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对两个具有高序列同一性的α-L-rhamnosidases进行比较研究

Jiayuan Dai¹, Yichun Zhang¹, Ting Gao¹

¹College of Ocean Food and Biological Engineering, Jimei University, Xiamen 361021, China.

International journal of biological macromolecules

|July 31, 2024

概括

这项研究比较了两个Aspergillusα-L-rhamnosidases,AK-Rha和AT-Rha. 虽然这两种酶都向纳林丁,但由于结构灵活性和有利的溶解,AT-Rha表现出明显更高的活性,为酶基质相互作用提供了洞察力.

科学领域:

酶学是一种酶学.
生物化学生物化学
结构生物学结构生物学

背景情况:

来自Aspergillus tubingensis (AT-Rha) 的GH78α-L-rhamnosidase代表了Aspergillus酶中的一个独特的组.
为了进行比较分析,研究了一种非常相似的酶,来自A. kawachii IFO 4308的AK-Rha.

研究的目的:

为了表达和描述来自Aspergillus kawachii的重组AK-Rha (AK-rRha).
为了比较AK-rha与AT-Rha的酶性质和结构特征.
阐明两个酶之间的催化效率差异的结构基础.

主要方法:

在Pichia pastoris中进行重组蛋白表达.
用纳林金作为基质进行酶活性测定.
模拟分子动力学以分析酶的结构和灵活性.
极地溶解能量分析,以评估甘氨酸键的水解.

主要成果:

与AT-Rha (125.142 U/mg) 相比,AK-rha表现出显著较低的酶活性 (0.816 U/mg),以对抗naringin.
催化效率的差异主要归因于AK-rRha (0.67 s-1) 与AT-Rha (4.89 × 104 s-1) 的kcat值较低.
分子动力学模拟显示,AK-Rha在构造上是刚性的,而AT-Rha是灵活的,Loop Y-L影响了naringin相互作用和固体阻碍.

结论:

无论是AK-Rha还是AT-Rha,都表现出狭窄的基质特异性对宁,这是Aspergillus alpha-L-rhamnosidases的特征.
结构灵活性和溶解能量显著影响这些酶的催化效率.
这项研究提供了有关酶的不同催化能力的结构性见解.

关键词:

酶活性的酶活动.结构与活动的关系.α-L-Rhamnosidase的使用情况

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