基于曲线拟合的形态相似鹅膏菌的傅里叶变换红外光谱研究

Studies on Similar Amanita Mushrooms by Fourier Transform Infrared Spectroscopy Based on Curve-fitting Analysis

利用傅里叶变换红外光谱仪测试了形态相似的灰疣鹅膏菌、灰绒鹅膏菌和灰褶鹅膏菌的光谱,结果显示,它们的傅里叶变换红外光谱主要由蛋白质和多糖的振动吸收带组成,其蛋白质的吸收频率略有差。选择酰胺I带(中心频率1647cm-1)进行傅里叶自去卷积和曲线拟合处理后3种鹅膏菌中蛋白质在酰胺I带的吸收峰都由12个子峰叠加而成,其中在无序(1650cm-1)、α螺旋(1658cm-1)和β转角结构(1666cm-1)的振动吸收峰上,灰褶鹅膏菌吸收峰的面积百分比分别是20.98%、4.47%和17.14%,明显地区别于其它两种鹅膏菌(灰疣鹅膏菌:10.26%、12.58%和7.71%;灰绒鹅膏菌:14.33%、9.76%和8.83%)。在1683cm-1处的β转角吸收峰上,灰绒鹅膏菌吸收峰的面积百分比是1.92%,明显小于其它两种鹅膏菌(灰疣鹅膏菌:8.03%;灰褶鹅膏菌:6.65%)。研究表明:傅里叶变换红外光谱技术能提供大型真菌所含蛋白质二级结构信息。

Fourier transform infrared （FTIR） spectroscopy was used for obtaining vibrational spectra of Amanita griseoverrucosa, Amanita griseofarinosa and Arnanita griseofolia, which have similar modality. The results show that the infrared absorption spectrum is mainly composed of the absorption of protein and polysaccharide. There are some differences at the infrared absorption bands of protein among the three species of Amanita mushrooms, so the original FTIR spectra of amide Ⅰ （centered at 1647 cm^-1 ） were selected for decomposition and curver-fitting analysis, the results show the amide Ⅰ regions comprises twelve sub-bands in the infrared absorption spectra of Amanita mushrooms. The ratios of relative areas of the bands at unordered （ 1650 cm^- 1 ）, a-helix （ 1658 cm^-1 ） and β-turn （ 1666 cm^-1 ） are 20.98%, 4.47 % and 17.14% in the spectrum of Amanita griseofolia respectively, it is distinguished from the other two species evidently（Amanita griseoverrucosa： 10.26%, 12.58% and 7.71%, Amanita griseofarinosa： 14.33% , 9.76% and 8.83% ）. The ratio of relative area of the band at β-sheet （1683 cm^-1） is 1.92% in the spectrum of Amanita griseofarinosa, which is less than the other species of Amanita mushroom （Amanita griseoverrucosa： 8.03%, Amanita griseofolia： 6.65% ）. FTIR spectroscopy can provide valuable information about the protein secondary structures of fungi.