The Sm antigen is part of the spliceosomal complex catalyzing the splicing of nuclear pre-mRNA. Each spliceosome snRNP consists of snRNAs (U1, U2, U4/U6, and U5) bound to a unique set of proteins as well as a shared set of seven different Sm proteins with molecular weights between 9 and 29.5 kDa (typically SmB/SmB, SmD1, SmD2, SmD3, SmE, SmF, SmG). Most frequently the SmB and SmD polypeptides are targets of the anti-Sm specific autoimmune response, of which SmD is regarded the most SLE-specific Sm antigen.
Sm (non recombinant; bovine) from DIARECT is purified from bovine tissue.
系统性红斑狼疮(Systemic Lupus Erythematosus; SLE)是一种以免疫调节障碍为特征的自身免疫性疾病,会引起抗核抗体的产生、循环免疫复合物的再生,并且能激活补体系统。
抗Sm抗体是系统性红斑狼疮的高特异性抗体,所以被美国风湿病学会的分类标准收录。5-30%的SLE患者中存在抗Sm抗体,出现的频率随检测系统和研究组的择入标准而不同。研究同样指出抗Sm抗体的发生率存在种族差异。
Sm抗原是剪接体复合物的一部分,催化核mRNA前体的剪接。每个剪接体snRNP包含的snRNAs (U1, U2, U4/U6和U5)结合一组独特的蛋白质,共享一套七个不同的Sm蛋白(SmB/SmB, SmD1, SmD2, SmD3, SmE, SmF和SmG),它们分子量在9到29,5kDa之间。SmB和SmD多肽是最常见的抗Sm特异性自身免疫应答标靶,其中SmD被看作是最主要的SLE特异性的Sm抗原。
除了重组SmD蛋白(在精氨酸上SmD1和SmD3对称二甲基化)以外,Diarect现在还提供牛源的Sm抗原(非重组)。DIARECT生产的Sm(非重组,牛)是从牛组织中纯化的。