Department of Food Science and Technology, University of Tuscia, via S. Camillo de Lellis, 01100 Viterbo, Italy.
J Agric Food Chem. 2011 Apr 13;59(7):3391-7. doi: 10.1021/jf104919v. Epub 2011 Mar 16.
The influence of potential inhibitors, naturally present in wine, on the activity of stem bromelain was investigated in order to evaluate the applicability of this enzyme for protein stabilization in white wine. Bromelain proteolytic activity was tested against a synthetic substrate (Bz-Phe-Val-Arg-pNA) in a model wine system after adding ethanol, sulfur dioxide (SO(2)), skin, seed, and gallic and ellagic tannins at the average range of their concentration in wine. All the inhibitors of stem bromelain activity tested turned out to be reversible. Ethanol was a competitive inhibitor with a rather limited effect. Gallic and ellagic tannins have no inhibitory effect on stem bromelain activity, while both seed and skin tannins were uncompetitive inhibitors. The strongest inhibition effect was revealed for sulfur dioxide, which was a mixed-type inhibitor for the enzyme activity. This study provides useful information relative to a future biotechnological application of stem bromelain in winemaking.
为了评估该酶在稳定白葡萄酒蛋白方面的适用性，研究了潜在抑制剂（葡萄酒中天然存在）对菠萝蛋白酶活性的影响。在添加乙醇、二氧化硫（SO2）、果皮、种子以及没食子酸和鞣花酸单宁至相当于葡萄酒中平均浓度的模型葡萄酒体系中，用合成底物（Bz-Phe-Val-Arg-pNA）测试了菠萝蛋白酶的蛋白水解活性。结果表明，所有测试的菠萝蛋白酶抑制剂均为可逆抑制剂。乙醇为竞争性抑制剂，其抑制效果有限。没食子酸和鞣花酸单宁对菠萝蛋白酶活性无抑制作用，而种子和果皮单宁则为非竞争性抑制剂。对酶活性的抑制作用最强的是二氧化硫，其为该酶的混合型抑制剂。本研究为菠萝蛋白酶在酿酒中的未来生物技术应用提供了有用信息。
