ENPP1 ATPase的动力机制:对异常化障碍和酶替代疗法的影响
Marisa M Michalchik1, Tony Potchernikov1, Ethan R Lester2
1Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, 06520, USA.
The Journal of biological chemistry
|August 6, 2025
概括
乙核酸铁酸盐化酶1 (ENPP1) 酶活性被动力学分析. 了解 ENPP1 的理解
科学领域:
- 生物化学和酶学 生物化学和酶学
- 分子生物学分子生物学
- 生理学 生理学 生理学
背景情况:
- 乙核酸铁酸盐化酶1 (ENPP1) 对于调节细胞外铁酸盐 (PPi) 水平至关重要,这对于预防动脉化至关重要.
- 缺少ENPP1导致严重的动脉化,并危及生命,但其PPi释放的精确分子机制尚不清楚.
- 酶替代疗法 (ERT) 在临床试验中显示出对ENPP1缺乏的承诺,强调需要更深入地了解ENPP1的催化功能.
研究的目的:
- 通过动力学分析阐明由核核酸酸酶二酶1 (ENPP1) 释放的酸 (PPi) 的分子机制.
- 为了确定ENPP1 ATPase催化循环的速度限制步骤和动力参数.
- 了解ENPP1活动是如何通过基质 (ATP) 和产品 (AMP) 度与生理水平相关调节的.
主要方法:
- 详细的动力学分析的乙核酸铁酸酶化酶1 (ENPP1) 催化ATPase循环.
- 测量反应速率,基质亲和力 (KM,T) 和产品抑制常数.
- 动力学参数与ATP和AMP的生理度的比较.
主要成果:
- 动力学分析显示了快速的ATP裂变,PPi释放和AMP-ENPP1中间水解 (>1000秒-1),AMP产品释放是缓慢的,速度限制的步骤.
- 对于ATP,迈克利斯常数 (KM,T) 与生理血清ATP水平 (~100nM) 相当,表明对ATP波动的敏感性.
- 在生理学AMP度 (~100nM) 中,ENPP1表现出AMP的产品抑制,具有强烈的AMP结合 (相似于KM,T的亲和力),表明内在反调节.
结论:
- 缓慢的AMP产品释放是ENPP1 ATPase循环中的速度限制步骤.
- ENPP1活动对生理ATP水平敏感,并且受到AMP的负反调节,这有助于保持稳定的血PPi水平.
- 这些定量参数为预测ENPP1 ERT的疗效和了解其他与PPi相关的化障碍提供了基础.
相关概念视频
ATP Synthase: Mechanism
15.2K
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...
15.2K
Protein Kinases and Phosphatases
13.4K
Proteins undergo chemical modifications that trigger changes in the charge, structure, and conformation of the proteins. Phosphorylation, acetylation, glycosylation, nitrosylation, ubiquitination, lipidation, methylation, and proteolysis are various protein modifications that regulate protein activity. Such modifications are usually enzyme-driven.
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
13.4K
ATP Driven Pumps II: P-type Pumps
5.1K
The P-type pumps are a large family of integral membrane transporter ATPases. They are divided into five major types based on substrate specificity, from I to V.
A typical P-type pump has three cytosolic domains: nucleotide-binding (N), phosphorylation (P), and activator (A) domains. These domains are connected to the membrane-spanning helices by short amino acid segments. ATP hydrolysis and covalent phosphoenzyme intermediate formation are crucial parts of the catalytic cycle. At the highly...
A typical P-type pump has three cytosolic domains: nucleotide-binding (N), phosphorylation (P), and activator (A) domains. These domains are connected to the membrane-spanning helices by short amino acid segments. ATP hydrolysis and covalent phosphoenzyme intermediate formation are crucial parts of the catalytic cycle. At the highly...
5.1K
Calmodulin-dependent Signaling
5.3K
Calmodulin (CaM) is a calcium-binding protein in eukaryotes that controls various calcium-regulated cellular processes. It has four calcium-binding sites that bind calcium to form the calcium-calmodulin ( Ca2+-CaM) complex. GPCR stimulation increases the calcium levels in the cells that bind to CaM and induces a conformational change.
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
5.3K
ATP Synthase: Structure
13.1K
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...
13.1K
Transducer Mechanism: Enzyme-Linked Receptors
2.8K
Enzyme-linked receptors are cell-surface receptors acting as an enzyme or associating with an enzyme intracellularly. They make excellent drug targets. Drugs can bind to the extracellular ligand-binding domain or directly affect their enzymatic domain and alter their activity.
Major types that are helpful drug targets include:
Major types that are helpful drug targets include:
2.8K


