菜籽多肽结构鉴定及其包封β-胡萝卜素的机制

Identification of rapeseed peptides and its encapsulation mechanism onβ-carotene

为了探索菜籽多肽包封β-胡萝卜素的相互作用机制,该研究以经超滤(1~3 kDa)和乙腈先后处理的菜籽多肽为研究对象,采用液质联用技术鉴定了菜籽多肽的氨基酸序列,筛选出一些具有典型特征结构的多肽,并通过分子对接技术分析菜籽多肽包封β-胡萝卜素相互作用机制。结果表明,菜籽多肽大多来源于油菜籽中主要的储藏蛋白Cruciferin和Napin,部分来源于油料蛋白Oleosins;分子对接结果揭示,β-胡萝卜素端链上的2,6,6-三甲基环己烯基主要与多肽中的谷氨酰胺、缬氨酸、脯氨酸和异亮氨酸等氨基酸产生疏水相互作用;筛选出的2条菜籽多肽GFRDMHQKVE和NTGDQPLVII的包封率和负载量分别为93.17%和0.56 mg/mg,95.70%和0.57 mg/mg,均具有良好的包封效果。该研究为菜籽多肽包封β-胡萝卜素等疏水性生物活性物质提供了理论依据。

To explore the interaction mechanism between rapeseed peptides and β-carotene, the amino acid sequences of rapeseed peptides successively treated by ultrafiltration(1-3 kDa) and acetonitrile were identified by LC-MS/MS, and some peptides with typical structures were selected. Furthermore, the interaction mechanism between rapeseed peptides and β-carotene were analyzed by molecular docking. The results showed that most of the rapeseed peptides were derived from Cruciferin and Napin, the major storage proteins in rapeseed and some rapeseed peptides were derived from Oleosins, the oilseed protein in rapeseed. Molecular docking data revealed that the 2, 6, 6-trimethylcyclohexene group on the tail chain of β-carotene mainly produced hydrophobic interactions with amino acids such as Gln, Val, Pro and Ile from rapeseed peptides. The encapsulation efficiency and loading amount of two selected polypeptides(GFRDMHQKVE and NTGDQPLVII) were 93.17% and 0.56 mg/mg, 95.70% and 0.57 mg/mg, respectively, which have excellent encapsulation effects. The present study provides a theoretical basis for rapeseed peptides to encapsulate β-carotene and other hydrophobic bioactive molecules.