Neural cell adhesion molecules in rodent brains isolated by monoclonal antibodies with cross-species reactivity.

Abstract

Previous studies have led to the identification and purification of a chicken cell surface protein named neural cell adhesion molecule (N-CAM) that is involved in neural cell-cell and neurite-neurite interactions. In the present investigation, a similar molecule was found to exist in the mouse. It was also present in rat neural tissue. A monoclonal antibody to chicken N-CAM that crossreacted with mouse and rat brains and an independently derived monoclonal antibody to mouse N-CAM were used to purify an antigen from perinatal mouse and rat brains. The purified neural antigen resembles chicken N-CAM in its ability to neutralize antibodies that inhibit neural cell aggregation and also in its biochemical properties including MW, sialic acid content, amino acid composition and autoconversion to a smaller polypeptide. Like chicken N-CAM, the murine molecule is found throughout the nervous system and over the entire neuronal cell surface. Probably the molecule is evolutionarily related to chicken N-CAM and cell adhesion involving N-CAM is a fundamental mechanism existing in nervous systems of different phylogenetic classes of animals.