O-sialoglycoprotein endopeptidase (OSGE)

O-sialoglycoprotein endopeptidase is a bacterial neutral metalloprotease, originally isolated from Pasteurella (Mannheimia) haemolytica, that specifically hydrolyzes O-sialoglycoproteins—proteins carrying clusters of negatively charged O-linked sialic acid residues. Its most characterized activity is the selective cleavage of the peptide bond between Arg^31 and Asp in human erythrocyte glycophorin A, but it also acts on other sialylated surface glycoproteins such as CD34, CD43, CD44, CD45, IL-7 receptor, selectin receptors, and certain tumor antigens. The enzyme does not cleave non-O-glycosylated proteins or those with only N-linked sugars, and its activity is inhibited by EDTA and certain sialate analogues, reflecting its metal ion (Zn^2+ dependent, though not directly activated) requirement. The enzyme is a valuable tool in glycobiology for removing or mapping O-sialoglycan-containing domains and for selective immunomagnetic separation of stem and immune cell populations[1][3][7][10].

Other names

glycoproteaseglycophorin A proteinaseglycoproteinasesialoglycoproteasesialoglycoproteinasePasteurella haemolytica glycoprotease

Cleaves peptide bonds specifically in O-sialoglycoproteins, most notably at the Arg^31-Asp bond in glycophorin A and other glycoproteins with O-linked sialic acids. Does not cleave non-O-glycosylated or N-linked glycoproteins