A novel capillary electrophoresis-based assay method for coenzyme B6-dependent diaminopimelate decarboxylase from Propionibacterium acnes

Abstract

In bacteria, diaminopimelate decarboxylase is responsible for L-lysine biosynthesis, and may become a potential drug target for treatment of multidrug resistant bacteria. A gene encoding diaminopimelate decarboxylase was cloned from Propionibacterium acnes ATCC 6922 and was over-expressed in E. coli. Without the use of radioactive labeled compound as substrate, a capillary electrophoresis-based enzyme assay method was reported in this study. The enzyme follows Michaelis–Menten kinetics with a k_cat of 2.2 s⁻¹. The apparent K_m for diaminopimelate and pyridoxal-5′-phosphate is 1.6 ± 0.3 mM and 1.3 ± 0.1 μM, respectively. This assay method can be automated with an auto-sampler, which will become a cheaper alternative for large-scale screening.