REQUIMTE, LAQV, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, s/n, 4169-007 Porto, Portugal.
VITEC, Centro Tecnológico del Vino., E 43730 Falset (Tarragona), Spain.
Food Chem. 2018 Mar 15;243:175-185. doi: 10.1016/j.foodchem.2017.09.063. Epub 2017 Sep 19.
In this work, saturation transfer difference-NMR, isothermal microcalorimetry and molecular dynamics simulations have been used to study the individual interactions between basic, glycosylated and acidic proline-rich proteins (bPRPS, gPRPs, aPRPs) and P-B peptide with some representative food tannins [procyanidin B2, procyanidin B2 3'-O-gallate (B2g) and procyanidin trimer (catechin-4-8-catechin-4-8-catechin)]. Results showed that P-B peptide was in general the salivary protein (SP) with higher affinity whereas aPRPs showed lower affinity to the studied procyanidins. Moreover, B2g was the procyanidin with higher affinity for all SP. Hydrophobic and hydrogen bonds were present in all interactions but the major driving force depended on the procyanidin-SP pair. Furthermore, proline clusters or residues in their vicinity were identified as the probable sites of proteins for interaction with procyanidins. For bPRP and aPRP a significant change to less extended conformations was observed, while P-B peptide did not display any structural rearrangement upon procyanidins binding.
在这项工作中，我们使用饱和转移差-NMR、等温微量热法和分子动力学模拟来研究碱性、糖基化和酸性脯氨酸丰富蛋白（bPRPS、gPRPs、aPRPs）与 P-B 肽与一些代表性食物单宁[原花青素 B2、原花青素 B2 3'-O-没食子酸酯（B2g）和原花青素三聚体（儿茶素-4-8-儿茶素-4-8-儿茶素）]之间的单独相互作用。结果表明，P-B 肽通常是唾液蛋白（SP），与研究的原花青素具有更高的亲和力，而 aPRPs 与原花青素的亲和力较低。此外，B2g 是所有 SP 中与原花青素亲和力更高的原花青素。所有相互作用中都存在疏水键和氢键，但主要驱动力取决于原花青素-SP 对。此外，脯氨酸簇或其附近的残基被确定为蛋白质与原花青素相互作用的可能部位。对于 bPRP 和 aPRP，观察到它们向不太伸展的构象发生显著变化，而 P-B 肽在与原花青素结合时没有显示出任何结构重排。
