来自Acacia koa的植物S-adenosylmethionine合成酶的表征
James T Carrillo1, Dulal Borthakur1
1University of Hawaii at Manoa, Department of Molecular Biosciences and Bioengineering, 1955 East-West Road, Agricultural Sciences 218, Honolulu, HI, 96822, USA.
Plant physiology and biochemistry : PPB
|April 17, 2024
概括
阿卡西亚可 S-adenosylmethionine合成酶表现出极高的稳定性,耐受高pH值,温度和盐度. 克服反抑制的策略,包括有机溶剂,增强酶活性.
科学领域:
- 生物化学 生化学
- 酶学 是一种酶学.
- 植物分子生物学 植物分子生物学
背景情况:
- S-adenosylmethionine (SAM) 合成酶在细胞代谢中起着至关重要的作用.
- 植物SAM合成酶的体外表征是有限的,阻碍了对其特性的理解.
研究的目的:
- 识别,克隆和表征来自 Acacia koa 的 S-adenosylmethionine (SAM) 合成酶.
- 研究在极端条件下酶的稳定性,并探索克服反抑制的方法.
主要方法:
- 将转录组数据分析和基因克隆转化为表达向量.
- 在不同的pH值,温度和盐度下进行酶活性测定.
- 位点定向突变发生和有机溶剂添加,以评估反抑制.
主要成果:
- 阿卡西亚 koa SAM合成酶表现出热性质,在pH10.5,55°C和3M KCl下稳定.
- 酶动力学与非植物SAM合成酶相似,没有观察到基质抑制.
- 突变性研究显示,变种中的活性降低和产品抑制增加.
- 有机溶剂 (乙二,甲醇,DMF) 显著提高了SAM的生产30-65%.
结论:
- 阿卡西亚 koa SAM合成酶具有显著的极端性特征,可能是植物酶的典型特征.
- 使用有机溶剂克服反抑制是改善体外酶活性的可行策略.
- 这项研究提供了植物SAM合成酶的第一个突变发生,为进一步研究开辟了道路.
相关概念视频
Allosteric Proteins-ATCase
5.7K
Binding sites linkages can regulate a protein's function. For example, enzyme activity is often regulated through a feedback mechanism where the end product of the biochemical process serves as an inhibitor.
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis...
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis...
5.7K
ATP Synthase: Mechanism
14.6K
In animals, the mitochondrial F1F0 ATP synthase is the key protein that synthesizes ATP molecules through a complex catalytic mechanism. While the nuclear genome encodes the majority of ATP synthase subunits, the mitochondrial genome encodes some of the enzyme's most critical components. The formation of this multi-subunit enzyme is a complex multi-step process regulated at the level of transcription, translation, and assembly. Defects in one or more of these steps can result in decreased...
14.6K
Cell Signaling in Plants
5.6K
Plant cells communicate to coordinate their cycle of growth, flowering and fruiting, and activities in roots, shoots, and leaves in response to the changing environmental conditions. Plant signaling is distinct from animal signaling. Plants primarily utilize enzyme-linked receptors, whereas the largest class of cell-surface receptors in animals are G-protein coupled receptors (GPCRs). Unlike animals, receptor tyrosine kinases are rare in plants. Instead, plants have a diverse class of...
5.6K
ATP Synthase: Structure
12.3K
ATP synthase or ATPase is among the most conserved proteins found in bacteria, mammals, and plants. This enzyme can catalyze a forward reaction in response to the electrochemical gradient, producing ATP from ADP and inorganic phosphate. ATP synthase can also work in a reverse direction by hydrolyzing ATP and generating an electrochemical gradient. Different forms of ATP synthases have evolved special features to meet the specific demands of the cell. Based on their specific feature, ATP...
12.3K


