Adult human brain expresses four different molecular forms of neural cell adhesion molecules.

Using antibodies to rat neural cell adhesion molecules (NCAM), we analyzed the NCAM of adult human brain. Various regions of the brain were analyzed quantitatively by Western blot. Grey matter showed four bands of NCAM with apparent molecular weights of 180,000, 170,000, 140,000 and 120,000. White matter showed one major band with an apparent M(r) of 120,000 and a minor band of 180,000. Cerebellar grey matter contained mainly 170,000, 140,000 and 120,000, white cerebellar white matter had only 180,000 and 120,000 M(1) NCAMS. Spinal cord showed mainly 120,000 M(r) NCAM. Deglycosylation using N-glycanase resulted in 170,000, 160,000, 130,000 and 110,000 M(r) proteins, suggesting that the four forms of human NCAM are derived from individual polypeptides. The presence of 170,000 M(1) NCAM is unique to human brain.