Ye Feng, An Ying-ge, Qin De-zhi, Yang Lin, She Lan, Xing Rui-min
College of Chemistry and Environmental Science, Henan Normal University, Xinxiang 453007, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2007 Feb;27(2):321-4.
The effect of crystallization of hydroxyapatite on the secondary structure of bovine serum albumin (BSA) was studied by circular dichroism spectrum, Fourier transform infrared spectroscopy, derivative, deconvolution and curve-fitting techniques in the present paper. The CD results show that pure bovine serum albumin is composed of 56.8% alpha-helices, 5.8% beta-sheets, 14.1% beta-turns and 23.9% random structures, while the bovine serum albumin in the Ca10(PO4)6(OH)2/bovine serum albumin solution is composed of 25.4% alpha-helices, 25.0% beta-sheets, 20.0% beta-turns and 29.7% random structures. The results of Fourier transform infrared spectroscopy are in good agreement with those from the CD spectra. From these results it can be seen that the percentage of alpha-helix decreased, while that of the beta-sheet increased with the formation of the crystal of hydroxyapatite, and with the reaction time increasing, the percentages of alpha-helix obviously dropped and those of beta-sheet markedly rose. These results showed that alpha-helix transformed into beta-sheet. Furthermore the essence of these changes is discussed.
本文采用圆二色光谱、傅里叶变换红外光谱、导数、去卷积和曲线拟合技术研究了羟基磷灰石结晶对牛血清白蛋白（BSA）二级结构的影响。圆二色光谱结果表明，纯牛血清白蛋白由56.8%的α-螺旋、5.8%的β-折叠、14.1%的β-转角和23.9%的无规结构组成，而在Ca10(PO4)6(OH)2/牛血清白蛋白溶液中的牛血清白蛋白由25.4%的α-螺旋、25.0%的β-折叠、20.0%的β-转角和29.7%的无规结构组成。傅里叶变换红外光谱的结果与圆二色光谱的结果高度一致。从这些结果可以看出，随着羟基磷灰石晶体的形成，α-螺旋的百分比降低，而β-折叠的百分比增加，并且随着反应时间的增加，α-螺旋的百分比明显下降，β-折叠的百分比显著上升。这些结果表明α-螺旋转变为β-折叠。此外，还对这些变化的本质进行了讨论。
