KDN-cleaving sialidase isolated from hepatopancreas of mollusks

Abstract

A sialidase capable of cleaving a glycoconjugate to yield 3-deoxy-D-glycero-D-galacto-2-nonulosonic acid (KDN) is isolated from hepatopancreas of mollusks. Preferably, the sialidase is isolated by processing crude oyster hepatopancreas to form a crude extract of the sialidase enzyme. The crude enzyme is further concentrated and refined utilizing sequential column chromatography fractogel EMD DEAE-650 (M), sephacryl S-200, and fractogel EMD SP 650 (M) chromatography, respectively. Using this procedure, the sialidase is purified over 155 fold with a 17% recovery. Ferric ion exerts a three fold stimulation in the activity of the sialidase, at a concentration of 3 mM. The sialidase cleaves 4-methylumbelliferyl-KDN, KDN.alpha.2.fwdarw.3Gal.beta.1.fwdarw.4GlcCer, KDN.alpha.2.fwdarw.6Gal.beta.1.fwdarw.4GlcCer, or KDN.alpha.2.fwdarw.6GalNAc-o1 to yield KDN.

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