TREHALOSE PROTECTS YEAST PYROPHOSPHATASE AGAINST STRUCTURAL AND FUNCTIONAL DAMAGE-INDUCED BY GUANIDINIUM CHLORIDE

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