Study On The Interaction Between N-confused Porphyrin Derivatives And Bovine Serum Albumin By Molecular Spectroscopy

Serum albumin （SA） is the most abundant and important protein in thecirculatory system, which is primarily responsible for the transport, distribution andcombined with all kinds of endogenous and exogenous ligands, maintain normalmetabolism and plays an important role in life activities. N-confused porphyrin （NCP）as one isomer of porphyrin, due to its pyrrole ring inversion outwards, a carbon atomand three nitrogen atoms located in the center of the ring, results in the decrease of thesymmetry, thus has unique tautomeric properties, making it become research focus inthe field of biological materials and medicine synthesis. In the thesis, we study theinteraction of several N-confused porphyrin derivatives and bovine serum albumin（BSA） by spectral method. The main contents are as follows:The intermolecular interaction between three novel type of NCP derivatives（NCP-EDA、 NCP-HCS、 NCP-MSZ） and BSA has been investigated throughfluorescence and ultraviolet spectroscopy under imitated physiological conditions.The results showed that the fluorescence of BSA was quenched by NCP derivativesthrough a combined quenching （static and dynamic） procedure and there existednon-radiative energy transfer between BSA and NCP derivatives.A strong bindingability consist in the intermolecular interaction between BSA and NCP derivatives.Nevertheless, as the change of temperature, the change trend of the binding abilitywill be slightly different. Through the analysis of thermodynamic parameters, themain forces of BSA between NCP-EDA and NCP-MSZ were performed for thehydrophobic effect, while electrostatic attraction played an important role in theinteraction between BSA and NCP-HCS. Synchronous fluorescence showed NCPderivatives can alter the polarity of the microenvironment at tryptophan residues inBSA, which affect the conformation of BSA. At the same time, the investigationconfirmed that the metal ions (Cu²⁺, Mg²⁺, Ca²⁺, Ni²⁺) for the binding ability of NCP derivatives···BSA has certain influence.This thesis through to study the interaction of several N-confused porphyrinderivatives and bovine serum albumin makes us had more in-depth understanding forthe interaction mechanism between small drug molecules and proteins upon themolecular level, at the same time for N-confused porphyrin with its structuralcharacteristics in the field of drug synthesis research provides reference information.