title: Squid lens cytoskeleton and membrane proteins.
abstract: Cytoskeletal and membrane proteins were isolated from respectively the urea-soluble and urea-insoluble fractions of the squid lens. The main cytoskeletal polypeptide has a molecular weight (63000) and an amino acid composition similar to those of vertebrate intermediate filament proteins, including mammalian lens vimentins. Intermediate filaments, and bundles thereof, were regenerated from the squid lens urea-soluble fraction upon removal of urea. The main membrane polypeptide of 140000 Mr has an amino acid composition entirely different from that of the main intrinsic membrane protein of 26000 Mr which is found in all vertebrates. Although non-EDTA-extractable, the 140000 Mr squid membrane polypeptide is best classified as extrinsic, since it has a high polarity (mainly acidic residues) and can be degraded completely upon trypsin treatment of squid lens membranes.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002417:Cattle; D003459:Crystallins / Q000032:analysis*; D049832:Decapodiformes; D007908:Lens, Crystalline / Q000032:analysis* / Q000648:ultrastructure; D008565:Membrane Proteins / Q000032:analysis*; D008854:Microscopy, Electron; D010455:Peptides / Q000032:analysis
chemical_list: D000596:Amino Acids; D003459:Crystallins; D008565:Membrane Proteins; D010455:Peptides