Department of Chemistry, Himachal Pradesh University, Summer Hill, Shimla 171005, India.
Department of Chemistry, College of Science and Arts, Promising Centre for Sensors and Electronic Devices (PCSED), Najran University, Najran 11001, Saudi Arabia.
Molecules. 2022 Nov 4;27(21):7561. doi: 10.3390/molecules27217561.
The present work deals with the micellar state study of sodium cholate and sodium deoxycholate in the aqueous solution of a bioactive peptide, namely glycyl dipeptide, having different concentrations through conductivity and fluorescence methods at different temperatures. The data obtained from conductivity is plotted against the concentration of Bile salts, and (critical micelle concentration) values are calculated. The results realized have been elucidated with reference to Glycyl dipeptide-bile salts hydrophobic/hydrophilic interactions existing in solution. In addition, the values converted to mole fraction (Xcmc) values have been used to evaluate the standard thermodynamic factors of micellization viz., enthalpy H, free energy ΔGm0, and entropy (ΔSm0) which extract information regarding thermodynamic feasibility of micellar state, energy alteration, and the assorted interactions established in the existing (bile salts-water-glycyl dipeptide) system. Furthermore, the pyrene fluorescence spectrum has also been utilized to study the change in micro polarity induced by the interactions of bile salts with glycyl dipeptide and the aggregation action of bile salts. The decrease in modification in the ratio of intensities of first and third peaks i.e., (I/I) for the pyrene molecules in aqueous bile salts solution by the addition of dipeptide, demonstrates that the micelle polarity is affected by glycyl dipeptide. This ratio has also been utilized to determine values for the studied system, and the results have been found to be in good correlation with observations made in conductivity studies.
本工作通过电导和荧光法研究了在不同温度下，生物活性肽甘氨酰二肽存在于水相中时，胆酸钠和脱氧胆酸钠的胶束状态。通过电导法得到的数据与胆盐浓度作图，并计算出（临界胶束浓度）值。结果与溶液中甘氨酰二肽-胆盐的疏水/亲水相互作用有关。此外，转化为摩尔分数（Xcmc）值的 值用于评估胶束化的标准热力学因素，即焓 H、自由能 ΔGm0 和熵（ΔSm0），这些因素提供了关于胶束状态热力学可行性、能量变化以及在现有（胆盐-水-甘氨酰二肽）系统中建立的各种相互作用的信息。此外，还利用芘荧光光谱研究了胆盐与甘氨酰二肽相互作用引起的微极性变化以及胆盐的聚集作用。随着二肽的加入，水相胆盐溶液中芘分子的第一和第三峰强度比（I/I）的变化表明，胶束的极性受到甘氨酰二肽的影响。该比值也用于确定研究体系的 值，结果与电导研究中的观察结果非常吻合。
