Laminin is a glycoprotein (Mr 850 - 1.000 kD, consisting of 3 glycosylated polypeptide chains with molecular weights of 440 and 225 (2x) kD) produced by various human epithelial and mesenchymal cells, and forms an extracellular matrix of thin filaments. In normal tissues, laminin is invariably present in all basal laminas surrounding muscle, nerve, fat and decidua cells and separates epithelial and endothelial cells from abutting connective tissues. Laminin has also been identified within the cytoplasm of breast epithelia, stromal cells of the endometrium, and within endothelial, bile duct epithelial and mesenchymal cells of the liver. Laminin has been found to be involved in cellular activities such as adhesion, spreading, differentiation, polarization, proliferation, locomotion, tissue invasion and chemotactic responses. No cross reaction was obtained with human type I, III, IV and V collagen in immunoblotting, whereas the antibody reacted with a distinct band of appr. 200-220 kD from a 8M Urea extract from amnion basement membrane.
Positive control: skin, kidney.