Matsushita Misao, Fujita Teizo
Department of Biochemistry, Fukushima Medical University, Japan.
Immunobiology. 2002 Sep;205(4-5):490-7. doi: 10.1078/0171-2985-00149.
Ficolins are a group of proteins containing both a collagen-like domain and a fibrinogen-like domain and are found in varying tissues. Ficolins present in sera have a lectin activity toward N-acetylglucosamine through their fibrinogen-like domains. The domain organizations between ficolins and mannose-binding lectin (MBL) are very similar in that both consist of a collagen-like domain and a carbohydrate-binding domain, although their carbohydrate-binding moieties are different. MBL acts as an opsonin and activates complement in association with MBL-associated serine proteases (MASPs) and sMAP, truncated protein of MASP-2, via the lectin pathway. Like MBL, two types of human serum ficolins, L-ficolin/P35 and H-ficolin, are associated with MASPs and sMAP, and activate the lectin pathway. In addition, L-ficolin/P35 acts as an opsonin. These findings indicate that serum ficolins play an important a role in innate immunity in a similar manner to MBL.
纤维胶凝蛋白是一类包含胶原样结构域和纤维蛋白原样结构域的蛋白质，存在于多种组织中。血清中的纤维胶凝蛋白通过其纤维蛋白原样结构域对N - 乙酰葡糖胺具有凝集素活性。纤维胶凝蛋白和甘露糖结合凝集素（MBL）之间的结构域组织非常相似，两者都由一个胶原样结构域和一个碳水化合物结合结构域组成，尽管它们的碳水化合物结合部分不同。MBL作为一种调理素，通过凝集素途径与MBL相关丝氨酸蛋白酶（MASP）和sMAP（MASP - 2的截短蛋白）协同激活补体。与MBL一样，两种类型的人血清纤维胶凝蛋白，即L - 纤维胶凝蛋白/P35和H - 纤维胶凝蛋白，与MASP和sMAP相关，并激活凝集素途径。此外，L - 纤维胶凝蛋白/P35还作为一种调理素。这些发现表明，血清纤维胶凝蛋白在固有免疫中发挥着与MBL类似的重要作用。
