Temperature-dependent conformational changes in isolated oligomycin-sensitive ATPase

Isolated oligomycin-sensitive ATPase undergoes a kinetic change at 20-25 degrees C with a higher activation energy and a lower Km for ATP below this temperature range. This observation has been correlated with temperature-dependent structural changes detected by circular dichroism in the UV region in the isolated enzyme. The negative ellipticities in the 208-225 nm region, which are proportional to the alpha-helix content, increase with rise in temperature to a maximum above 25 degrees C.