The changes in conformation of (Na+ K+) -ATPase from rat brain membranes are accompanied by changes of protein segment movements in the nanosecond range
Amler, E.; Teisinger, J.; Svoboda, P.; Vyskocil, F.
Physiologia Bohemoslovaca 37(2): 145-148
1988
ISSN/ISBN: 0369-9463 PMID: 2850590 Document Number: 326386
Differential polarized phase fluorometry of fluorescein-5-isothiocyanate (FITC) showed that the activation of (Na,K)-ATPase in crude plasma membranes from rat brain by 10 mmol.l-1 K+ and 100 mmol.l-1 Na+ significantly increased the rotational relaxational rate (R) of enzyme-bound FITC. This increase was blocked by both ouabain (0.1 mmol.l-1) and vanadate (0.1 mmol.l-1). In the absence of ATP, R was increased less after adding of 10 mmol.l-1 K+ to the membranes. The shifts in the nanosecond movements of the protein segments measured as R during the activation of (Na,K)-ATPase suggest that this type of movement might be of some functional importance.