Fey G, Colten H R
Fed Proc. 1981 May 15;40(7):2099-104.
Many of the serum complement components are synthesized primarily in the liver but extrahepatic synthesis in mononuclear phagocytes has been noted. This local production of complement, particularly at sites of inflammation, may be of importance in host defenses and immunopathological reactions. Recent studies of complement biosynthesis in vitro have revealed some of the genetic and microenvironmental factors that affect the rates of complement synthesis, posttranslational modification, and secretion of these proteins. The third, fourth, and fifth complement components are synthesized as single chain, procomplement proteins that require proteolytic cleavage to generate the native C4 protein is mediated by a plasmin-like enzyme. These studies, plus the most recent developments in analysis of the complement genes at a molecular level, will provide more complete understanding the mechanisms of regulation of complement production.
许多血清补体成分主要在肝脏合成，但也已注意到单核吞噬细胞可进行肝外合成。补体的这种局部产生，尤其是在炎症部位，可能在宿主防御和免疫病理反应中具有重要意义。最近在体外进行的补体生物合成研究揭示了一些影响补体合成速率、翻译后修饰以及这些蛋白质分泌的遗传和微环境因素。第三、第四和第五补体成分作为单链前补体蛋白合成，需要蛋白水解切割才能产生天然的C4蛋白，这一过程由一种类似纤溶酶的酶介导。这些研究，加上在分子水平分析补体基因的最新进展，将更全面地理解补体产生的调节机制。
