Fourier transform infrared spectroscopic studies on the secondary structure of the Ca2+-ATPase of sarcoplasmic reticulum.

Fourier transform infrared spectroscopy has been applied to the study of the secondary structure of the Ca2+-ATPase of sarcoplasmic reticulum. An attempt is made to quantitatively assess the various secondary structures present. Values of 45% alpha-helix, 32% beta-sheet and 23% turns were obtained. A comparison is made of these results and those obtained using other techniques such as CD and Raman spectroscopy. The various assumptions inherent in the present procedure are discussed. The effect of various ligands, e.g. Ca2+, vanadate, ATP and phosphate, upon the structure were investigated. Upon binding these ligands no marked spectral changes were observed.