采用傅里叶红外光谱(FT—IR)的酰胺I带和酰胺III带测定绿色木霉产双功能壳聚糖酶一纤维素酶(CCBEs)的天然二级构象,结果显示:FT—IR光谱酰胺I$IIII带可以用来对绿色木霉所产的双功能酶二级结构进行预测,对两种双功能酶的主要二级结构组分α-螺旋和β-折叠的测定误差分别在2%和4%范围内,CCBEI的二级构象以β-折叠为主,高达70%,与其圆二色谱和Gamier—Robson预测结果基本一致;而CCBEII的二级构象中的β-折叠和α-螺旋含量分别为53.6%和14.6%。
The secondary structure of two bifunctional chitosanase-cellulase enzymes (CCBE I and CCBE II) from Trichoderma viride was explored by FT-IR spectroscopy. Amide I and III PT-IR bands allowed prediction of the secondary structure of CCBE. The errors of determination for α-helix and β-sheet contents in CCBEs were less than 2% and 4%, respectively. The quantitative analysis of CCBE I revealed that the amino acid sequence was consistent with the results of circular dichroism analysis and Gamier-Robson prediction. The βsheet content was approximately 70% in CCBE I, while the β-sheet and α-helix contents of CCBE II were approximately 53.6% and 14.6%, respectively. The measurement errors of α- helix and β-sheet of CCBEs were less than 2% and 4%, respectively.