Deduced amino acid sequence and E1–E2 equilibrium of the sarcoplasmic reticulum Ca2+‐ATPase of frog skeletal muscle Comparison with the Ca2+‐ATPase of rabbit fast twitch muscle

FEBS Letters

Andersen, Jens Peter¹  Vilsen, Bente¹ 

[1] Danish Biomembrane Research Centre, Institute of Physiology, University of Aarhus, DK-8000 Aarhus C, Denmark

关键词: Ca2+-ATPase;    Sarcoplasmic reticulum;    Amino acid sequence comparison;    Frog muscle;    Ca2+ affinity;    bp;    base pair(s);    Ca2+-ATPase;    Ca2+-activated adenosine triphosphatase;    EGTA;    [ethylenebis(oxyethylene-nitrilo)]-tetraacetic acid;    ER;    endoplasmic reticulum;    kb;    kilo bases;    MOPS;    3-(N-morpholino)propanesulfonic acid;    oligo(dT);    oligodeoxythymidine;    poly(A+);    polyadenosine;    TES;    N-tris[-hydroxymethyl]methyl-2-aminoethanesulfonic acid;    SDS;    sodium dodecyl sulfate;    SERCA;    sarco(endo)plasmic reticulum Ca2+-ATPase;    SR;    sarcoplasmic reticulum;   

DOI  :  10.1016/0014-5793(92)81003-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The cDNA encoding a Ca²⁺-transport ATPase of frog (Rana esculenia) skeletal muscle was isolated and characterized. The deduced amino acid sequence, consisting of 994 residues, showed 89% identity to the fast twitch muscle sarcoplasmic reticulum Ca²⁺-ATPases of chicken and rabbit. Northern blot analysis using a fragment of this cDNA as probe detected a 5.0 kb message in frog skeletal muscle but did not detect any mRNA encoding sarcoplasmic reticulum Ca²⁺-ATPase in frog cardiac muscle. The enzymatic properties of the amphibian skeletal muscle Ca²⁺-ATPase were compared with those of the rabbit fast twitch muscle Ca²⁺-ATPase by functional expression of the cDNAs in COS-1 cells. The amphibian Ca²⁺-ATPase displayed a reduced apparent affinity for Ca²⁺ and an increased apparent affinity for the inhibitors, vanadate and thapsigargin, relative to the mammalian enzyme. This may be explained by a mechanism in which relatively more of the E₂ conformation accumulated ¹n the frog Ca²⁺-ATPase than in the mammalian enzyme.

【 授权许可】

Unknown