Department of Environmental, Biological and Pharmaceutical Sciences and Technologies (DiSTABiF), University of Campania 'Luigi Vanvitelli', Via Vivaldi 43, 81100 Caserta, Italy.
Department of Molecular Medicine and Medical Biotechnology, University of Naples 'Federico II', Via S. Pansini 5, 80131 Naples, Italy.
Food Chem. 2021 Apr 16;342:128337. doi: 10.1016/j.foodchem.2020.128337. Epub 2020 Oct 10.
This study investigates on the presence of toxic proteins in quinoa seeds. To this aim, a plethora of biochemical approaches were adopted for the purification and characterization of quinoin, a type 1 ribosome-inactivating protein (RIP) contained in quinoa seeds. We determined its melting temperature (68.2 ± 0.6 °C) and thermostability (loss of activity after 10-min incubation at 70 °C). Considering that quinoa seeds are used as a food, we found that quinoin is cytotoxic against BJ-5ta (human fibroblasts) and HaCaT (human keratinocytes) in a dose- and time-dependent manner. Moreover, in an in vitro digestive pepsin-trypsin treatment, 30% of quinoin is resistant to enzymatic cleavage. This toxin was found in seeds (0.23 mg/g of seeds) and in sprouted seeds obtained after 24-h (0.12 mg/g of sprout) and 48-h (0.09 mg/g of sprout). We suggest a thermal treatment of quinoa seeds before consumption in order to inactivate the toxin, particularly in sprouts, generally consumed raw.
本研究调查了藜麦种子中是否存在毒性蛋白。为此，我们采用了大量生化方法来纯化和鉴定藜麦中的 quinoin，这是一种存在于藜麦种子中的 1 型核糖体失活蛋白 (RIP)。我们测定了它的熔点（68.2±0.6°C）和热稳定性（在 70°C 下孵育 10 分钟后活性丧失）。考虑到藜麦种子被用作食物，我们发现 quinoin 以剂量和时间依赖的方式对 BJ-5ta（人成纤维细胞）和 HaCaT（人角质形成细胞）具有细胞毒性。此外，在体外消化胃蛋白酶-胰蛋白酶处理中，30%的 quinoin 能抵抗酶切。这种毒素存在于种子（0.23mg/g 种子）和发芽种子中（发芽 24 小时后为 0.12mg/g 发芽，发芽 48 小时后为 0.09mg/g 发芽）。我们建议在食用藜麦种子之前进行热处理，以灭活毒素，特别是在通常生食的豆芽中。
