Integral Membrane Glycoproteins Related to Cell–Substratum Adhesion in Mammalian Cells

Abstract

Broad spectrum antisera have been raised against surface membrane‐derived material from baby hamster kidney cells and mouse mammary tumor epithelial cells. These antisera disrupt cell–substratum adhesion in their respective cell types. Using an antibody neutralization (blocking) assay, adhesion‐related glycoproteins have been isolated from non‐ionic detergent extracts of each cell type. The purified material in each case consisted of a restricted population of glycoproteins of approximately 120,000–160,000 M_r. Purified material from each system blocked the disruption of adhesion induced by the heterologous antiserum on either cell type. The antisera were capable of disrupting cell–substratum adhesion of a large number of cell types and species sources. In addition, antibody blocking activity could be detected from partially purified extracts of several adult hamster cell types and a variety‐of cultured cell types. Thus, in addition to having similar substratum–associated glycoproteins (eg, fibronectin) and cytoskeleton‐associated proteins (eg, α‐actinin and vinculin) cells from different species and tissue sources appear to have a relatively conserved class of integral membrane glycoproteins involved in cell substratum–adhesion.