Erythroagglutinin from Phaseolus coccineus var. Alubia: chemical characterization, sugar specificity, and effect on blood coagulation factors.

摘要

Purification of the erythroagglutinin from Phaseolus coccineus var. Alubia was achieved by affinity chromatography on human alpha1-acid glycoprotein and by ion exchange chromatography. The lectin is a tetrameric glycoprotein with MW 31 kDa/subunit and 8% sugar by weight, which agglutinates erythrocytes without serological specificity and is devoid of mitogenic activity toward human peripheral lymphocytes. The specificity of the erythroagglutinin is directed toward the Gal (beta1-4) or (beta1-3) GlcNAc (beta1-2) Man (alpha1-) saccharidic sequence present in bi- or triantennary N-acetyllactosamine-type N-glycopeptides or related glycans. Alubia erythroagglutinin inhibits the generation of human thrombin, probably by protecting prothrombin from enzymatic cleavage.