Trehalose protects yeast pyrophosphatase against structural and functional damage induced by guanidinium chloride.

Trehalose is accumulated at very high concentrations in yeasts when this organism is submitted to a stress condition. This report approaches the question on the protective effect of trehalose and its degradation product, glucose, against structural and functional damage promoted by guanidinium on yeast cytosolic pyrophosphatase. Here it is shown that both, 1 M trehalose or 2 M glucose, are able to attenuate at almost the same extent the conformational changes promoted by guanidinium chloride on the pyrophosphatase structure. On the other hand while 1 M trehalose increases 3.8 times the Ki (from 0.15 to 0.57 M) for guanidinium chloride inhibition of pyrophosphatase activity, 2 M glucose did not even duplicate this parameter (from 0.15 to 0.25 M). These data support evidences for a functional reason for the accumulation by yeasts of trehalose, and not other compound, during stress conditions.