Parasitology

Research Article

Molecular cloning and characterization of glucose-6-phosphate dehydrogenase from Brugia malayi

ANITA VERMAa1, MANISH K. SUTHARa1, PAWAN K. DOHAREYa1, SMITA GUPTAa1, SUNITA YADAVa1, PREM M. S. CHAUHANa2 and JITENDRA K. SAXENAa1 c1

a1 Division of Biochemistry, CSIR-Central Drug Research Institute, Lucknow-226001, Uttar Pradesh, India

a2 Division of Medicinal and Process Chemistry, CSIR-Central Drug Research Institute, Lucknow-226001, Uttar Pradesh, India

SUMMARY

Glucose-6-phosphate dehydrogenase (G6PD), a regulatory enzyme of the pentose phosphate pathway from Brugia malayi, was cloned, expressed and biochemically characterized. The Km values for glucose-6-phosphate and nicotinamide adenine dinucleotide phosphate (NADP) were 0·25 and 0·014 mm respectively. The rBmG6PD exhibited an optimum pH of 8·5 and temperature, 40 °C. Adenosine 5′ [γ-thio] triphosphate (ATP-γ-S), adenosine 5′ [β,γ-imido] triphosphate (ATP-β,γ-NH), adenosine 5′ [β-thio] diphosphate (ADP-β-S), Na+, K+, Li+ and Cu++ ions were found to be strong inhibitors of rBmG6PD. The rBmG6PD, a tetramer with subunit molecular weight of 75 kDa contains 0·02 mol of SH group per mol of monomer. Blocking the SH group with SH-inhibitors, led to activation of rBmG6PD activity by N-ethylmaleimide. CD analysis indicated that rBmG6PD is composed of 37% α-helices and 26% β-sheets. The unfolding equilibrium of rBmG6PD with GdmCl/urea showed the triphasic unfolding pattern along with the highly stable intermediate obtained by GdmCl.

(Received October 26 2012)

(Revised December 21 2012)

(Revised January 10 2013)

(Accepted January 21 2013)

(Online publication March 18 2013)

Key words

  • Brugia malayi ;
  • glucose-6-phosphate dehydrogenase;
  • DHEA;
  • inhibitors;
  • circular dichroism;
  • GdmCl;
  • urea;
  • drug target

Correspondence

c1 Corresponding author: Division of Biochemistry, CSIR-Central Drug Research Institute, Lucknow-226001, Uttar Pradesh, India. E-mail: jkscdri@yahoo.com

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