Heterologous expression and biochemical characterization of recombinant alpha phosphoglucomutase from Mycobacterium tuberculosis H37Rv.

Gagan Chhabra, Divya Mathur, Aparna Dixit, Lalit C Garg

Gene Regulation Laboratory, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, India.

Protein expression and purification 2012 Sep

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Phosphoglucomutase (PGM) plays an important role in polysaccharide capsule formation and virulence in a number of bacterial pathogens. However, the enzyme has not yet been characterized from Mycobacterium tuberculosis (Mtb). Here, we report the biochemical properties of recombinant Mtb-PGM as well as the in silico structural analysis from Mtb H37Rv. The purified recombinant enzyme was enzymatically active with a specific activity of 67.5 U/mg and experimental k(cat) of 70.31 s(-1) for the substrate glucose-1-phosphate. The enzyme was stable in pH range 6.5-7.4 and exhibited temperature optima range between 30 and 40°C. Various kinetic parameters and constants of the rPGM were determined. A structural comparison of Modeller generated 3D Mtb-PGM structure with rabbit muscle PGM revealed that the two enzymes share the same overall heart shape and four-domain architecture, despite having only 17% sequence identity. However, certain interesting differences between the two have been identified, which provide an opportunity for designing new drugs to specifically target the Mtb-PGM. Also, in the absence of the crystal structure of the Mtb-PGM, the modeled structure could be further explored for in silico docking studies with suitable inhibitors. Copyright © 2012 Elsevier Inc. All rights reserved.

Citation

Gagan Chhabra, Divya Mathur, Aparna Dixit, Lalit C Garg. Heterologous expression and biochemical characterization of recombinant alpha phosphoglucomutase from Mycobacterium tuberculosis H37Rv. Protein expression and purification. 2012 Sep;85(1):117-24