| Literature DB >> 28164792 |
Chunyan Li1, Qiming Li1, Yuan Zhang1, Zhen Gong1, Sai Ren1, Ping Li1, Jianping Xie2.
Abstract
Lipids and lipases/esterases are essential for Mycobacterium tuberculosis (Mtb) survival and persistence, even virulence. Mycobacterium tuberculosis H37Rv Rv1076 (LipU), a member of lipase family, is homologous to the human Hormone Sensitive Lipase (HSL) based on the presence of conserved motif 'GXSXG'. To define the enzymatic characteristics of rv1076, the gene was cloned, and expressed in Escherichia coli. The protein was purified for enzymatic characterization. LipU showed high specific activity for the hydrolysis of short carbon chain substrates with optimal activity at 40°C/pH 8.0 and stability at low temperature and near-neutral pH. The specific activity, Km and Vmax of LipU was calculated to 176.7U/mg, 1.73μM and 62.24μM/min respectively. Ionic detergents can inhibit its activity. The active-site residues of LipU were determined to be Ser140, Asp244 and His269 by site-directed mutagenesis. The upregulation of Mycobacterium tuberculosis rv1076 under nutritive stress implicates a role in starvation.Entities:
Keywords: Characteristics; Lipases/esterases; Mycobacterium tuberculosis; Rv1076; lipU
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Year: 2016 PMID: 28164792 DOI: 10.1016/j.micres.2016.12.005
Source DB: PubMed Journal: Microbiol Res ISSN: 0944-5013 Impact factor: 5.415