Abstract
Ca2+-adenosine triphosphatase (ATPase) is an intrinsic membrane enzyme of muscle microsomes. The enzymic translocation of Ca2+ across the sarcoplasmic reticulum membrane is mediated by the formation of a phosphoenzyme intermediate in which the substrate is ATP. This procedure is believed to be accompanied by a conformational change in the protein molecule. Coupling between enzyme phosphorylation and the conformation of the Ca2+- ATPase has already received indirect support from certain biochemical experiments. In this paper, we report a new direct approach to investigate this coupling by monitoring laser-induced phosphorescence anisotropy from the triplet-label eosin bound covalently to the Ca2+- ATPase.
© 1992 IQEC
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