Molecular changes in the sarcoplasmic reticulum calcium ATPase during catalytic activity

FEBS Letters

Kreutz, Werner¹  Mäntele, Werner¹  Barth, Andreas¹ 

[1] Institut für Biophysik und Strahlenbiologie der Universität Freiburg, Albertstraße 23, D-7800 Freiburg, Germany

关键词: Ca2+-ATPase;    Sarcoplasmic reticulum;    Protein conformation;    Fourier transform infrared spectroscopy;    Caged ATP;    SR sarcoplasmic reticulum;    Ca2+-ATPase;    Ca2+-transporting ATPase (EC 3.6.1.38);    caged ATP;    P-1-(2-nitro)phenylethyl adenosine 5'-triphosphate;    (FT)IR;    (Fourier transform) infrared;    EGTA [ethyleneglycobis(oxyethylenenitrilo)] tetraacetic acid;   

DOI  :  10.1016/0014-5793(90)80830-C

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Fourier transform infrared spectroscopy was used to study ligand binding and conformational changes in the Ca²⁺-ATPase of sarcoplasmic reticulum. Novel in infrared difference spectroscopy, the catalytic cycle in the IR sample was started by photolytic release of ATP from an inactive, photolabile ATP-derivative (caged ATP). Small, but characteristic infrared absorbance changes were observed upon ATP release. On the basis of model spectra, the absorbance changes corresponding to the trigger and substrate reactions, i.e. to photolysis of caged ATP and hydrolysis of ATP, were separated from the absorbance changes due to the active ATPase reflecting formation of the phosphorylated Ca₂E₁P enzyme form. A major rearrangement of ATPase conformation as the result of catalysis can be excluded.

【 授权许可】

Unknown