Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh, UP, 202002, India.
Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia.
Int J Biol Macromol. 2018 Apr 1;109:1132-1139. doi: 10.1016/j.ijbiomac.2017.11.107. Epub 2017 Nov 20.
The current study comprises of an inclusive biophysical study, enlightening the binding of L-3, 4-dihydroxyphenylalanine (l-Dopa) with human lysozyme (HL) and hen egg white lysozyme (HEWL). Spectroscopic and molecular docking tools have been utilized to study the interaction of l-Dopa with both HL and HEWL. Spectrofluorimetric measurements exhibited that l-Dopa quenched the HL and HEWL intrinsic fluorescence. A binding constant (K) of ∼10M for both HL and HEWL was obtained, asserting a significant binding. Negative value of ΔG affirmed that the reaction between proteins and l-Dopa was spontaneous. Far-UV CD spectra revealed a boost to the proteins helical content in the presence of l-Dopa. Furthermore, DLS measurements displayed the decrease in hydrodynamic radii (R) of HL and HEWL in the presence of l-Dopa. Molecular docking studies established that l-Dopa formed complexes with both the proteins through hydrogen bonding and hydrophobic interaction. The present study characterizing the l-Dopa interaction with lysozyme could be noteworthy in realizing both pharmaco-dynamics and/or -kinetics of drugs used in various diseases.
本研究包含一个综合的生物物理研究，阐明了 L-3,4-二羟基苯丙氨酸（L-Dopa）与人溶菌酶（HL）和鸡卵清溶菌酶（HEWL）的结合。本研究利用光谱和分子对接工具来研究 L-Dopa 与 HL 和 HEWL 的相互作用。荧光光谱测量表明，L-Dopa 猝灭了 HL 和 HEWL 的内源荧光。对于 HL 和 HEWL，均获得了约 10M 的结合常数（K），表明存在显著的结合。ΔG 的负值证实了蛋白质与 L-Dopa 之间的反应是自发的。远紫外 CD 光谱表明，在 L-Dopa 存在下，蛋白质的螺旋含量增加。此外，DLS 测量显示，在 L-Dopa 存在下，HL 和 HEWL 的流体力学半径（R）减小。分子对接研究表明，L-Dopa 通过氢键和疏水相互作用与两种蛋白质形成复合物。本研究对 L-Dopa 与溶菌酶相互作用的特性进行了描述，这对于理解用于各种疾病的药物的药代动力学和/或药效动力学可能具有重要意义。
