endo-beta-N-acetylglucosaminidase F: endoglycosidase from Flavobacterium meningosepticum that cleaves both high-mannose and complex glycoproteins.

TLDR

Endo F is intended to aid in dissecting glycans from protein backbones and elucidating the glycan‑protein interface. We identified endo F, an endoglycosidase from *Flavobacterium meningosepticum*, that cleaves both high‑mannose and complex N‑glycans via hydrolysis of the core N,N′‑diacetylchitobiose, exhibiting broad substrate specificity but requiring reducing conditions for some proteins.

Abstract

We have detected an endoglycosidase activity produced by Flavobacterium meningosepticum. This enzyme, named endo F, cleaves glycans of both the high-mannose and the complex type linked through asparagine to the protein backbone. The data indicate that cleavage occurs via hydrolysis of the glycosidic bond of the N,N'-diacetylchitobiose core structure adjacent to asparagine, similar to that due to endo H and endo D. Extreme variability was noted in the availability of this cleavage site among N-linked glycoproteins. Glycoproteins of retrovirus, lymphocytic choriomeningitis virus, Pichinde virus, and HLA-A and -B antigens were readily cleaved in the presence of nonionic detergent. Others, such as ovalbumin, fetuin, bromelain, ovomucoid, alpha 1-acid glycoprotein, immunoglobulin G, and influenza virus hemagglutinin became susceptible only after reduction and alkylation or when cleavage was performed in the presence of 1% 2-mercaptoethanol. Endo F should prove useful in the study of glycans and protein backbones as discrete entities and for defining the nature of the glycan-protein interface.