Download MendeleyMechanism-based inactivator of isocitrate lyases 1 and 2 from Mycobacterium tuberculosis.
Pham, T.V., Murkin, A.S., Moynihan, M.M., Harris, L., Tyler, P.C., Shetty, N., Sacchettini, J.C., Huang, H.L., Meek, T.D.(2017) Proc Natl Acad Sci U S A 114: 7617-7622
- PubMed: 28679637
- DOI: https://doi.org/10.1073/pnas.1706134114
- Primary Citation of Related Structures:
5DQL - PubMed Abstract:
Isocitrate lyase (ICL, types 1 and 2) is the first enzyme of the glyoxylate shunt, an essential pathway for Mycobacterium tuberculosis ( Mtb ) during the persistent phase of human TB infection. Here, we report 2-vinyl-d-isocitrate (2-VIC) as a mechanism-based inactivator of Mtb ICL1 and ICL2. The enzyme-catalyzed retro-aldol cleavage of 2-VIC unmasks a Michael substrate, 2-vinylglyoxylate, which then forms a slowly reversible, covalent adduct with the thiolate form of active-site Cys 191 2-VIC displayed kinetic properties consistent with covalent, mechanism-based inactivation of ICL1 and ICL2 with high efficiency (partition ratio, <1). Analysis of a complex of ICL1:2-VIC by electrospray ionization mass spectrometry and X-ray crystallography confirmed the formation of the predicted covalent S -homopyruvoyl adduct of the active-site Cys 191 .
Organizational Affiliation:
Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843.
