Role of malectin in Glc(2)Man(9)GlcNAc(2)-dependent quality control of α1-antitrypsin.

ABSTRACT: Malectin was first discovered as a novel endoplasmic reticulum (ER)-resident lectin from Xenopus laevis that exhibits structural similarity to bacterial glycosylhydrolases. Like other intracellular lectins involved in glycoprotein quality control, malectin is highly conserved in animals. Here results from in vitro membrane-based binding assays and frontal affinity chromatography confirm that human malectin binds specifically to Glc(2)Man(9)GlcNAc(2) (G2M9) N-glycan, with a K(a) of 1.97 × 10(5) M(-1), whereas binding to Glc(1)Man(9)GlcNAc(2) (G1M9), Glc(3)Man(9)GlcNAc(2) (G3M9), and other N-glycans is barely detectable. Metabolic labeling and immunoprecipitation experiments demonstrate that before entering the calnexin cycle, the folding-defective human α1-antitrypsin variant null Hong Kong

SUBMITTER: Chen Y 

PROVIDER: S-EPMC3183012 | biostudies-literature | 2011 Oct

REPOSITORIES: biostudies-literature