Herpers Bjorn Lars, Immink Marie-Monique, de Jong Ben A W, van Velzen-Blad Heleen, de Jongh Bartelt M, van Hannen Erik J
St. Antonius Hospital Nieuwegein, Department of Medical Microbiology and Immunology, P.O. Box 2500, 3430 EM Nieuwegein, Netherlands.
Mol Immunol. 2006 Mar;43(7):851-5. doi: 10.1016/j.molimm.2005.06.035. Epub 2005 Aug 1.
Human L-ficolin (FCN) is a serum lectin characterized by a collagen-like and a fibrinogen-like domain that can activate the lectin pathway of complement. Structural and functional similarities to mannose-binding lectin (MBL) suggest a role for L-ficolin in innate immunity. Structural polymorphisms in the MBL2 gene lead to functional deficiency of MBL. Polymorphisms in the FCN2 gene have not been studied previously. We developed 10 denaturing gradient gel electrophoresis (DGGE) assays to screen a total of 188 Dutch Caucasians for polymorphisms in FCN2. Total gene screening in this large cohort revealed 10 single nucleotide polymorphisms (SNPs). Interestingly, two conserved coding SNPs were found in exon 8, leading to amino acid substitutions within the fibrinogen-like domain. Fibrinogen-like domains are highly conserved among several proteins in many species. As this domain is responsible for binding of L-ficolin, these newly found coding polymorphisms could alter the affinity of the protein for its substrates and possibly alter the ability of L-ficolin to recognize invading microorganisms.
人L-纤维胶凝蛋白（FCN）是一种血清凝集素，其特征在于具有可激活补体凝集素途径的胶原样结构域和纤维蛋白原样结构域。与甘露糖结合凝集素（MBL）的结构和功能相似性表明L-纤维胶凝蛋白在先天免疫中发挥作用。MBL2基因的结构多态性导致MBL功能缺陷。此前尚未对FCN2基因的多态性进行研究。我们开发了10种变性梯度凝胶电泳（DGGE）检测方法，以筛选总共188名荷兰白种人FCN2基因的多态性。对这个大型队列进行的全基因筛查发现了10个单核苷酸多态性（SNP）。有趣的是，在外显子8中发现了两个保守的编码SNP，导致纤维蛋白原样结构域内的氨基酸替换。纤维蛋白原样结构域在许多物种的几种蛋白质中高度保守。由于该结构域负责L-纤维胶凝蛋白的结合，这些新发现的编码多态性可能会改变该蛋白对其底物的亲和力，并可能改变L-纤维胶凝蛋白识别入侵微生物的能力。
