Centro de Investigação em Química, Departamento de Química, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto, Portugal.
J Agric Food Chem. 2010 Nov 24;58(22):11901-6. doi: 10.1021/jf103026x. Epub 2010 Oct 28.
The interactions between porcine pancreatic lipase (PL) and grape seed procyanidins were studied by an enzymatic assay, fluorescence quenching, nephelometry, and dynamic light scattering (DLS). An inhibitory effect of grape seed procyanidins on lipase hydrolytic activity was found. Both the inhibition of lipase activity by procyanidins and the respective quenching of intrinsic protein fluorescence increased with the average degree of polymerization of the tested procyanidins. The association between procyanidins and enzyme involves a specific interaction as inferred from the fluorescence assays despite not changing significantly the tertiary structure of the protein. For all tested procyanidins it was shown, both by DLS and by nephelometry, that an increase in aggregation occurs up to a stoichiometric maximum after which further procyanidin addition causes a decrease in aggregation of aggregates. The maximum size of aggregates was shown to be closely related to the maximum overall aggregation. It was also shown that the inhibition of enzyme activity is to a large extent independent of the formation of aggregates.
通过酶促测定、荧光猝灭、光散射和动态光散射（DLS）研究了猪胰脂肪酶（PL）与葡萄籽原花青素之间的相互作用。发现葡萄籽原花青素对脂肪酶水解活性有抑制作用。原花青素对脂肪酶活性的抑制作用以及蛋白质内源荧光的各自猝灭作用均随测试原花青素的平均聚合度而增加。尽管荧光分析并未显著改变蛋白质的三级结构，但原花青素与酶之间的结合涉及特异性相互作用。对于所有测试的原花青素，均通过 DLS 和光散射表明，在达到化学计量最大值后，聚集物的聚集程度会增加，之后进一步添加原花青素会导致聚集物的聚集减少。聚集物的最大尺寸与总体聚集的最大程度密切相关。还表明，酶活性的抑制在很大程度上与聚集体的形成无关。
