Crystallization of and preliminary crystallographic data for allosteric L-lactate dehydrogenase from Bifidobacterium longum.

ABSTRACT

L-Lactate dehydrogenase from Bifidobacterium longum aM101-2 was overexpressed in Escherichia coli and then purified. The enzyme was crystallized from a polyethylene glycol 6000 solution by the hanging drop vapor diffusion method. Crystals grown in the presence of NADH (type II), both NADH and oxamate (type III), and NADH, oxamate, and FBP (type IV) were analyzed. All three crystal forms belong to the orthorhombic system, space group P2(1)2(1)2. The cell dimensions of the type II crystals were a = 106.2 A, b = 131.6 A, and c = 63.8 A. Those of the type III and type IV crystals were a = 106.4 A, b = 131.4 A, and c = 63.8 A. The type III crystals diffract X-rays to beyond 2.5 A spacing. The type II and type III crystals were stable as to X-ray irradiation.