Wu Yushui, Tu Xiangdong, Lian Yunzong, Chen Feng, Lan Fenghua, Zhu Zhongyong
Medical Laboratory Center, Fuzhou General Hospital, Fuzhou, China.
Acta Haematol. 2006;116(2):96-100. doi: 10.1159/000093638.
We have previously reported a homozygous Cys329Gly mutation in a Chinese patient with factor VII (FVII) deficiency. Others have found a heterozygous Cys329Gly mutation in the F7 gene from patients of three different pedigrees. However, none of the reports included the expression and characterization of the mutant FVII in vitro. To investigate the effect of Cys329Gly on FVII function, we carried out transient transfections of baby hamster kidney cells (BHK-21) with a mutant FVII construct and compared the results to those obtained using a wild-type FVII construct and vector control. The results demonstrate that the level of FVII:Ag secreted into the medium by transfected BHK-21 cells with mutant construct was not affected, but the coagulation activity of the mutant FVII was undetectable. We conclude that Cys329 is critical to FVII coagulation, and the replacement of cysteine 329 by glycine leads to the loss of coagulation activity in the patients, possibly the molecular basis for FVII deficiency in the patients.
我们之前报道过一名患有凝血因子VII（FVII）缺乏症的中国患者存在纯合子Cys329Gly突变。其他人在来自三个不同家系的患者的F7基因中发现了杂合子Cys329Gly突变。然而，所有报告均未涉及突变型FVII在体外的表达和特性。为了研究Cys329Gly对FVII功能的影响，我们用突变型FVII构建体对幼仓鼠肾细胞（BHK - 21）进行了瞬时转染，并将结果与使用野生型FVII构建体和载体对照获得的结果进行比较。结果表明，用突变构建体转染的BHK - 21细胞分泌到培养基中的FVII:Ag水平未受影响，但突变型FVII的凝血活性检测不到。我们得出结论，Cys329对FVII凝血至关重要，患者中甘氨酸取代半胱氨酸329导致凝血活性丧失，这可能是患者FVII缺乏的分子基础。
