S/R两种构型尼古丁与溶菌酶作用机理的研究

Study on the interaction mechanism between S/R -nicotine and lysozyme

利用分子光谱法和计算机模拟技术,探究了S/R两种构型尼古丁与溶菌酶的结合作用机理。研究结果显示,S构型和R构型均以静态猝灭方式猝灭溶菌酶的荧光,且可以自发地与溶菌酶结合,氢键和范德华力是维系结合的主要作用力。不同的是,虽然S/R两种构型尼古丁与溶菌酶均有一个主要的结合位点,但R构型结合能力远强于S构型;两种构型均可以使溶菌酶的二级结构发生变化,诱导其Trp和Tyr残基周围微环境变化,但R构型尼古丁的影响更为显著。本研究结果,对评估尼古丁对口腔环境的影响具有指导意义,并对其安全性评价提供一定参考。

The mechanism of the interaction between S/R -nicotine and lysozyme were explored through molecular spectroscopy and computer simulation techniques.The results indicated that both S -nicotine and R -nicotine quenched the fluorescence of lysozyme by a static quenching mechanism,and could spontaneously combine with lysozyme.Hydrogen bond and van der Waals force were the main forces to maintain the combination.The difference was that although there was a major binding site between S/R -nicotine and lysozyme,the binding ability of R -nicotine was much stronger than that of S -nicotine;the combination of S/R -nicotine both changed the secondary structure of lysozyme,induced changes in the microenvironment around Trp and Tyr residues,and the effect of R -nicotine was more significant.The results of this study have guiding significance forevaluating the effect of nicotine on oral environment,and provide important references for its safety evaluation.