Brugia malayi (B. malayi) is one of the three causative agents of lymphatic filariasis, a neglected parasitic disease. Current literature suggests that dihydrofolate reductase is a potential drug target for the elimination of B. malayi. Here we report the recombinant expression and purification of a similar to 20 kDa B. malayi dihydrofolate reductase (BmDHFR). A His(6)-tagged construct was expressed in E. coli and purified by affinity chromatography to yield active and homogeneous enzyme for steady-state kinetic characterization and inhibition studies. The catalytic activity k(cat) was found to be 1.4 +/- 0.1 s(-1), the Michaelis Menten constant K-M for dihydrofolate 14.7 +/- 3.6 mu M, and the equilibrium dissociation constant K-D for NADPH 25 +/- 24 nM. For BmDHFR, IC50 values for a six DHFR inhibitors were determined to be 3.1 +/- 0.2 nM for methotrexate, 32 +/- 22 mu M for trimethoprim, 109 34 AM for pyrimethamine, 154 +/- 46 mu M for 2,4-diaminoquinazoline, 771 +/- 44 mu M for cycloguanil, and >20,000 mu M for 2,4-diaminopyrimidine. Our findings suggest that antifolate compounds can serve as inhibitors of BmDHFR. (C) 2016 Elsevier Inc. All rights reserved.