Molecular crowding elicits the acceleration of enzymatic crosslinking of macromolecular substrates
Molecular crowding elicits the acceleration of enzymatic crosslinking of macromolecular substrates
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DOI：
10.1039/d2ob01549h
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发表时间：
2022-11-01
影响因子：
3.2
通讯作者：
Kamiya, Noriho
中科院分区：
文献类型：
--
作者：
Sato, Ryo;Minamihata, Kosuke;Kamiya, Noriho
细胞质中含有高浓度的生物大分子。据报道，蛋白质在这种拥挤条件下的行为与在水缓冲溶液中的行为不同，这主要是由于大分子存在引起的体积排斥效应。本文以微生物谷氨酰胺转胺酶（MTG）催化的交联反应为模型，系统地确定了底物大小在稀释和拥挤的葡聚糖溶液中如何影响酶活性。我们首先观察到在15%葡聚糖溶液中，mtg介导的一对小肽底物的交联减少了三倍。相反，当涉及蛋白质底物时，15%葡聚糖溶液中的交联速率明显加快，与不含葡聚糖的水平相当。我们的研究结果为酶在拥挤条件下对大分子底物的作用提供了新的见解，其中潜在的效用是通过形成高度交联的蛋白质聚合物来证明的。
Cytoplasm contains high concentrations of biomacromolecules. Protein behavior under such crowded conditions is reportedly different from that in an aqueous buffer solution, mainly owing to the effect of volume exclusion caused by the presence of macromolecules. Using a crosslinking reaction catalyzed by microbial transglutaminase (MTG) as a model, we herein systematically determined how the substrate size affects enzymatic activity in both dilute and crowded solutions of dextran. We first observed a threefold reduction in MTG-mediated crosslinking of a pair of small peptide substrates in 15 wt% dextran solution. In contrast, when proteinaceous substrates were involved, the crosslinking rates in 15 wt% dextran solutions accelerated markedly to levels comparable with the level in the absence of dextran. Our results provide new insights into the action of enzymes with regard to macromolecular substrates under crowded conditions, of which the potential utility was demonstrated by the formation of highly crosslinked protein polymers.