Immunochemical characterization of antisera to rat neurofilament subunits.

Antisera raised to the 68,000, 145,000 and 200,000 molecular weight subunits of rat neurofilaments were used for immunochemical staining of polypeptides separated by one- and two-dimensional gel electrophoresis. It was found that each antiserum reacts intensely with its corresponding neurofilament subunit and weakly with the other two subunits. All the antisera also react with a polypeptide of molecular weight 57,000 present in neurofilament-rich preparations from both rat spinal cord and peripheral nerve. This polypeptide is different from either tubulin or vimentin and may represent a neurofilament breakdown product, since it varied in amount from preparation to preparation. The three antisera also reacted with the polypeptide subunits of chicken and goldfish neurofilament despite the considerable difference in molecular weight between these subunits and those of mammalian neurofilament.