Abstract:Our previous studies had suggested that the intercellular signal molecule might be an important target of electromagnetic fields. Insulin, an intercellule signal molecule, plays a critical role in transferring life information. The studies on effects of pulsed electric fields (PEF) on insulin molecule are meaningful for explaining the mechanism of biological effects of electromagnetic fields. The PEF, which we used, with its highest electric field (2×106 V·m-1) coupled into the insulin buffer, was about 1 V·cm-1cm, with a repeating frequency of 50 Hz. In the present study, the changes of insulin conformation induced by PEF were studied by fluorescence spectroscopy. Insulin solution was exposed to 50 Hz PEF with different electric field intensities for 5-35 min, which caused a time-and dose-dependent decrease in fluorescence intensities of insulin. Further, insulin solution was exposed to PEF at different temperatures to investigate the effects of PEF co-operated with temperature on insulin. The results indicated that the difference in temperature (about 5 ℃) could induce conflict results,which is due to the effects of PEF co-operated with temperature rather than only to the effect of temperature. The authors calculated that the increase in temperature induced by PEF was 0.07 ℃ (less than 0.1 ℃). So the effects of PEF were scarcely explained by thermal effects, it belongs to “non-thermal effects” of electric fields. So it was concluded that temperature is a considerably important factor in “non-thermal effects” of electric fields, and the ignorance of variety of temperature probably result in the contrary conclusion. Further, Raman spectroscopy was used to investigate the details of structure of insulin treated by PEF co-operated with temperature. The results of Raman spectroscopy verified the effects of PEF co-operated with temperature on insulin. And the reductions of the S—S band intensity at 510 cm-1, the skeletal C—C stretch band intensity at 934 cm-1, and the content of the secondary structure of the alpha helix were observed. Both S—S linkages and alpha helix structure were important to the stabilization of insulin conformation. Modification of insulin may change the biological activity either by reducing the affinity of the hormone for the receptor or by decreasing the ability of the complex, when formed, to elicit a biological response.
Key words:Pulsed electric field;Temperature;Insulin;Fluorescence spectroscopy;Raman spectroscopy
严喆,陈树德*,乔登江. 温度与电磁参数协同影响胰岛素分子构象与功能的光谱学方法研究[J]. 光谱学与光谱分析, 2008, 28(06): 1343-1347.
YAN Zhe,CHEN Shu-de*,QIAO Deng-jiang. Study on Temperature & EMF Co-Effects on Insulin Conformation and Biological Functions by Fluorescence and Raman Spectroscopy. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2008, 28(06): 1343-1347.
[1] Wertheimer N, Leeper E. American Journal of Epidemiology, 1979, 109(3): 273. [2] Verkasalo P K, Pukkala E, Hongisto M Y, et al. Br. Med. J., 1993, 307: 895. [3] Feychting M, Forssen U, Floderus B. Epidemiology, 1997, 8(4): 384. [4] Simko M, Kriehuber R, Lange S. Mutat. Res., 1998, 418: 101. [5] Maes A, Collier M, Vandoninck S, et al. Bioelectromagnetics, 2000, 21(8): 589. [6] Zeni O, Bersani F, Scarfi M R. Radiation Environmental Biophysics, 2002, 41(3): 275. [7] LIN Fan(林 凡). High Power Microwave Technology(高功率微波技术), 2003, 11: 8. [8] DAI Yu-wen, DING Li-ping, LI Le-jun, et al(戴雩文, 丁荔萍, 李乐军, 等). Journal of East China Normal University(Natural Science)(华东师范大学学报·自然科学版),2004, (4): 56. [9] LI Le-jun, DAI Yu-wen, XIA Ruo-hong, et al(李乐军,戴雩文,夏若虹,等). Bioelectromagnetics(生物电磁学), 2005, 8: 639. [10] PENG Meng-yong, CHEN Shu-de, QIAO Deng-jiang, et al(彭梦勇,陈树德,乔登江, 等). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2002, 22(6): 879. [11] CHENG Ji-ji(程极济). Light Biophysics(光生物物理学). Beijing: Higher Education Press(北京:高等教育出版社), 1988. 120. [12] Nai-Teng Yu, Liu C S, Shea D C O’. J. Mol. Biol., 1972, 70(1-2): 117. [13] Reipa V, Gaigals A, Abramowitz S. J. Electroanal. Chem., 1993, 348: 413. [14] Tu A T. Raman Spectroscopy in Biology: Prinoiples and Application. John Wiley & Sons, Inc. 1982, 65. [15] Robert W Williams. J. Mol. Biol., 1983, 166: 581. [16] Robert W Williams, Duker A. J. Mol. Biol., 1981, 152: 783. [17] Rober Winker, Sabine Ivancsits, Alexander Pilger, et al. Mutat. Res., 2005, 585: 43. [18] Maria Rosaria Scarfi, Anna Sannino, Alessandro Perrotta, et al. Radiat. Res., 2005, 164: 270.