How the silkworm spins out such an excellent silk fiber has been a hot topic. The issue here is to know how the coil chains in the gland of silkworm transform to β sheet in silk fiber. We used the regenerated silk fi...How the silkworm spins out such an excellent silk fiber has been a hot topic. The issue here is to know how the coil chains in the gland of silkworm transform to β sheet in silk fiber. We used the regenerated silk fibroin to imitate the silk fibroin of the gland to investigate the effect of metal ion(Ca 2+ . Cu 2+ ) on the silk spinning process of Bombyx mori silkworm. The solutions or gel obtained from hte mixture of regenerated silk fibroin and metal ions were dried for mimicking the gradual loss of water in the spinning process. The 13 C NMR spectrum simulation for C β nucleus of alanine quantitatively demonstrated that the conformation of the regenerated silk fibroin is dominantly of silk Ⅰ, whereas the fibroin with metal ions has more silk Ⅱ conformation. Raman spectroscopies show the consistent results with that of NMR. The binding of metal ion with carbonyl and amide in protein backbone allows the protein chain to array regularly, therefore leading to the β sheet formation.展开更多
用质子激发 X 线荧光分析方法(PIXE)测定了大骨节病病区和非病区的水、粮以及用该水粮喂养的大白鼠的肋软骨和硬骨中22种化学元素的含量。结果发现水粮中存在差异的元素反应在用该水粮喂养的大白鼠的骨、软骨中也存在差异,含量都低的元...用质子激发 X 线荧光分析方法(PIXE)测定了大骨节病病区和非病区的水、粮以及用该水粮喂养的大白鼠的肋软骨和硬骨中22种化学元素的含量。结果发现水粮中存在差异的元素反应在用该水粮喂养的大白鼠的骨、软骨中也存在差异,含量都低的元素有 P、Mn、Cu、As、Zn。都高的有铅。其中锌低在水、粮、硬骨和软骨中都完全一致呈非常显著性差异(p<0.01)。提示病区水、粮中化学元素对骨质的影响不是单一元素缺乏或过多所致,而是多种元素的复合因素。展开更多
文摘How the silkworm spins out such an excellent silk fiber has been a hot topic. The issue here is to know how the coil chains in the gland of silkworm transform to β sheet in silk fiber. We used the regenerated silk fibroin to imitate the silk fibroin of the gland to investigate the effect of metal ion(Ca 2+ . Cu 2+ ) on the silk spinning process of Bombyx mori silkworm. The solutions or gel obtained from hte mixture of regenerated silk fibroin and metal ions were dried for mimicking the gradual loss of water in the spinning process. The 13 C NMR spectrum simulation for C β nucleus of alanine quantitatively demonstrated that the conformation of the regenerated silk fibroin is dominantly of silk Ⅰ, whereas the fibroin with metal ions has more silk Ⅱ conformation. Raman spectroscopies show the consistent results with that of NMR. The binding of metal ion with carbonyl and amide in protein backbone allows the protein chain to array regularly, therefore leading to the β sheet formation.
文摘用质子激发 X 线荧光分析方法(PIXE)测定了大骨节病病区和非病区的水、粮以及用该水粮喂养的大白鼠的肋软骨和硬骨中22种化学元素的含量。结果发现水粮中存在差异的元素反应在用该水粮喂养的大白鼠的骨、软骨中也存在差异,含量都低的元素有 P、Mn、Cu、As、Zn。都高的有铅。其中锌低在水、粮、硬骨和软骨中都完全一致呈非常显著性差异(p<0.01)。提示病区水、粮中化学元素对骨质的影响不是单一元素缺乏或过多所致,而是多种元素的复合因素。
