基于免疫融合结合因子改进的抗氨酸抗体
Yun Mou1,2, Xin X Zhou1, Kevin Leung1
1Department of Pharmaceutical Chemistry , University of California, San Francisco , San Francisco , California 94143 , United States.
Journal of the American Chemical Society
|November 7, 2018
概括
研究人员确定了泛特异性氨酸 (pY) 抗体的第一个晶体结构,揭示了保留的结合模式. 这一洞察力使得改进的pY抗体变体具有增强的结合亲和力,用于信号通路研究.
科学领域:
- 生物化学
- 结构生物学
- 免疫学
背景情况:
- 转化后的修改,如氨酸 (pY),是真核生物信号通路的关键调节者.
- 泛特异性pY抗体是研究这些修饰的有价值的工具,但它们的结构在很大程度上仍未被描述.
- 缺乏结构数据阻碍了基于pY抗体的新型工具的结构导向设计.
研究的目的:
- 确定广泛使用的泛特异性pY抗体 (PY20和4G10) 的第一个晶体结构.
- 阐明这些抗体对激素识别的结构基础.
- 使用结构导向设计和菌体显示来设计改进的pY抗体.
主要方法:
- 使用X射线结晶学来确定PY20和4G10抗体的结构.
- 进行了序列对齐,以确定生殖基因中常见的pY结合残留物.
- 用基于计算建模的 CDR-L3 循环构建了体显示库.
- 工程变体的结合亲属性被评估,并确定了它们的结构.
主要成果:
- PY20和4G10的晶体结构显示出具有惊人的相似的激素识别模式,这表明泛特异性pY抗体的通用结合结构.
- 序列分析表明这些抗体来自常见的小鼠V生殖基因的融合进化.
- 具有延长CDR- L3循环的4G10变体显示了4至11倍的pY结合亲和力.
- 一个改进的变体的结构分析证实了计算模型,并确定了额外的水媒.
结论:
- 确定结构为泛特异性激素抗体识别提供了第一个结构洞察力.
- 来自生殖系基因的融合进化有助于保持结合模式.
- 通过菌体显示的结构指导工程可以显著提高抗体结合亲和力和性能,如西方抹黑和免疫光.
相关概念视频
01:10Antibody Structure
65.6K
Overview
Antibodies, also known as immunoglobulins (Ig), are essential players of the adaptive immune system. These antigen-binding proteins are produced by B cells and make up 20 percent of the total blood plasma by weight. In mammals, antibodies fall into five different classes, which each elicits a different biological response upon antigen binding.
The Y-Shaped Structure of Antibodies Consists of Four Polypeptide Chains
Antibodies consist of four polypeptide chains: two identical heavy...
Antibodies, also known as immunoglobulins (Ig), are essential players of the adaptive immune system. These antigen-binding proteins are produced by B cells and make up 20 percent of the total blood plasma by weight. In mammals, antibodies fall into five different classes, which each elicits a different biological response upon antigen binding.
The Y-Shaped Structure of Antibodies Consists of Four Polypeptide Chains
Antibodies consist of four polypeptide chains: two identical heavy...
65.6K
02:18The Equilibrium Binding Constant and Binding Strength
15.1K
The equilibrium binding constant (Kb) quantifies the strength of a protein-ligand interaction. Kb can be calculated as follows when the reaction is at equilibrium:
15.1K
02:18The Equilibrium Binding Constant and Binding Strength
10.0K
10.0K
00:49What is Genetic Engineering?
80.2K
Overview
80.2K
02:07Improving Translational Accuracy
14.9K
Base complementarity between the three base pairs of mRNA codon and the tRNA anticodon is not a failsafe mechanism. Inaccuracies can range from a single mismatch to no correct base pairing at all. The free energy difference between the correct and nearly correct base pairs can be as small as 3 kcal/ mol. With complementarity being the only proofreading step, the estimated error frequency would be one wrong amino acid in every 100 amino acids incorporated. However, error frequencies observed in...
14.9K
02:13Nuclear Binding Energy
14.8K
The difference between the calculated and experimentally measured masses is known as the mass defect of the atom. In the case of helium-4, the mass defect indicates a “loss” in mass of 4.0331 amu – 4.0026 amu = 0.0305 amu. The loss in mass accompanying the formation of an atom from protons, neutrons, and electrons is due to the conversion of that mass into energy that is evolved as the atom forms. The nuclear binding energy is the energy produced when the atoms’ nucleons are bound...
14.8K