Effects of tea polyphenols on the activities of soybean trypsin inhibitors and trypsin

Huihua Huang, Kin Chor Kwok, Hanhua Liang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

35 Citations (Scopus)

Abstract

Tea polyphenols (TPs) and other materials were extracted from Chinese green tea, and their effects on trypsin inhibitors and trypsin were analysed. TPs were found to have a deactivation effect on both Kunitz trypsin inhibitor (KTI) and Bowman-Birk trypsin inhibitor (BBTI). KTI was more easily deactivated than BBTI by complexing with TPs. The deactivation effect of TPs on KTI and BBTI reached a maximum at a TP/KTI ratio of 25 and a TP/BBTI ratio of 16. However, the deactivation effect of TPs on KTI and BBTI was reduced dramatically when KTI and BBTI were already complexed with trypsin. TPs were also found to inhibit trypsin. The inhibitory activity of TPs, KTI and BBTI on trypsin was found to decrease in the order BBTI 〉 KTI 〉 TPs. Complete inhibition of trypsin by TPs could not be achieved. When the TP concentration was increased to about 17 μg ml-1, the residual activity of trypsin was maintained at 400 TU mg-1, equivalent to 32% of the initial trypsin activity. In TP inhibition the KMvalue for trypsin remained unchanged at 5.88 × 10-4mol l-1and Vmaxdecreased when benzoyl-DL-arginine-p-nitroanilide (BAPNA) was used as substrate. The pattern of trypsin inhibition by TPs is non-competitive.
Original languageEnglish
Pages (from-to)121-126
Number of pages6
JournalJournal of the Science of Food and Agriculture
Volume84
Issue number2
DOIs
Publication statusPublished - 30 Jan 2004

Keywords

  • Deactivation
  • Tea polyphenols
  • Trypsin
  • Trypsin inhibitor

ASJC Scopus subject areas

  • Biotechnology
  • Food Science
  • Agronomy and Crop Science
  • Nutrition and Dietetics

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