Investigation of conformational changes in yeast enolase using dynamic fluorescence and steady-state quenching measurements.

Conformational changes in yeast enolase were investigated using steady state quenching and dynamic (fluorescence decay and fluorescence anisotropy decay) measurements. The tryptophan fluorescence rotational correlation time increases from 24 to 38 ns on subunit association. The acrylamide quenching constant decreases two-fold when the subunits associate. The conformational metal ion effect suggests a more compact molecule. Under conditions of catalysis, the correlation time decreases 25%, though the sedimentation constant does not change (Holleman, 1973). The enzyme may undergo a hinge-bending motion during catalysis.