BIOCHEMICAL AND IMMUNOCHEMICAL IDENTIFICATION OF A MICROTUBULE-BINDING PROTEIN FROM BOVINE PANCREAS

We have identified a 67 kDa heat-stable protein among the proteins whi ch bind specifically to brain microtubules immobilized on a chromatogr aphic support. Its relationship to tubulin and to the cytoskeleton usi ng polyclonal antibodies has been studied. This 67 kDa protein is pres ent in cytoskeleton and microtubule preparations from pancreas. This h eat-stable microtubule-associated protein (MAP) copolymerized with pho sphocellulose purified brain tubulin. The 67 kDa polypeptide was immun oreactive to antibodies against the 210 kDa MAP from HeLa cells; it al so reacted with antibodies against an oligopeptide whose sequence corr esponded to the second repeat of mouse brain tau. (C) 1993 Wiley-Liss, Inc.