Studies On The Interaction Between Hemoglobin And Small Molecule By Molecular Spectrometry

Protein molecule is one of the largest components in organism in addition towater content. It is closely related to life and life activities. Whether drugs or poison,these biological molecules can react with proteins. They affect the metabolism of thebody. The interaction between proteins and small molecular structure analogues helpsto understand the metabolism, pharmacology and toxicology research of smallmolecules in the body. At the same time, it can provide valuable information in thedesign and selection of small molecule drugs considering the different functionalgroup effect.Based on hemoglobin (Hb) macromolecule, DDB and its structure analogues,five kinds of alkaloids, FNC, four kinds of triphenylmethane dyes and neutral redsmall molecules as the research object, this paper studied the interaction ofmacromolecular and small molecular using fluorescence spectrometry, uv-visabsorption spectroscopy and molecular simulation technology. Results show that thesefive kinds of substances can cause Hb fluorescence quenching, and quenchingmechanism is static quenching. The association constants of these structuralanalogues and Hb are different due to the difference of their functional groups.Among DDB and its analogues the binding constant of DDB is the biggest, andanalogue (III) is the smallest. Among five kinds of alkaloids the binding constant ofaminophylline is the biggest, and diprophylline is the smallest. Association constantof FNC and BHb is bigger than HHb. Among four triphenylmethane dyes the bindingconstant of bromopyrogallol red is the biggest, and bromocresol green is the smallest.The interaction forces are Van der Waals force and hydrogen bond in FNC-HHbsysterm. Hydrophobic and electrostatic interaction played a major role in othersysterm.The bonding distance between five kinds of material and Hb is less than8nm,which indicates that the energy transfer from Hb to small molecular occurs. Uv-visabsorption spectra, synchronous and three-dimensional fluorescence spectrometryshow that five kinds of material make Hb’s conformation change. Molecularsimulation results show that the binding sites of different structural analogues in Hbare different, which are close to that obtained by mentioned experimental method.