糖尿病人血清的表面增强拉曼光谱

研究了糖尿病人和正常人血清的表面增强拉曼光谱。糖尿病人血清中蛋白质主链酰胺Ⅱ的C—N伸缩振动的谱线位移到1 585 cm-1,相对强度增加了14%，酰胺Ⅵ的谱线593 cm-1相对强度减少了33%。蛋白质侧链色氨酸吲哚环 “埋藏式”的谱线1 368 cm-1位移到“暴露式”的1 365 cm-1,且相对强度减少了59%；侧链C—S键的扭曲构象的谱线635 cm-1相对强度减少了15%，而反式构象的谱线725 cm-1增加了58%, 说明C—S键的扭曲构象部分转变为反式构象，表明糖尿病人血清中蛋白质的有序结构发生变化；类脂物特征峰1 449 cm-1相对强度增加了58%，与糖类有关的特征峰谱线1 331，1 099和740 cm-1相对强度分别增加了35%，100％和62%, 从而表明糖尿病人血清中与脂类和糖蛋白有关的物质含量增加。上述拉曼特征峰为糖尿病的诊断以及生化机理研究提供了有力的实验依据。

SERS Spectra of Serum from Diabetic

The SERS spectra were measured from normal and the diabetic serum. In the diabetic serum, the band of amide II shifted to 1 585 cm-1 and the relative intensity increased 14%, while the relative intensity of 593 cm-1 which belongs to amide Ⅵ reduced 33%. For the protein side chain, the band at 1 368 cm-1 assigned to the “buried” tryptophan shifted to 1 365 cm-1 of the “exposed” and the relative intensity reduced 59%. The relative intensity of 635 cm-1 assigned to the gauche conformation of the C—S decrased 15% and the band at 725 cm-1 increased 58%. These indicate that the structure of the protein changed in the diabetic serum. The relative intensity at 1 449 cm-1 assigned to the lipids characteristic increased 58%. The relative intensity of the glucide characteristic at 1 331, 1 099 and 740 cm-1 increased 35%, 100% and 62%, respectively. So it is indicated that the content of lipids, glucide and protein increased in diabetic. These results may offer a powerful experimental basis for diabetes diagnosis and biochemistry mechanism study.