School of Physical Sciences, Swami Ramanand Teerth Marathwada University, Nanded, Maharashtra, India.
Department of Physical Sciences, Kakatiya Institute of Technology and Science, Warangal, Telangana State, India.
J Biomol Struct Dyn. 2023 Dec;41(20):10690-10701. doi: 10.1080/07391102.2022.2157877. Epub 2022 Dec 23.
Physical, chemical and microbiological stability of the materials is affected by the rotational and translational mobility of free and hydrated water. The role of water in areas such as protein hydration and enzyme activity, food technology, lyophilization and polymers hydration is, therefore, important and can be well understood in terms of dielectric relaxation spectroscopy. Concentration and temperature-dependent hydrophobicity of amino acid is reflected in their tendencies to appear in appropriate positions in proteins. Therefore, to gain more insights on the temperature and concentration dependence of hydrophobicity and structural properties of amino acid, dielectric relaxation of aqueous alanine have been studied in the temperature region 303.15 K to 278.15 K. Time domain spectroscopy have been used in the frequency range of 10 MHz to 30 GHz and in the concentration range 0.18708 ≤ /M ≤ 0.74831. Two relaxation processes namely the low-frequency relaxation () and the high-frequency relaxation () has been detected for the aqueous alanine. Dielectric parameters such as static dielectric constant (), relaxation time () dipole moments () and correlation factor () have been studied to investigate molecular interaction between alanine and water. The number of water molecules irrotationally bond by the solute molecules () was also determined to examine the hydrophobicity of alanine which was found more hydrophobic towards low temperatures and concentrations. Thermodynamic parameters calculated are also supported well for the hydrophobic behaviour of alanine towards low temperatures and concentrations.Communicated by Ramaswamy H. Sarma.
物理、化学和微生物稳定性会受到游离水和水合水的旋转和平移流动性的影响。水在蛋白质水合和酶活性、食品技术、冷冻干燥和聚合物水合等领域的作用非常重要，而介电弛豫光谱技术可以很好地理解这一点。氨基酸的浓度和温度依赖性疏水性反映在它们在蛋白质中出现的适当位置的趋势上。因此，为了更深入地了解氨基酸疏水性和结构性质对温度和浓度的依赖性，我们研究了水合丙氨酸在 303.15 K 至 278.15 K 的温度范围内的介电弛豫。我们在 10 MHz 至 30 GHz 的频率范围内和 0.18708 ≤ /M ≤ 0.74831 的浓度范围内使用了时域光谱技术。对于水合丙氨酸，我们检测到了两个弛豫过程，即低频弛豫（）和高频弛豫（）。我们研究了介电参数，如静态介电常数（）、弛豫时间（）、偶极矩（）和相关因子（），以研究丙氨酸与水之间的分子相互作用。我们还确定了溶质分子无规结合的水分子数（），以检验丙氨酸的疏水性，结果表明丙氨酸在低温和低浓度时更疏水。计算出的热力学参数也很好地支持了丙氨酸在低温和低浓度时的疏水性行为。由 Ramaswamy H. Sarma 传达。
