The temperature-dependence of both the lipid order parameter (S(DPH)) and acetylcholinesterase (AChE) activity from native and cholesterol-enriched human erythrocyte membranes was investigated. Cholesterol enrichment abolishes an inflection observed around 30°C in the temperature-dependence of native membrane lipid order parameter, whereas the Arrhenius plot of the enzymic activity is substantially unaffected. These results support the view that the breaks in the Arrhenius plot of the enzyme activity are not related to sudden changes of bulk membrane physical state, but arise from a direct effect of temperature on enzyme conformation.
Spinedi, A., Rufini, S., Luly, P., Farias, F. (1988). The temperature-dependence of human erythrocyte acetylcholinesterase activity is not affected by membrane cholesterol enrichment. BIOCHEMICAL JOURNAL, 255(2), 547-551.
The temperature-dependence of human erythrocyte acetylcholinesterase activity is not affected by membrane cholesterol enrichment
SPINEDI, ANGELO;RUFINI, STEFANO;LULY, PAOLO;
1988-01-01
Abstract
The temperature-dependence of both the lipid order parameter (S(DPH)) and acetylcholinesterase (AChE) activity from native and cholesterol-enriched human erythrocyte membranes was investigated. Cholesterol enrichment abolishes an inflection observed around 30°C in the temperature-dependence of native membrane lipid order parameter, whereas the Arrhenius plot of the enzymic activity is substantially unaffected. These results support the view that the breaks in the Arrhenius plot of the enzyme activity are not related to sudden changes of bulk membrane physical state, but arise from a direct effect of temperature on enzyme conformation.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
