR-CDRI), BS-10/1, Sector 10, Jankipuram Extension, Sitapur Road, P. O. Box 173, Lucknow 226031, India.
authors.forename: Sudhir Kumar
authors.initials: SK
authors.lastname: Singh
authors.affiliation: Biochemistry Division, CSIR-Central Drug Research Institute, (CSIR-CDRI), BS-10/1, Sector 10, Jankipuram Extension, Sitapur Road, P. O. Box 173, Lucknow 226031, India.
authors.forename: Pravesh
authors.initials: P
authors.lastname: Verma
authors.affiliation: Biochemistry Division, CSIR-Central Drug Research Institute, (CSIR-CDRI), BS-10/1, Sector 10, Jankipuram Extension, Sitapur Road, P. O. Box 173, Lucknow 226031, India.
authors.forename: Anita
authors.initials: A
authors.lastname: Verma
authors.affiliation: Department of Biochemistry, Banaras Hindu University, Varanasi 221005, India.
authors.forename: Sushma
authors.initials: S
authors.lastname: Rathaur
authors.affiliation: Biochemistry Division, CSIR-Central Drug Research Institute, (CSIR-CDRI), BS-10/1, Sector 10, Jankipuram Extension, Sitapur Road, P. O. Box 173, Lucknow 226031, India. Electronic address: jkscdri@yahoo.com.
authors.forename: Jitendra Kumar
authors.initials: JK
authors.lastname: Saxena
mesh_terms: D000818:Animals; D017178:Brugia malayi / Q000201:enzymology* / Q000472:pathogenicity; D020134:Catalytic Domain; D019281:Dimerization; D004605:Elephantiasis, Filarial / Q000188:drug therapy / Q000201:enzymology* / Q000469:parasitology; D006801:Humans; D009703:Nucleoside-Phosphate Kinase / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry* / Q000235:genetics; D013329:Structure-Activity Relationship; D013942:Thymine Nucleotides / Q000737:chemistry
chemical_list: D011994:Recombinant Proteins; D013942:Thymine Nucleotides; D009703:Nucleoside-Phosphate Kinase; C020093:dTMP kinase; C024157:thymidine 5'-triphosphate
keywords: Brugia malayi; Drug target; Inhibition; Refolding; Thymidylate kinase; Unfolding