まとめ
ラムダ2光鎖の1つのアミノ酸がグリシンからアルギニンに変化すると,その分泌が防止されます. 免疫グロブリンA (IgA) 骨髄腫細胞の変数領域におけるアルギニンに対するこのグリシン置換は,タンパク質輸出に影響を与えます.
科学分野:
- 分子生物学は分子生物学である.
- 免疫学 免疫学とは
- タンパク質生化学 タンパク質生化学
背景:
- 骨髄腫細胞系MOPC315.5を分泌するIgA (lambda 2) の2つの誘導体を研究した.
- MOPC315.26はラムダ2光鎖を分泌するが,MOPC315.37はそれを分泌しない.
- 以前の研究では,MOPC315-37のラムダ2鎖の変化が変数領域にあることが示されていました.
研究 の 目的:
- MOPC315.37.3のラムダ2光鎖の非分泌に起因する特定の分子変化を決定する.
- 単一のアミノ酸の置換がタンパク質分泌に与える影響を明らかにする.
主な方法:
- 分泌性 (MOPC315.26) と非分泌性 (MOPC315.37) のミエロマ細胞系の両方から再編成されたラムダ2遺伝子断片をクローンしました.
- クローンされたラムダ2遺伝子のヌクレオチド配列を決定した.
主要な成果:
- ラムダ2鎖のリーダーペプチドと常数領域の核酸配列は,両方の細胞系において同一であった.
- 変数領域の配列は,アミノ酸の位置15にある単一の塩基対によって異なった.
- MOPC315.26はグリシン (GGT) を含んでいるが,MOPC315.37はアルギニン (CGT) を含んでいる.
結論:
- ラムダ2光鎖の変数領域におけるアルギニン (陽性電荷) に対するグリシン (中性) の単一のアミノ酸置換は,タンパク質分泌の失敗を引き起こします.
- この発見は,タンパク質の輸送と分泌経路における特定のアミノ酸特性の重要な役割を強調しています.
関連する概念動画
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.


