Purification and characterization of some enzymatic properties of neuraminidase from Corynebacterium ulcerans.

Neuraminidase of Corynebacterium-ulcerans was purified by affinity chromatography using immobilized colominic acid preparations. Neuraminidase appears to be a thermolabile protein, molecular mass 70 000 Da. The pH optimum of 5.5 is independent of the substrate used; the optimal temperature is 37 degrees C, the Michaelis constant towards N-acetylneuraminosyllactose is 5.2 X 10(-4) M. Ca2+ and Ba2+ activated the enzyme, but Zn2+, Fe2+, and chelating agent EDTA were inhibitory. In our experiments the enzyme did not hydrolyse the (alpha - 2.6) or (alpha - 2.8) bonds of submaxillary pig mucin and colominic acid, respectively, but it hydrolysed such substrates as fetuin, ovomucin, orosomucoid and horse serum glycoproteins.