花生品种缺失过敏蛋白的筛选和品种间过敏原性的比较

本文研究了56个花生品种中8种主要过敏蛋白及其过敏原性的差异,为低致敏性花生的育种和消费提供支持。收集了33个中国花生品种和23个日本花生品种并统一种植,收获后进行花生品种间的致敏性差异性研究。利用聚丙烯酰胺凝胶电泳和凝胶成像系统分析了花生主要过敏原的种类和含量,用免疫印迹和间接ELISA方法测定各花生品种的致敏蛋白及其过敏原性。结果发现,过敏原Ara h 1在56个品种中的相对含量最高,其次是Ara h 2(20 kDa)和Ara h 3(14 kDa)。中国花生品种中绥中大花生和沭阳大站秧缺失过敏蛋白Ara h 3(35 kDa),新金伏大、兴城大花生和如东碗儿青缺失过敏蛋白Ara h 3(24 kDa),日本花生品种JP-16与JP-19中过敏蛋白Ara h 3(24 kDa)缺失。用中国花生过敏患者的血清进行间接ELISA试验,发现中国花生的过敏原性较日本花生强,这可能与所用的血清来源于中国病人有关。中国花生品种中致敏性最低的是铁岭四粒红,最高的是营口四粒红。日本花生品种中JP-10的致敏性最强,JP-6的致敏性最低。决定花生的致敏性强弱的因素复杂,单纯过敏条带的缺失或含量高低和花生致敏性并不存在线性关系。

大豆过敏原在低盐固态酱油酿造过程中的降解规律

为研发低致敏酱油,探究了低盐固态酱油酿造过程中大豆蛋白致敏原的变化规律。在建立实验室的模拟低盐固态酱油酿造的基础上,采集大豆未经处理、高压灭菌(121℃,8 min)、制曲阶段(44 h)、发酵阶段(30 d)、灭菌前和灭菌后等样品,利用聚丙烯酰胺凝胶电泳法(SDS-PAGE)测定酿造过程中蛋白的组成变化,用兔抗大豆多克隆抗体进行酶联免疫试验和免疫印迹实验分析发酵过程中大豆致敏原抗原性变化,用过敏病人血清进行酶联免疫试验测定大豆致敏原过敏原性变化。结果表明,经高压蒸煮、制曲、发酵和加热灭菌后,原料中的大豆蛋白条带减少或消失,其中制曲变化的最大。β-伴大豆球蛋白的α、α′亚基和大豆球蛋白的酸性亚基分别在制曲阶段开始降解,β-伴大豆球蛋白的β亚基及大豆球蛋白酸性亚基在制曲之后消失,大豆球蛋白的碱性亚基在整个酿造阶段变化不大。免疫印迹结果显示相同的结果,酿造过程中大豆过敏原的过敏性和抗原性逐渐降低,在发酵30 d后的生酱油中仍能在检测到大豆球蛋白,在灭菌后也没有完全降解,但是这些残留的大豆致敏原没有检测到IgE结合能力。酶联免疫试验结果表明,和原材料大豆相比,样品中的抗原性在经过4个酿造阶段高压蒸煮、制曲、发酵和加热灭菌之后分别下降了8.13%、39.00%、69.10%和87.06%,过敏原性分别下降了8.92%、71.66%、92.26%、98.45%。在酱油酿造过程中大豆致敏原逐步降解,制曲阶段对大豆致敏原的降解最大。酱油中仍残留有大豆球蛋白,但是没有检测残留蛋白的致敏性。

Toxicological Evaluation of Chicken-Breast Meat with High-Dose Irradiation

In this paper, toxicity and safety of high-dose irradiated chicken-breast meat were evaluated. For assays of acute toxicity, genetic toxicity, and sub-chronic toxicity, ames test, mice bone marrow erythrocyte micronucleus, and mice sperm abnormality were performed. The results showed that, in the acute oral toxicity tests, median lethal dose （more than 10 000 mg kg-~） in male and female ICR mice showed no toxicological signs. For subacute 30-d oral toxicology of irradiated chicken-breast meat with dose of 10, 15 and 25 kGy in both male and female SD rats, no noticeable toxicological effects were observed. It is concluded that chicken-breast meat with high-dose irradiation has no acute toxicity and no genotoxicity, nor harmful effects on the animal body at the tested dosage range. Therefore, high-dose irradiated chicken-breast meat is safe for pet consumption.

Proteomic analysis of pathogen-responsive proteins from maize stem apoplast triggered by Fusarium verticillioides

During the attack of a pathogen, a variety of defense-associated proteins are released by the host plant in the apoplast to impede the perceived attack. This study utilized the mass spectrometry(LC-MS/MS) and label-free quantification method to analyze the apoplastic fluid(APF) from maize stalk and identified the proteins responsive to the Fusarium verticillioides infection. We have identified 742 proteins, and among these, 119 proteins were differentially accumulated(DAPs), i.e., 35 up-regulated, 18 down-regulated, and 66 proteins were only induced by the pathogen infection. The differentially accumulated proteins were analyzed for their Gene Ontology(GO) and Kyoto Encyclopedia of Gene and Genomes(KEGG) pathway enrichment. The highly enriched Biological Process(BP) term was the L-serine biosynthesis process, whereas the most enriched Molecular Function(MF) term was the cysteine-type endopeptidase inhibitor activity. It was also found that the pathways related to the biosynthesis of amino acid, biosynthesis of secondary metabolites, protein processing in the endoplasmic reticulum, and carbohydrate metabolic pathways were significantly enriched. Moreover, 61 out of 119 differentially accumulated proteins were predicted as secretory proteins. The secretory pathways analysis showed that a greater number of proteins were secreted through the conventional secretion system compared to the unconventional secretion system. The identified secreted proteins were related to a variety of pathways in defense responses including cell redox homeostasis, cell wall modification, signal transduction, carbohydrate metabolism, binding proteins(metal ion binding, RNA binding and heme-binding), maintenance and stabilization of other proteins, indicating a complex response from the plant to the fungal infection. Our data suggested that a number of host proteins belonging to various pathways have been modulated in the apoplastic region.