Isolation and characterization of galectin-1 binding proteins from human placenta

• Main Author: MIROSLAVA JANKOVIC
• Format: Article
• Language: English
• Published: Serbian Chemical Society 2000-02-01
• Series: Journal of the Serbian Chemical Society
• Subjects: galectin-1; human placenta; affinity chromatography; RCA I; CA19-9
• Online Access: http://www.shd.org.yu/HtDocs/SHD/Vol65/No2-Pdf/V65-No2-07.zip

Galectin-1 binding proteins were isolated from human placenta by affinity chromatography on a column with immobilized endogenous lectin. The molecular masses of the isolated proteins of 170, 67 and 56 kDa were estimated by gel filtration and SDS-PAGE. These proteins were characterized as galactose-containing glycoproteins, based on their reactivity with Ricinus communis agglutinin. In addition, sialylated-lacto-N-fucopentaose II was detected in the 170 kDa protein, using anti CA 19-9 monoclonal antibodies. The interaction of the isolated proteins with human placental galectin-1 was investigated by a solid phase binding assay using asialofetuin as the glycoprotein ligand. The 67 kDa and 56 kDa proteins were found to inhibit galectin-1 binding of asialofetuin, whereas the 170 kDa protein had the opposite effect. It caused an increase in the binding of asialofetuin, suggesting a positive cooperative binding.