Toole J J, Pittman D D, Orr E C, Murtha P, Wasley L C, Kaufman R J
Proc Natl Acad Sci U S A. 1986 Aug;83(16):5939-42. doi: 10.1073/pnas.83.16.5939.
Factor VIII (antihemophilic factor) is a high molecular weight plasma glycoprotein that participates in the blood clotting cascade. The recent cloning and sequence analysis of the cDNA encoding human factor VIII revealed an obvious domain structure for the protein, which can be represented as A1-A2-B-A3-C1-C2. We now report the DNA sequence analysis of porcine exons encoding the entire B domain and part of the A2 and A3 domains. We found an unusually high degree of porcine-human amino acid sequence divergence in the B region compared with the limited sequence available for other regions of the porcine factor VIII molecule. In addition to sequence divergence, there are numerous gaps in the porcine B domain totalling over 200 amino acids. Recombinant DNA techniques were used to effect the removal of large segments of DNA encoding the B domain from the full-length human factor VIII cDNA. These constructs directed the synthesis of biologically active factor VIII when introduced into mammalian cells despite the deletion of up to 38% of the factor VIII molecule.
凝血因子VIII（抗血友病因子）是一种高分子量血浆糖蛋白，参与血液凝固级联反应。最近对编码人凝血因子VIII的cDNA进行的克隆和序列分析揭示了该蛋白明显的结构域结构，可表示为A1-A2-B-A3-C1-C2。我们现在报告猪外显子的DNA序列分析，这些外显子编码整个B结构域以及部分A2和A3结构域。我们发现，与猪凝血因子VIII分子其他区域有限的可用序列相比，B区域猪与人的氨基酸序列差异程度异常高。除了序列差异外，猪B结构域还有许多缺口，总共超过200个氨基酸。利用重组DNA技术从全长人凝血因子VIII cDNA中去除编码B结构域的大片段DNA。尽管缺失了高达38%的凝血因子VIII分子，但这些构建体在引入哺乳动物细胞时仍能指导合成具有生物活性的凝血因子VIII。
