绿色木霉产双功能酶二级结构的FT—IR光谱法分析

摘要

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.%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％。