Isolation and Characterization of an Oligosaccharide- and Glycoprotein-Specific Sialidase from Human Leucocytes

Publisher Website
Google Scholar
Abstract
A sialidase was solubilized with the aid of Triton X-100 from the insoluble material of a leukocyte 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 48,500 Da [dalton], a pH optimum of 4.6, hydrolyses preferably glycoprotein (fetuin) and sialyllactose, is activated by .**GRAPHIC**. and inhibited by N-acetyl-2,3-dehydro-2-deoxyneuraminic acid (Neu5Ac2en), .**GRAPHIC**. 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.

This publication has 24 references indexed in Scilit: