Hottiger T, De Virgilio C, Hall M N, Boller T, Wiemken A
Botanisches Institut, Universität Basel, Switzerland.
Eur J Biochem. 1994 Jan 15;219(1-2):187-93. doi: 10.1111/j.1432-1033.1994.tb19929.x.
In baker's yeast (Saccharomyces cerevisiae), accumulation of the non-reducing disaccharide, trehalose, is triggered by stimuli that activate the heat-shock response. Previously, trehalose levels have been shown to be closely correlated with thermotolerance, suggesting a protective function of this substance. Genetic evidence in support of this view is presented in an accompanying paper [De Virgilio, C., Hottiger, T., Dominguez, J., Boller, T. & Wiemken, A. (1993) Eur. J. Biochem. 219, 179-186]. In this study, we have examined the effect of trehalose on the thermal stability of proteins, a parameter thought to be a major determinant of thermotolerance. Physiological concentrations of trehalose (up to 0.5 M) were found to efficiently protect enzymes of yeast (glucose-6P-dehydrogenase, phosphoglucose-isomerase) as well as enzymes of non-yeast origin (bovine glutamic dehydrogenase, EcoRI) against heat inactivation in vitro. Trehalose also reduced the heat-induced formation of protein aggregates. The disaccharide proved to be a compatible solute, as even at very high concentrations (up to 1 M) it did not significantly interfere with the activity of test enzymes. Trehalose was at least as good or better a protein stabilizer than any of a number of other compatible solutes (including sugars, polyalcohols and amino acids), while the structurally related trehalose-6P was devoid of any protective effect. Thermoprotection of enzymes by trehalose was evident even in solutions containing high concentrations of yeast protein or substrate. The data indicate that trehalose accumulation may increase the thermotolerance of yeast by enhancing protein stability in intact cells.
在面包酵母（酿酒酵母）中，非还原性二糖海藻糖的积累是由激活热休克反应的刺激引发的。此前已表明，海藻糖水平与耐热性密切相关，这表明该物质具有保护功能。一篇随附论文[德·维尔吉利奥，C.，霍蒂格，T.，多明格斯，J.，博勒，T. & 维姆肯，A.（1993年）《欧洲生物化学杂志》219卷，179 - 186页]提供了支持这一观点的遗传学证据。在本研究中，我们研究了海藻糖对蛋白质热稳定性的影响，蛋白质热稳定性被认为是耐热性的一个主要决定因素。发现生理浓度的海藻糖（高达0.5 M）能有效保护酵母酶（葡萄糖 - 6 - 磷酸脱氢酶、磷酸葡萄糖异构酶）以及非酵母来源的酶（牛谷氨酸脱氢酶、EcoRI）在体外免受热失活影响。海藻糖还减少了热诱导的蛋白质聚集体形成。这种二糖被证明是一种相容性溶质，因为即使在非常高的浓度（高达1 M）下，它也不会显著干扰测试酶的活性。海藻糖作为蛋白质稳定剂至少与许多其他相容性溶质（包括糖类、多元醇和氨基酸）一样好或更好，而结构相关的海藻糖 - 6 - 磷酸则没有任何保护作用。即使在含有高浓度酵母蛋白或底物的溶液中，海藻糖对酶的热保护作用也很明显。数据表明，海藻糖的积累可能通过增强完整细胞中的蛋白质稳定性来提高酵母的耐热性。
