Proteomic/peptidomic profile and <i>Escherichia coli</i> growth inhibitory effect of <i>in vitro</i> digested soya protein

Plant proteins contain bioactive peptides with functional properties and physiological activities. In the present work, the bioactive peptides produced during <i>in vitro</i> gastrointestinal digestion of soya protein isolate were investigated. Protein samples were subjected to simulated gastrointestinal digestion with a generation of permeate (&lt;3 kDa) and retentate (&gt;3 kDa) fractions. The permeate was analysed by nano-liquid chromatography electrospray ionisation tandem mass spectrometry (LC-nano ESI MS/MS) using a shotgun peptidomic approach, and the retentate was further digested with trypsin and analysed using a shotgun proteomic approach. Based on protein profile observed, the retentate was further tested for its potential antimicrobial activity by evaluating the inhibitory effect on <i>E. coli</i> growth. In the present study the peptidomic/proteomic characterisation of permeate and retentate fractions revealed the presence of bioactive peptides and proteins associated with antioxidant, ACE-inhibitory, anti-hypertensive and antimicrobial activities. The presence of potentially antimicrobial proteins in the retentate fraction is supported by a marked <i>E. coli</i> F18+ growth inhibitory activity of the same fraction. In particular, the growth inhibitory effect was significant from one until six hours of incubation with 0.65–2.6 mg/ml of <i>in vitro</i> digested soya. The obtained data confirmed that soya-based supplements may have potential beneficial effects after human consumption, and they may be re-cycled for animal nutrition in line with the circular economy concept.HighlightsSoya-based supplements are relevant sources of bioactive molecules.Soya based supplements could be re-cycled for animal feeding considering the circular economy concept. Soya-based supplements are relevant sources of bioactive molecules. Soya based supplements could be re-cycled for animal feeding considering the circular economy concept.

植物蛋白中蕴含兼具功能特性与生理活性的生物活性肽。本研究针对大豆分离蛋白经体外（in vitro）胃肠道消化过程中产生的生物活性肽展开探究。将蛋白样品实施模拟胃肠道消化，得到渗透液（<3 kDa）与截留液（>3 kDa）两个组分。采用鸟枪法肽组学分析策略，通过纳升液相色谱-电喷雾电离串联质谱（LC-nano ESI MS/MS）对渗透液进行分析；将截留液经胰蛋白酶进一步消化后，采用鸟枪法蛋白质组学分析策略开展检测。基于观测得到的蛋白谱，进一步通过评估其对大肠杆菌（E. coli）生长的抑制作用，验证截留液的潜在抗菌活性。本研究通过对渗透液与截留液组分开展肽组学/蛋白质组学表征，发现其中存在与抗氧化、血管紧张素转换酶（ACE）抑制、抗高血压及抗菌活性相关的生物活性肽与蛋白。该截留液组分对大肠杆菌F18+具有显著的生长抑制活性，这证实了其中存在潜在抗菌蛋白。具体而言，当采用0.65~2.6 mg/ml的体外消化大豆样品进行孵育时，其生长抑制作用在孵育1至6小时内均表现显著。本研究所得数据证实，大豆基补充剂在人体食用后或可产生潜在有益健康的效应，同时可按照循环经济理念回收用于动物营养领域。

研究亮点：
大豆基补充剂是生物活性分子的重要来源。
结合循环经济理念，大豆基补充剂可回收用于动物饲喂。
大豆基补充剂是生物活性分子的重要来源。
结合循环经济理念，大豆基补充剂可回收用于动物饲喂。