Department of Physics and Biophysics, Faculty of Food Science and Nutrition, Poznan University of Life Sciences, Wojska Polskiego 38/42, 60-637 Poznan, Poland.
Department of Food Quality and Safety Management, Faculty of Food Science and Nutrition, Poznan University of Life Sciences, Wojska Polskiego 31/33, 60-637 Poznan, Poland.
Molecules. 2021 May 11;26(10):2851. doi: 10.3390/molecules26102851.
Steady-state emission spectroscopy of 1-anilino-8- naphthalene sulfonate (ANS) and 1,6-diphenyl-1,3,5-hexatriene (DPH), fluorescence anisotropy, and DSC methods were used to characterize the interactions of the newly synthesized 1-carba-alpha-tocopherol (CT) with a 1,2-dipalmitoyl--glycero-3-phosphocholine (DPPC) membrane. The DSC results showed significant perturbations in the DPPC structure for CT concentrations as low as 2 mol%. The main phase transition peak was broadened and shifted to lower temperatures in a concentration-dependent manner, and pretransition was abolished. Increasing CT concentrations induced the formation of new phases in the DPPC structure, leading to melting at lower temperatures and, finally, disruption of the ordered DPPC structure. Hydration and structural changes of the DPPC liposomes using ANS and DPH fluorescent probes, which are selectively located at different places in the bilayer, were studied. With the increased concentration of CT molecules in the DPPC liposomes, structural changes with the simultaneous formation of different phases of such mixture were observed. Temperature studies of such mixtures revealed a decrease in the temperature of the main phase transition and fluidization at decreasing temperatures related to increasing hydration in the bilayer. Contour plots obtained from concentration-temperature data with fluorescent probes allowed for identification of different phases, such as gel, ordered liquid, disordered liquid, and liquid crystalline phases. The CT molecule with a modified chromanol ring embedded in the bilayer led to H-bonding interactions, expelling water molecules from the interphase, thus introducing disorder and structural changes to the highly ordered gel phase.
采用稳态荧光发射光谱法、荧光各向异性法和差示扫描量热法（DSC）研究了新型 1-碳-α-生育酚（CT）与 1,2-二棕榈酰基-sn-甘油-3-磷酸胆碱（DPPC）膜相互作用。结果表明，当 CT 浓度低至 2mol%时，DPPC 结构就会发生显著变化。主相变峰随着浓度的增加而变宽并向低温移动，同时预相变峰消失。随着 CT 浓度的增加，DPPC 结构中形成了新的相，导致更低的温度下发生熔融，最终破坏 DPPC 结构的有序性。使用 ANS 和 DPH 荧光探针研究了 DPPC 脂质体的水合作用和结构变化，这两种探针分别位于双层膜的不同位置。随着 DPPC 脂质体中 CT 分子浓度的增加，观察到结构发生变化，同时形成了这种混合物的不同相。对这些混合物的温度研究表明，主相变温度降低，在降低温度时发生流体化，这与双层膜中水合作用的增加有关。荧光探针的浓度-温度数据的等高线图允许识别不同的相，如凝胶相、有序液相、无序液相和液晶相。CT 分子的铬醇环结构经过修饰后嵌入双层膜中，导致氢键相互作用，将水分子从界面排出，从而使高度有序的凝胶相产生无序和结构变化。
