相关实验视频
Updated: Jun 5, 2025

09:16
Oligopeptide Competition Assay for Phosphorylation Site Determination
Published on: May 18, 2017
8.4K
氧化CaMKIIα半氨酸抑制了由酸化诱导的自主激活
Nathália Rocco-Machado1, Max Deng1, Yi He2
1Laboratory of Biochemistry, National Heart, Lung and Blood Institute, Maryland, USA.
Archives of biochemistry and biophysics
|December 14, 2024
概括
阿尔茨海默病通过囊氧化损害了CaMKIIα的功能,形成了阻断Thr286酸化的二硫化键. 这种二硫化物形成减少了CaMKIIα的自主激活,导致突触功能障碍.
科学领域:
- 神经科学是一个神经科学.
- 分子生物学分子生物学
- 生物化学 生物化学
背景情况:
- 通过Thr286酸化对Ca2+/calmodulin依赖蛋白激酶IIα (CaMKIIα) 的自主激活对于突触可塑性至关重要.
- 阿尔茨海默氏症 (AD) 大脑在Thr286表现出降低的CaMKIIα自酸化和增加的囊氧化.
研究的目的:
- 为了阐明在阿尔茨海默病中CaMKIIα囊氧化的机制.
- 研究二硫化物形成对CaMKIIα活性的影响及其在AD相关突触障碍中的作用.
主要方法:
- 氧化CaMKIIα的三图绘制,以确定二硫化物键的形成.
- 对Cys6和Cys280.0的明显pKa值的测量.
- 使用对酸化Thr286的抗体来评估酸化状态.
- 产生一个Cys6-to-Ser6突变的CaMKIIα来评估Cys6.6的作用.
主要成果:
- 在氧化CaMKIIα中,N端Cys6和调节域Cys280之间形成二硫化键.
- Cys6 (7.1) 和Cys280 (7.7) 的表面pKa值在生理pH下促进了二硫化物键的形成.
- 硫化物形成抑制了CaMKIIα在Thr286.6的酸化.
- 通过二硫化物介导的CaMKIIα的自主激活明显低于通过酸化介导的激活.
- 突变Cys6到Ser6阻止了二硫化物形成,并恢复了CaMKIIα的自主激活.
结论:
- 在CaMKIIα中,Cys6和Cys280之间的二硫化键形成是导致阿尔茨海默病自主激活减少的关键机制.
- 这种受损的CaMKIIα活性可能是突触缺陷的基础,包括在AD中观察到的长期强化损伤.
- 准或理解这种二硫化物键形成可能为阿尔茨海默病提供治疗途径.
相关概念视频
Calmodulin-dependent Signaling
5.1K
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,...
5.1K
Amplifying Signals via Enzymatic Cascade
8.3K
When a ligand binds to a cell-surface receptor, the receptor's intracellular domain changes shape, which may either activate its enzyme function or allow its binding to other molecules. The initial signal is amplified by most signal transduction pathways. This means that a single ligand molecule can activate multiple molecules of a downstream target. Proteins that relay a signal are most commonly phosphorylated at one or more sites, activating or inactivating the protein. Kinases catalyze...
8.3K
cAMP-dependent Protein Kinase Pathways
6.1K
Cyclic Adenosine Monophosphate (cAMP) is an essential second messenger that activates protein kinase A (PKA) and regulates various biological processes. A single epinephrine molecule binds to GPCR and activates several heterotrimeric G proteins, each stimulating multiple adenylyl cyclase, amplifying the signal, and synthesizing large numbers of cAMP molecules. Small changes in cAMP concentration affect PKA activity. The binding of four cAMP molecules induces a conformational change in PKA,...
6.1K
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
Protein Kinases and Phosphatases
13.0K
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...
13.0K
Anaphase Promoting Complex
2.8K
The stepwise destruction of specific proteins is necessary for the progression and completion of the cell cycle. Such proteins are ubiquitinated by ubiquitin ligases and then subsequently destroyed by the proteasome. The SCF (Skp1/Cullin/F-box) and the anaphase-promoting complex (APC) are two important ubiquitin ligases involved in cell cycle progression. While SCF is active throughout the cell cycle, APC gets activated during metaphase to anaphase transition. Cdc20 or Cdh1 binds to APC and...
2.8K

