4Q8I

Crystal Structure of beta-lactamase from M.tuberculosis covalently complexed with Tebipenem

Summary for 4Q8I

• Entry DOI: 10.2210/pdb4q8i/pdb
• Related: 4QB8
• Descriptor: Beta-lactamase, (4R,5S)-3-(1-(4,5-dihydrothiazol-2-yl)azetidin-3-ylthio)-5-((2S,3R)-3-hydroxy-1-oxobutan-2-yl)-4-methyl-4,5- dihydro-1H-pyrrole-2-carboxylic acid, PHOSPHATE ION, ... (4 entities in total)
• Functional Keywords: betalactam, betalactamase, carbapenem, tebipenem, tebipenem pivoxil, 3-layer sandwich, dd-peptidase/beta-lactamase superfamily, hydrolase-antibiotic complex, hydrolase/antibiotic
• Biological source: Mycobacterium tuberculosis
• Cellular location: Cell membrane; Lipid-anchor (Potential): P9WKD3
• Total number of polymer chains: 1
• Total formula weight: 29166.24

Authors

Hazra, S.,Blanchard, J. (deposition date: 2014-04-27, release date: 2014-08-20, Last modification date: 2024-10-16)

Primary citation

Hazra, S.,Xu, H.,Blanchard, J.S.
Tebipenem, a new carbapenem antibiotic, is a slow substrate that inhibits the beta-lactamase from Mycobacterium tuberculosis.
Biochemistry, 53:3671-3678, 2014

PubMed Abstract: The genome of Mycobacterium tuberculosis contains a gene, blaC, which encodes a highly active β-lactamase (BlaC). We have previously shown that BlaC has an extremely broad spectrum of activity against penicillins and cephalosporins but weak activity against newer carbapenems. We have shown that carbapenems such as meropenem, doripenem, and ertapenem react with the enzyme to form enzyme-drug covalent complexes that are hydrolyzed extremely slowly. In the current study, we have determined apparent Km and kcat values of 0.8 μM and 0.03 min(-1), respectively, for tebipenem, a novel carbapenem whose prodrug form, the pivalyl ester, is orally available. Tebipenem exhibits slow tight-binding inhibition at low micromolar concentrations versus the chromogenic substrate nitrocefin. FT-ICR mass spectrometry demonstrated that the tebipenem acyl-enzyme complex remains stable for greater than 90 min and exists as mixture of the covalently bound drug and the bound retro-aldol cleavage product. We have also determined the high-resolution crystal structures of the BlaC-tebipenem covalent acylated adduct (1.9 Å) with wild-type BlaC and the BlaC-tebipenem Michaelis-Menten complex (1.75 Å) with the K73A BlaC variant. These structures are compared to each other and to other carbapenem-BlaC structures.

PubMed: 24846409
DOI: 10.1021/bi500339j

Experimental method

X-RAY DIFFRACTION (1.901 Å)