Brain ankyrin. Purification of a 72,000 Mr spectrin-binding domain.

摘要: Polypeptides of Mr = 190,000-220,000 that cross-react with erythrocyte ankyrin were detected in immunoblots membranes from pig lens, brain, and rat liver. The cross-reacting polypeptides brain cleaved by chymotrypsin to fragments 95,000 72,000 which are the same size as obtained ankyrin. fragment associated spectrin, binding occurred at site since (a) was adsorbed spectrin-agarose (b) 125I-labeled spectrin bound following transfer a sodium dodecyl sulfate gel nitrocellulose paper, this displaced fragment. Brain purified about 400-fold selective extraction continuous chromatography on columns attached series containing DEAE-cellulose followed coupled agarose, finally hydroxylapatite. not derived contaminating erythrocytes peptide maps distinct. amount estimated 0.28% membrane protein or 39 pmol/mg based radioimmunoassay antibody against tetramer present number copies (30 protein) densitometry Coomassie blue-stained gels. for both localized electron microscopy midregion tetramers 90 nM near end 110 far end. These studies demonstrate presence closely related ankyrin, consistent function attachment spectrin.