Investigation On Recognition And Mechanism Between Several Functional Molecules And Cyclodextrin/Enzyme

This paper contains two parts: spectrofluorimetry study on the chiral recognition of dansyl- amino acid by CDs; and spectroscopic study on the recognition mechanism between MMP-16 and flavonoids.L-DS/DL-DS could interact withβ-CD or 2-diTe-CD's hydrophobic cave tightly. The introduction of tellurium make the interaction capacity of CD improved greatly in comparison to naturalβ-CD, while no obvious binding between L-DS/DL-DS and 2-diSe-CD. This difference is mainly come the difference in molecular radius between selenium and tellurium, and the bridge binding length of the dimer, which is critical to the binding ability with subject molecule. The binding constant of L-DP/2-diTe-CD and D-DP/2-diTe-CD are 1.03×104 M-1 and 2.77×103 M-1, respectively, resulting a rather distinct chiral discrimination ratio of KL/KD = 3.7. This is a rather high result for the chiral recognition between the amino acid and its derivatives, which makes 2-diTe-CD a potemtial candidate in the chiral recognition and separation.Acting on a broad spectrum of extracellular, intracellular, and membrane-associated substrates, the matrix metalloproteinases (MMPs) are critical to the biological processes of organisms, and when aberrantly expressed, many pathological conditions may be born or exacerbated. Several natural flavonoids have been used as the inhibitors of MMP-16, and the fluorometric titration spectra were performed to reveal the recognition and inhibition mechanism between them. The binding constant of myricetin and MMP-16 is 6.3×1014 M-2, the ratio is 1:2; The binding constant of quercetin and MMP-16 is 3.6×107 M-1, the ratio is 1:1; The binding constant of EGCG and MMP-16 is 9.5×104 M-1/2, the ratio is 2:1.