Circular dichroism spectral studies on the recombinant human neuroglobin  

作　　者：ZHAO Chao LI Lianzhi WANG Li JI Haiwei 

机构地区：[1]School of Chemistry and Chemical Engineering, Liaocheng University,Liaocheng 252059, China [2]State Key-Laboratory of Coordination Chemistry, Nanjing University,Nanjing 210093, China

出　　处：《Chinese Science Bulletin》2006年第21期2581-2585,共5页

基　　金：This work was supported by the National Natural Science Foundation of China(Grant No.20471025).

摘　　要：Neuroglobin (NGB) is a newly discov- ered member of the hemoglobin superfamily that is primarily expressed in the brain of humans and other vertebrates. The effects of protein concentration, solvent, pH and temperature on the secondary structure of NGB were investigated by employing far UV circular dichroism (CD) spectroscopy. The results show that NGB exists mainly in α-helix form when its concentration is less than 10 μmol/L. However, its α-helix content decreases with the increase of con- centration in the range of 10―40 μmol/L and remains unchanged when the concentration is higher than 40 μmol/L, which suggest that NGBs form intermolecular disulfide bond and aggregate in higher concentration. The α-helix content of NGB in methanol and ethanol is a little higher than that in water, indicating a higher stability of NGB in these solvents. NGB loses its α-helical secondary structure in either acidic or alka- line solution to some extent. Although increased temperature destabilizes the α-helices of NGB, over 16% of α-helices can be kept at 110°C. Therefore, NGB is a protein with hyperthermal stability.Neuroglobin （NGB） is a newly discovered member of the hemoglobin superfamily that is primarily expressed in the brain of humans and other vertebrates. The effects of protein concentration, solvent, pH and temperature on the secondary structure of NGB were investigated by employing far UV circular dichroism （CD） spectroscopy. The results show that NGB exists mainly in α-helix form when its concentration is less than 10μmol/L. However, its α-helix content decreases with the increase of concentration in the range of 10--40 μmol/L and remains unchanged when the concentration is higher than 40 μmol/L, which suggest that NGBs form intermolecular disulfide bond and aggregate in higher concentration. The α-helix content of NGB in methanol and ethanol is a little higher than that in water, indicating a higher stability of NGB in these solvents. NGB loses its α-helical secondary structure in either acidic or alkaline solution to some extent. Although increased temperature destabilizes the α-helices of NGB, over 16% of α-helices can be kept at 110℃. Therefore, NGB is a protein with hyperthermal stability.

关 键 词：血红蛋白 脊椎动物 CD光谱 二级结构 稳定性 

分 类 号：Q51[生物学—生物化学]