龋齿是一种慢性破坏性疾病,基质金属蛋白酶-2(MMP-2)在龋齿中起主要作用。茶黄素的抑制机制[茶黄素(TF1),茶黄素-3-没食子酸酯(TF2A),茶黄素-3没食子酸酯(TF2B),使用酶抑制动力学等技术研究了茶黄素-3,3'-二油酸酯(TF3)]对MMP-2的作用,多光谱方法,分子对接,和分子动力学模拟。结果表明,TF1、TF2A、TF2B,和TF3都竞争性和可逆地抑制MMP-2活性。荧光光谱和分子对接表明,四种茶黄素通过非共价相互作用自发结合MMP-2,由氢键和疏水相互作用驱动,构成静态猝灭机制,并导致MMP-2周围的色氨酸残基环境发生变化。分子动力学模拟表明,四种茶黄素可以形成稳定的,与MMP-2的紧密复合物。此外,发现茶黄素抑制MMP-2的能力顺序为TF1>TF2B>TF2A>TF3。有趣的是,MMP-2与TF1、TF2A、TF2B,TF3与抑制能力的顺序一致,与茶黄素的位阻顺序相反。这可能是由于MMP-2的活动口袋空间狭窄,茶黄素的空间位阻越小,越容易进入活性口袋并与MMP-2结合。这项研究为茶黄素作为天然MMP-2抑制剂的探索中的功能成分提供了新的见解。
Dental caries is a chronic and destructive disease and matrix metalloproteinase-2 (MMP-2) plays a major role in caries. The inhibitory mechanisms of theaflavins [theaflavin (TF1), theaflavin-3-gallate (TF2A), theaflavin-3\'-gallate (TF2B), and theaflavin-3,3\'-digallate (TF3)] on MMP-2 were investigated using techniques such as enzyme inhibition kinetics, multi-spectral methods, molecular docking, and molecular dynamics simulations. The results showed that TF1, TF2A, TF2B, and TF3 all competitively and reversibly inhibited MMP-2 activity. Fluorescence spectra and molecular docking indicated that four theaflavins spontaneously bind to MMP-2 through noncovalent interactions, driven by hydrogen bonds and hydrophobic interactions, constituting a static quenching mechanism and resulting in an altered tryptophan residue environment around MMP-2. Molecular dynamic simulations demonstrated that four theaflavins can form stable, compact complexes with MMP-2. In addition, the order of theaflavins\' ability to inhibit MMP-2 was found to be TF1 > TF2B > TF2A > TF3. Interestingly, the order of binding capacity between MMP-2 and TF1, TF2A, TF2B, and TF3 was consistent with the order of inhibitory capacity, and was opposite to the order of steric hindrance of theaflavins. This may be due to the narrow space of the active pocket of MMP-2, and the smaller the steric hindrance of theaflavins, the easier it is to enter the active pocket and bind to MMP-2. This study provided novel insights into theaflavins as functional components in the exploration of natural MMP-2 inhibitors.