Characterization of Structural Change of Ascorbate Peroxidase from Chinese Kale during Denaturation by Circular Dichroism
XI Jia-fu1, TANG Lei1*, ZHANG Jian-hua2, ZHANG Hong-jian2, CHEN Xu-sheng2, MAO Zhong-gui2
1. Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China 2. School of Biotechnology, Jiangnan University, Wuxi 214122, China
Abstract：Circular dichroism (CD) is a special absorption spectrum. The secondary structure of protein such as α-helix, β-sheet and β-turn in the far ultraviolet region (190～250 nm) has a characteristic CD spectrum. In order to understand the activity and structural changes of ascorbate peroxidase from Chinese kale (BaAPX) during denaturation, specific activity and percentage of secondary structure of BaAPX under different time，temperature and concentration were analyzed by CD dynamically. In addition, the percentage of four secondary structures in BaAPX was calculated by CD analysis software Dichroweb. The results show that BaAPX is a full α-type enzyme whose specific activity is positively related to the percentage of α-helix. During denaturation of BaAPX, three kinds of structural changes were proposed: the one-step structural change from initial state (N state) to minimum state of α-helix (R state) under low concentration and low temperature; the one-step structural change from N state to equilibrium state (T state) under high concentration and low temperature; the two-step structural changes from N state through R state to final T state under heat treatment and low temperature renaturation.
席加富1，唐 蕾1*，张建华2，张宏建2，陈旭升2，毛忠贵2 . 圆二色谱表征芥蓝抗坏血酸过氧化物酶变性过程中的结构变化 [J]. 光谱学与光谱分析, 2014, 34(11): 3062-3065.
XI Jia-fu1, TANG Lei1*, ZHANG Jian-hua2, ZHANG Hong-jian2, CHEN Xu-sheng2, MAO Zhong-gui2 . Characterization of Structural Change of Ascorbate Peroxidase from Chinese Kale during Denaturation by Circular Dichroism. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2014, 34(11): 3062-3065.
