Sampedro José G, Uribe Salvador
Area Académica de Nutrición, Instituto de Ciencias de la Salud ICSA, Universidad Autónoma del Estado de Hidalgo, Pachuca, Hidalgo, Mexico.
Mol Cell Biochem. 2004 Jan-Feb;256-257(1-2):319-27. doi: 10.1023/b:mcbi.0000009878.21929.eb.
Stress resistance is essential for survival. The mechanisms of molecule stabilization during stress are of interest for biotechnology, where many enzymes and other biomolecules are increasingly used at high temperatures and/or salt concentrations. Diverse organisms, exhibit rapid synthesis and accumulation of the disaccharide trehalose in response to stress. Trehalose is also rapidly hydrolyzed as soon as stress ends. In isolated enzymes, trehalose stabilizes both, structure and activity. In contrast, at optimal assay conditions, trehalose inhibits enzyme activity. A general mechanism underlying the trehalose effects observed at all temperatures probably is the trehalose-mediated increase in solution viscosity that leads to protein domain motion inhibition. This may be analyzed using Kramer's theory. The role of viscosity in the effects of trehalose is analyzed in examples from the literature and in studies on the plasma membrane H(+)-ATPase from Kluyveromyces lactis. In the cell, it may be proposed that the large concentration of trehalose reached during stress stabilizes structures through viscosity. However, once stress ends trehalose has to be rapidly hydrolyzed in order to avoid the viscosity-mediated inhibition of enzymes.
抗逆性对生存至关重要。应激期间分子稳定的机制是生物技术所关注的，在生物技术领域，许多酶和其他生物分子越来越多地在高温和/或高盐浓度下使用。多种生物体在应激时会迅速合成并积累二糖海藻糖。一旦应激结束，海藻糖也会迅速水解。在分离的酶中，海藻糖既能稳定结构又能稳定活性。相比之下，在最佳测定条件下，海藻糖会抑制酶活性。在所有温度下观察到的海藻糖效应背后的一般机制可能是海藻糖介导的溶液粘度增加，从而导致蛋白质结构域运动受到抑制。这可以用克莱默理论进行分析。本文通过文献实例以及对乳酸克鲁维酵母质膜H(+)-ATP酶的研究，分析了粘度在海藻糖效应中的作用。在细胞中，可以推测应激期间达到的高浓度海藻糖通过粘度稳定结构。然而，一旦应激结束，海藻糖必须迅速水解，以避免粘度介导的酶抑制作用。
