Inhibition of Pancreatic Elastase by Polyphenolic Compounds

详细信息    查看全文

• 作者：Natrcia F. Brs ; Rui Gonalves ; Nuno Mateus ; Pedro A. Fernandes ; Maria Joo Ramos ; Victor de Freitas
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2010
• 出版时间：October 13, 2010
• 年：2010
• 卷：58
• 期：19
• 页码：10668-10676
• 全文大小：1045K
• 年卷期：v.58,no.19(October 13, 2010)
• ISSN：1520-5118

文摘

Polyphenols are plant secondary metabolites commonly present in the human diet that possess the ability to bind and inhibit digestive proteins. In the present study, kinetic measurements of porcine pancreatic elastase (PPE) activity were determined using Suc-(Ala)₃-p-nitroanilide as substrate and polyphenolic compounds as inhibitors. A positive relationship between the degree of polyphenol polymerization and the capacity of the polyphenols to inhibit PPE was observed. Procyanidins with a molecular weight of at least 1154 Da were necessary to observe a significant inhibitory ability. Kinetic parameters were also calculated and confirmed that the inhibition is reversible and competitive. Molecular docking and dynamics simulations demonstrated that the tetramer structure has a higher affinity to the enzyme due the establishment of more contact points with the amino acids present in its active site. Hydrogen bond interactions and hydrophobic effects established between the polyphenol groups and the side chain of residues stabilize and favor the binding mode of this procyanidin. This work is relevant to the study of the antinutritional effects caused by dietary tannins on the digestive enzymes’ activity, reducing food digestibility and the absorption of nutrients. In general, the elastase model studied herein allows a better understanding of the inhibitory ability of polyphenol compounds.

Keywords:

Procyanidins; pancreatic elastase; antinutritional effect; competitive inhibitor; binding free energy