THE IMMUNOLOGICAL RELATEDNESS OF NEUROFILAMENT PROTEINS OF HIGHER VERTEBRATES

  • 1 January 1984
    • journal article
    • research article
    • Vol. 34  (1) , 130-136
Abstract
Intermediate filaments were prepared from the nervous system of several different species, representing mammals [rat, mouse, guinea pig, rabbit, cat, cow and pig], birds [goose and chicken] and reptiles [tortoise and lizard]. These were examined using a panel of polyclonal and monoclonal antibodies originally raised against pig or rat neurofilament proteins. All species studied possessed a single major protein of apparent MW between 68-75 K [kilodalton] immunologically related to the lowest MW rat and pig neurofilament protein. All birds and mammals possessed 2 proteins immunologically related to the pig and rat middle and high MW neurofilament proteins, respectively. The neurofilament triplet proteins represent an evolutionarily conserved 3 member protein family in birds and mammals, and allow for the suggestion of a new nomenclature for these 3 homologous proteins: H for the heaviest subunit M for the middle subunit and L for the lightest subunit. Many monoclonal antibodies stained both the H- and M-proteins of all mammalian and avian species examined, suggesting a close immunological relatedness between these 2 proteins. The reptiles examined appeared to have only 1 high MW protein, which was immunologically related to both of the high MW mammalian and avian neurofilament proteins. A curious situation in neurofilament preparations derived from cows was noted. Both the highest and the middle cow neurofilament proteins were stained by all antibodies which were specific solely for the high MW protein in other species.