CNR-ITAE Istituto di Tecnologie Avanzate per l'Energia "Nicola Giordano", Via Salita S. Lucia Sopra Contesse 5, 98126 Messina, Italy.
Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina, V. le F. Stagno D'Alcontres, 31, 98166 Messina, Italy.
Int J Mol Sci. 2023 Jan 20;24(3):2099. doi: 10.3390/ijms24032099.
The interaction of an equilibrium mixture of monomeric and aggregated cationic -5,15-(-methylpyridinium-4-yl)-10,15--diphenylporphine (t-HPagg) chloride salt with human serum albumin (HSA) has been investigated through UV/Vis absorption, fluorescence emission, circular dichroism and resonant light scattering techniques. The spectroscopic evidence reveals that both the monomeric t-HPagg and its aggregates bind instantaneously to HSA, leading to the formation of a tight adduct in which the porphyrin is encapsulated within the protein scaffold (S) and to clusters of aggregated porphyrins in electrostatic interaction with the charged biomolecules. These latter species eventually interconvert into the final S species following pseudo-first-order kinetics. Molecular docking simulations have been performed to get some insights into the nature of the final adduct. Analogously to hemin bound to HSA, the obtained model supports favorable interactions of the porphyrin in the same 1B subdomain of the protein. Hydrophobic and van der Waals energy terms are the main contributions to the calculated ΔG value of -117.24 kcal/mol.
通过紫外/可见吸收、荧光发射、圆二色性和共振光散射技术研究了单体和聚集的阳离子-5,15-(-甲基吡啶-4-基)-10,15--二苯基卟啉（t-HPagg）氯化盐与人体血清白蛋白（HSA）的平衡混合物的相互作用。光谱证据表明，单体 t-HPagg 及其聚集体都立即与 HSA 结合，形成紧密的加合物，其中卟啉被包裹在蛋白质支架（S）内，并与带电荷的生物分子发生静电相互作用的聚集卟啉簇。这些后一种物质最终会按照准一级动力学转化为最终的 S 物质。进行了分子对接模拟以深入了解最终加合物的性质。与 HSA 结合的血红素类似，获得的模型支持卟啉在蛋白质相同的 1B 亚域中的有利相互作用。疏水和范德华能是计算得到的-117.24 kcal/mol ΔG 值的主要贡献者。
