Primary structure of the target of calcium vector protein of amphioxus.

摘要: CaVPT, a target protein of Ca2(+)-vector from amphioxus muscle, was purified its complex with CaVP after dissociation by 6 M urea and chromatographies on DEAE-cellulose calmodulin-Sepharose. The amino acid sequence CaVPT has been determined. is composed 243 residues possesses an unblocked N terminus. Its molecular weight 26,621, distinctly lower than the apparent deduced electrophoresis sodium dodecyl sulfate-containing gels. contains potential Asn-linked glycosylation site, four kinase C phosphorylation sites, two casein II sites. From following three particular domains can be inferred: collagen-like N-terminal segment, rich in Pro Ala, that resembles segment skeletal muscle myosin light chain kinase; next to it (from 33 50) located strongly amphiphilic basic alpha-helical which likely binds calcium vector since proteolytic cut Arg50, occurring occasionally during purification impairs binding immobilized calmodulin. This followed immunoglobulin folds. folds typically belong C2 subclass particularly resemble those present neural cell surface adhesion molecules NCAM, L1, F11, MAG, TAG-1, fasciclin II, amalgam. Recently, presence this type reported some intracellular muscular proteins, namely smooth kinase, striated titin, as well nematode 600-kDa twitchin. structural study we formulate working hypothesis acts structure thick filament or regulates, perhaps via other fold-containing proteins.