Kinetics of the thermal inactivation and aggregate formation of rabbit muscle pyruvate kinase in the presence of trehalose
Kinetics of the thermal inactivation and aggregate formation of rabbit muscle pyruvate kinase in the presence of trehalose
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DOI：
10.1016/j.abb.2009.08.012
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发表时间：
2009-10-15
影响因子：
3.9
通讯作者：
Ramirez-Silva, Leticia
中科院分区：
文献类型：
--
作者：
Guerrero-Mendiola, Carlos;Oria-Hernandez, Jesus;Ramirez-Silva, Leticia
在先前的研究中，我们发现30-40%的二甲基亚砜可以诱导兔肌肉丙酮酸激酶的活性构象。由于二甲基亚砜干扰了许多蛋白质的结构和功能，我们探索了海藻糖对丙酮酸激酶的热失活动力学和稳定性的影响，这是因为与二甲基亚砜相比，海藻糖完全被排除在蛋白质的水合壳层之外。结果表明，在25℃时，600 mM海藻糖对丙酮酸激酶活性的抑制约为20%，而在60℃时，海藻糖可保护丙酮酸激酶不受热失活的影响，使其去折叠的TM-APP增加7.2℃，使其更加致密，并稳定其四聚体结构。由于蛋白质聚集体的形成，失活过程是不可逆转的。海藻糖降低了有聚集倾向的中间体的形成速度，但不影响聚集的程度。值得注意的是，海藻糖通过诱导具有淀粉样特性的聚集体来影响聚集过程。(C)2009 Elsevier Inc.保留所有权利。
In a previous study we found that 30-40% dimethylsulfoxide induces the active conformation of rabbit muscle pyruvate kinase. Because dimethylsulfoxide is known to perturb structure and function of many proteins, we have explored the effect of trehalose on the kinetics of thermal inactivation and stability of pyruvate kinase; this is because trehalose, in contrast to dimethyl sulfoxide, is totally excluded from the hydration shell of proteins. The results show that 600 mM trehalose inhibits the activity of pyruvate kinase by about 20% at 25 degrees C, however, trehalose protects pyruvate kinase from thermal inactivation at 60 degrees C, increases the Tm-app of unfolding by 7.2 degrees C, induces a more compact state, and stabilizes its tetrameric structure. The inactivation process is irreversible due to the formation of protein aggregates. Trehalose diminishes the rate of formation of intermediates with propensity to aggregate, but does not affect the extent of aggregation. Remarkably, trehalose affects the aggregation process by inducing aggregates with amyloid-like characteristics. (C) 2009 Elsevier Inc. All rights reserved.