Key Laboratory of Theoretical Chemistry and Molecular Simulation of Ministry of Education, Hunan Province College Key Laboratory of QSAR/QSPR, School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2012 Aug;94:23-9. doi: 10.1016/j.saa.2012.03.050. Epub 2012 Mar 29.
Spiro pyrrolidines, which were proved with diverse and potent biological activities and they were discovered widespread in nature. In this paper, using fluorescence and ultraviolet spectroscopy, we investigated the interactions between novel spiro pyrrolidine (NSP) and bovine serum albumin (BSA) under the imitated physiological condition. The results show that the NSP binds to BSA molecules. Static quenching and non-radiation energy transfer are the main reasons for fluorescence quenching. We calculated the binding constant (K(a)) and binding sites (n) at different temperatures and obtained the binding distance between the tryptophan residue in BSA and the NSP based on the Förster theory of non-radiation energy transfer. In addition, using synchronous fluorescence spectra, we demonstrated conformation changes of BSA caused by NSP. The comparison of binding potency of NSP and BSA suggests that the substituent on the benzene ring influences the binding ability of NSP and BSA.
螺吡咯烷类化合物具有多样而强效的生物活性，广泛存在于自然界中。本文采用荧光光谱法和紫外光谱法，在模拟生理条件下，研究了新型螺吡咯烷（NSP）与牛血清白蛋白（BSA）之间的相互作用。结果表明，NSP 与 BSA 分子发生结合。静态猝灭和非辐射能量转移是荧光猝灭的主要原因。我们在不同温度下计算了结合常数（K(a)）和结合位点数（n），并根据福斯特非辐射能量转移理论，得到了 BSA 中色氨酸残基与 NSP 之间的结合距离。此外，通过同步荧光光谱，我们证明了 NSP 引起的 BSA 构象变化。NSP 和 BSA 结合能力的比较表明，苯环上的取代基影响 NSP 与 BSA 的结合能力。
