概括
兰巴达2光链中的单个氨基酸从甘氨酸转变为氨酸,可以防止其分泌. 在免疫球蛋白A (IgA) 髓瘤细胞的可变区域中,这种糖氨酸替代氨酸会影响蛋白质出口.
科学领域:
- 分子生物学分子生物学
- 免疫学 免疫学 免疫学
- 蛋白质生物化学 蛋白质生物化学
背景情况:
- 研究了两种IgA (lambda2) 分泌髓瘤细胞系MOPC315.15的衍生物.
- MOPC315.26分泌兰巴达2光链,而MOPC315.37产生但不分泌它.
- 以前的研究表明,MOPC315-37的lambda2链的变化是在变量区域.
研究的目的:
- 为了确定负责MOPC315.37.3中的lambda 2光链非分泌的特定分子变化.
- 阐明单个氨基酸替代对蛋白质分泌的影响.
主要方法:
- 从分泌 (MOPC315.26) 和非分泌 (MOPC315.37) 髓瘤细胞系克隆了重新排列的兰巴达2基因片段.
- 确定克隆的兰巴达2基因的核酸序列.
主要成果:
- 兰巴达2链的领导和常数区域的核酸序列在两个细胞系中都相同.
- 变量区域的序列在氨基酸位置15的单个基对不同.
- 在这个位置,MOPC315.26含有甘氨酸 (GGT),而MOPC315.37含有氨酸 (CGT).
结论:
- 一个单一的氨基酸替代,甘氨酸 (中性) 到氨酸 (正电荷),在Lambda 2光链的变量区域导致蛋白质分泌的失败.
- 这一发现强调了特定氨基酸特性在蛋白质运输和分泌途径中的关键作用.
相关概念视频
Antibody Structure
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...
Protein Complexes with Interchangeable Parts
Groups of proteins may form a complex where each protein in this complex has a different role in the overall execution of the complex’s function. Often some of the proteins in the complex can be replaced by a closely related variant to give a complex that contains many of the same components yet is functionally distinct.
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order to...
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order to...
Leaky Scanning
During most eukaryotic translation processes, the small 40S ribosome subunit scans an mRNA from its 5' end until it encounters the first start AUG codon. The large 60S ribosomal subunit then joins the smaller one to initiate protein synthesis. The location of the translation initiation is largely determined by the nucleotides near the start codon as there may be multiple translation initiation sites present on the mRNA. Marilyn Kozak discovered that the sequence RCCAUGG (where R stands for...
Insertion of Single-pass Transmembrane Proteins in the RER
Integral membrane proteins are proteins adhered to the lipid bilayer of a cell organelle or membrane. They can be of two types: transmembrane integral proteins that span the lipid bilayer and monotopic proteins that are attached to either side of the membrane but do not pass through it.
Integral transmembrane proteins possess transmembrane and extra membrane domains. The transmembrane domains are primarily made of 20-25 hydrophobic amino acids arranged in a helical secondary confirmation. These...
Integral transmembrane proteins possess transmembrane and extra membrane domains. The transmembrane domains are primarily made of 20-25 hydrophobic amino acids arranged in a helical secondary confirmation. These...
Diversity of Antigen Receptors
Antigen receptors are essential components of the immune system crucial in defending the body against foreign invaders. These receptors are present on the surface of B and T cells, enabling them to recognize antigens and mount an appropriate immune response.
Before encountering any antigen, lymphocytes express these receptors. On B cells, the antigen receptor is a membrane-bound antibody molecule called BCR; on T cells, it is a T cell receptor or TCR. B and T cell receptors are composed of two...
Before encountering any antigen, lymphocytes express these receptors. On B cells, the antigen receptor is a membrane-bound antibody molecule called BCR; on T cells, it is a T cell receptor or TCR. B and T cell receptors are composed of two...
Antibody Structure and Classes
Antibodies, also known as immunoglobulins, are produced by B cells in response to foreign substances, such as bacteria and viruses. These proteins are critical for recognizing and neutralizing these substances, protecting the body from potential harm.
The basic structure of an antibody consists of four protein chains: two identical heavy chains and two identical light chains. These chains are held together by disulfide bonds and other non-covalent interactions, forming a Y-shaped structure.
The basic structure of an antibody consists of four protein chains: two identical heavy chains and two identical light chains. These chains are held together by disulfide bonds and other non-covalent interactions, forming a Y-shaped structure.


