IgSF molecules are found in most cell types and are present across taxonomic boundaries
Antibodies are Proteins that Recognize Specific Antigens 抗体能够特异性的识别抗原
Immunoglobulin Structure-Function Relationship
• Cell surface antigen receptor on B cells
B 细胞表面受体和分泌的抗体 Allows B cells to sense their antigenic environment Connects extracellular space with intracellular signalling machinery
特点是其双硫键，连接了110个氨基酸）.
Ig gene superfamily - IgSF
The genes encoding Ig domains are not restricted to Ig genes.
Although first discovered in immunoglobulins, they are found in a superfamily of related genes, particularly those encoding proteins crucial to cell-cell interactions and molecular recognition systems.
免疫球蛋白的结构与功能的关系
Epitopes（抗原决定簇 ）: Antigen Regions that Interact with Antibodies
结构域源于一个原始基因，复制，多元化，修饰等） • Ig domains are not restricted to immunoglobulins （Ig 结构域不仅 仅局限于免疫球蛋白）.
• The most striking characteristic of the Ig domain is a disulphide bond - linked structure of 110 amino acids long（Ig结构域最明显的
• Structural conservation and infinite variability - domain structure（结构 上不仅保守而且无限可变的）. • The Immunoglobulin Gene Superfamily （免疫球蛋白的超家族） • The immunoglobulin fold （免疫球蛋白的折叠） • Framework and complementarity determining regions - hypervariable
loops （框架结构和可变区） • Modes of interactions with antigens （与抗原相互作用的模型） • Effector mechanisms and isotype – role of the Fc. （Fc 区的作用） • Multimeric antibodies and multimerisation • Characteristics and properties of each Ig isotype • Ig receptors and their functions
• whilst simultaneously recognising an infinite array of antigenic determinants. （同时能够识别无限抗原族）
Immunoglobulin domains
• Structural conservation and a capacity for infinite variability in a single molecule is provided by a DOMAIN structure. （结构上不仅保守而且无限可变的- 抗体结构域）
• Secreted antibody （抗体）
Neutralisation （中和作用） Arming/recruiting effector cells （激活或者诱导功能细） Complement fixation （帮助机体对抗原的清除）
Immunoglobulins are Bifunctional Proteins
• Ig domains are derived from a single ancestral gene that has duplicated, diversified and been modified to endow an assortment of functional qualities on a common basic structure（Ig
• Immunoglobulins must interact with a small number of specialised molecules - （免疫球蛋白必须与特殊分子相互作用）
Fc receptors on cells （细胞表面的Fc受体） Complement proteins （辅助蛋白） Intracellular cell signalling molecules （细胞内信号转导分子）
Immunoglobulin StructureFunction Relationship
免疫球蛋白的结构与功能的关系
Immunoglobulin Structure-Function Relationship
• Signalling antigen receptors on B cells - bifunctional antigen-binding secreted molecules（B 细胞表面受体和分泌的抗体）