Schauer R, Wember M, Tschesche H. Isolation and characterization of an oligosaccharide- and glycoprotein-specific sialidase from human leucocytes.
HOPPE-SEYLER'S ZEITSCHRIFT FUR PHYSIOLOGISCHE CHEMIE 1984;
365:419-26. [PMID:
6735353 DOI:
10.1515/bchm2.1984.365.1.419]
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Abstract
A sialidase was solubilized with the aid of Triton X-100 from the insoluble material of a leucocyte homogenate. The enzyme was purified almost to homogeneity by chromatography on Sephadex G-75, equine submandibular gland mucin bound to Sepharose 4B and on Sephacryl S-200. The purification factor was 40 based on an increase of the specific enzyme activity from the Triton X-100 extract (pure enzyme: 40 mU/mg protein). Isolation of the active enzyme required the presence of a proteinase inhibitor. The sialidase is monomeric and has an average molecular mass of 48500 Da, a pH optimum of 4.6, hydrolyses preferably glycoprotein (fetuin) and sialyllactose, is activated by Ca2 and inhibited by N-acetyl-2,3-dehydro-2- deoxyneuraminic acid ( Neu5Ac2en ), Hg2 and N-(4-nitrophenyl) oxamic acid. The relatively stable enzyme shows only low activity with gangliosides and no activity with 4-O-acetylated sialic acid bound glycosidically.
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