產(chǎn)品編號 | bs-0474P-APC |
英文名稱 | Human IgA Native protein / APC |
中文名稱 | APC標(biāo)記的人免疫球蛋白A |
別 名 | Human IgA protein; Human IgA; Purified Human IgA; 天然人IgA蛋白/人免疫球蛋白A |
性 狀 | Liquid |
濃 度 | 1mg/ml |
保存條件 | Store at -20℃ for one year. Avoid repeated freeze/thaw cycles. |
產(chǎn)品介紹 |
Human IgA (immunoglobulin A) is a glycosylated protein of 160 kDa and is produced as a monomer or as a J chain linked dimer. Monomeric IgA constitutes 5-15 % of the serum immunoglobulins whereas dimeric IgA is localized to mucosa surfaces such as saliva, gastrointestinal secretion, bronchial fluids and milk. Mucosal IgA plays a major role in host defence by neutralising infectious agents at mucosal surfaces. The production is usually local and antigen specific IgA producing B cells can be found in regions under the lamina propria where they mature into dimeric IgA producing plasma cells. IgA deficiency is the most common immunodeficiency that may affect both serum and mucosal produced IgA. OR: The secretory component is a component of immunoglobulin A (IgA) which consists of a portion of the polymeric immunoglobulin receptor. Polymeric IgA binds to the polymeric immunoglobulin receptor on the basolateral surface of epithelial cells and is taken up into the cell via transcytosis. The receptor-IgA complex passes through the cellular compartments before being secreted on the luminal surface of the epithelial cells, still attached to the receptor. Proteolysis of the receptor occurs and the dimeric IgA molecule, along with the secretory component, are free to diffuse throughout the lumen. 血清型IgA是單體(bs-0474P),分泌型IgA是雙聚體(bs-0360P) IgA分為血清型和分泌型兩種類型 大部分血清IgA為單體,大約10%~15%為雙聚體,也發(fā)現(xiàn)少量多聚體。IgA功能區(qū)的分布與IgG十分相似,兩個亞類(IgA1和IgA2)的最大差異在鉸鏈區(qū)。IgA2缺少H-L鏈間二硫鍵區(qū)域,容易被解離分開。從含量、穩(wěn)定性和半衰期看,血清型IgA雖不如IgG,但高于其他類Ig.IgA可以結(jié)合抗原,但不能激活補體的經(jīng)典途徑,因此不能象IgG那樣發(fā)揮許多的生物效應(yīng),所以過去曾誤以為血清型IgA的意 |