Abstract
Ca2+-ATPase from skeletal muscle sarcoplasmic reticulum was reconstituted into liposomes with (100-1000 fold) or without transmembrane Ca2+ gradient. The highest enzyme activity and Ca2+ uptake were observed in the vesicles without transmembrane Ca2+ gradient. If there existed transmembrane Ca2+ gradient, no matter what the direction was, a lower activity would appear. Dissipation of transmembrane Ca2+ gradient by A23187 could lead to a change in enzyme activity of incorporated Ca2+-ATPase. A concomitant change of lipid fluidity of proteoliposomes with that of enzyme activity and Ca2+ uptake was observed. The inhibition of Ca2+-ATPase by the transmembrane Ca2+ gradient could be observed in the PC-PE vesicles, but not in the PS-PE or PG-PE proteoliposomes.
Original language | English (US) |
---|---|
Pages (from-to) | 561-568 |
Number of pages | 8 |
Journal | Biochemical and Biophysical Research Communications |
Volume | 196 |
Issue number | 2 |
DOIs | |
State | Published - Oct 29 1993 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- Biophysics
- Biochemistry
- Molecular Biology
- Cell Biology