Tamada Yasushi
National Institute of Agrobiological Sciences, Insect Biomaterials and Technology Department, 1-2 Owashi, Tsukuba, Ibaraki 305-8634, Japan.
Biomaterials. 2004 Feb;25(3):377-83. doi: 10.1016/s0142-9612(03)00533-7.
Silk fibroin (Bombyx mori) was sulfated using chlorosulfonic acid in pyridine. FT-IR spectra showed introduction of sulfate group by this reaction; NMR spectra indicated that sulfation occurred mainly at tyrosine and serine residues. Molecular size decreased and dispersed with sulfation. The molecular weight was estimated in around 20,000 by GPC using protein standards. Amino acid composition suggested that sulfated fibroin came from H-chain of fibroin; the crystal region of fibroin molecule remained in sulfated fibroin. The amount of sulfate groups increased with overall reaction time. The maximum amount was estimated in 1.0 mmol/g by acidimetric titration. Sulfation efficiency was calculated as 66.7%. Blood coagulation was prevented by 0.5 mg of sulfated fibroin in 1 ml of blood, while original fibroin did not show any effect. Anticoagulant activity of sulfated fibroin strongly depends on the amount of sulfate groups introduced. These results indicate that sulfate group introduction results in addition of anticoagulant function to silk fibroin. Sulfated fibroin is a new type of anticoagulant material having a protein backbone.
采用氯磺酸在吡啶中对丝素蛋白（家蚕）进行硫酸化处理。傅里叶变换红外光谱表明该反应引入了硫酸基团；核磁共振光谱表明硫酸化主要发生在酪氨酸和丝氨酸残基上。硫酸化后分子尺寸减小且分散。使用蛋白质标准品通过凝胶渗透色谱法估计分子量约为20,000。氨基酸组成表明硫酸化丝素蛋白来自丝素蛋白的重链；丝素蛋白分子的晶体区域在硫酸化丝素蛋白中保留。硫酸基团的量随总反应时间增加。通过酸碱滴定法估计最大量为1.0 mmol/g。硫酸化效率计算为66.7%。1 ml血液中0.5 mg硫酸化丝素蛋白可防止血液凝固，而原始丝素蛋白无任何作用。硫酸化丝素蛋白的抗凝活性强烈依赖于引入的硫酸基团的量。这些结果表明硫酸基团的引入导致丝素蛋白增加了抗凝功能。硫酸化丝素蛋白是一种具有蛋白质主链的新型抗凝材料。
