Stewart G R, Zhu Y, Parredes W, Tree T I, Guderian R, Bradley J E
Department of Biology, Imperial College, London, United Kingdom.
Infect Immun. 1997 Jan;65(1):164-70. doi: 10.1128/iai.65.1.164-170.1997.
The cDNA sequence encoding an Onchocerca volvulus collagen, Ovcol-1, has been isolated and the corresponding native antigen has been identified. The cDNA encodes an open reading frame of 96 amino acid residues containing an uninterrupted 66-residue Gly-X-Y repeat triple-helical (TH) domain (where X and Y may be any amino acids) flanked by a 26-residue amino non-TH domain and a 4-residue carboxyl non-TH domain. The size (9.7 kDa) and structure of the deduced molecule are unique among previously identified collagen chains. This novel collagen type has been designated "mini-chain collagen." Native Ovcol-1 is aqueous soluble and resolves by sodium dodecyl sulfate-polyacrylamide gel electrophoresis at 14.2 kDa under reducing conditions. Immunoelectron microscopy of adult female O. volvulus localized Ovcol-1 to the cuticles of both the adult worm and uterine microfilaria. A group of individuals from an area in Ecuador where O. volvulus is hyperendemic have been classified as putatively immune (PI) to O. volvulus infection. Analysis of the humoral immune responses to Ovcol-1 demonstrated that immunoglobulin G3 (IgG3) of PI individuals preferentially recognized this antigen in comparison to IgG3 of infected individuals.
编码旋盘尾丝虫胶原蛋白Ovcol-1的cDNA序列已被分离出来，并且相应的天然抗原也已被鉴定。该cDNA编码一个由96个氨基酸残基组成的开放阅读框，其中包含一个由66个残基组成的不间断的Gly-X-Y重复三螺旋（TH）结构域（其中X和Y可以是任何氨基酸），两侧分别是一个由26个残基组成的氨基非TH结构域和一个由4个残基组成的羧基非TH结构域。推导分子的大小（9.7 kDa）和结构在先前鉴定的胶原链中是独特的。这种新型胶原类型被命名为“微型链胶原蛋白”。天然的Ovcol-1可溶于水，在还原条件下通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳显示其大小为14.2 kDa。对成年雌性旋盘尾丝虫进行免疫电子显微镜检查，结果显示Ovcol-1定位于成虫和子宫微丝蚴的角质层。来自厄瓜多尔一个旋盘尾丝虫高度流行地区的一组个体已被归类为对旋盘尾丝虫感染具有推定免疫力（PI）。对Ovcol-1的体液免疫反应分析表明，与受感染个体的IgG3相比，PI个体的免疫球蛋白G3（IgG3）优先识别这种抗原。
