有机酸脱酰胺改性小麦面筋蛋白聚集态与脱酰胺速率相互关系及构效关系的研究

The objective of this work is to investigate the influences of aggregation state of wheat gluten to carboxylic acid deamidation upon hydrothermal treatment (CDHT). Based on our previously work, effect of aggregation extent of native/modified protein solution to deamidation rate and the functionalities of modified protein will be further evaluated by fully monitoring and characterizing the aggregation state of wheat gluten during CDHT. Changes in the immunoreactivity of celiac IgA anti-gliadin antibodies to the corresponding modified proteins will be studied. The relationship of aggregation state and bioactivity of modified protein molecules will be investigated. A regulation and simulation model for this self-assemble aggregation of wheat gluten through CDHT will be proposed by the means of coarse-grained molecular dynamics simulation and artificial neural network statistical correlation. The anti-modified parts of wheat gluten, in together with the effect of starch to the deamidation efficiency of wheat gluten, will be characterized. This work will complete the mechanism responsible for the aggregation of cereal protein through carboxylic acid deamidation. It will figure out bottleneck problems in related fields, such as the low productivity of modified cereal protein, the significant anti-modified resistance, unclear impact factors and unclear structure-activity relationship. It will have important information for summarizing and designing the orientation-control modification of proteins, as well as further improving the quality of modified cereal proteins.

本项目将在前期研究的基础上，从小麦面筋蛋白聚集态结构出发，全程监控和表征改性前、中、后小麦面筋蛋白分子聚集态，分析原始和改性小麦面筋蛋白分子缠绕程度对蛋白脱酰胺程度、功能特性和对肠胃抗醇溶免疫球蛋白抗体的免疫活性的影响，阐明体系改性蛋白伸展折叠与聚集对脱酰胺速率的内在关系，明确其构效关系，同时运用粗粒化分子动力学模拟和人工神经网络统计学相关性分析方法，构建调控和模拟体系大分子自组装聚集模型，并研究小麦蛋白难改性的因子分子聚集特征以及淀粉在小麦面筋蛋白脱酰胺改性的影响。本课题将完善小麦面筋蛋白在有机酸脱酰胺改性过程中的聚集机制，揭示有机酸脱酰胺改善小麦面筋蛋白功能和生物活性的原因，解决改性小麦面筋蛋白制备效率低、影响因素复杂不明确、构效关系不明确等小麦面筋蛋白深加工遇到的基础理论问题，对指导改性谷物蛋白的研究和开发及其利用，总结出定向控制谷物蛋白改性技术和提高改性蛋白质量具有重要的意义。

有机酸湿热脱酰胺是现今小麦面筋蛋白改性中最热的方法，本研究从小麦面筋蛋白聚集态结构出发，从高分子流变学标尺行为的角度，全程监控和表征改性前、中、后小麦面筋蛋白分子聚集态，分析原始和改性小麦面筋蛋白分子缠绕程度对蛋白脱酰胺程度、功能特性和结构特征的影响，阐明体系改性蛋白伸展折叠与聚集对脱酰胺速率的内在关系，明确其构效关系，并研究小麦蛋白难改性的因子分子聚集特征以及淀粉在小麦面筋蛋白脱酰胺改性的影响。研究发现了有机酸水热小麦面筋蛋白高分子溶液体系“初始决定态理论”，认为蛋白原始的聚集形态是决定分子结构伸展程度和脱酰胺改变趋势的最重要因素，提出40%的脱酰胺程度是脱酰胺体系小麦面筋蛋白蛋白分子聚集结构和功能特性最优化的平衡点和最佳平衡态，高热（>90 ºC）和过低酸(>3.14 × 10-3 mol/L)的方式不利于构建最优最平衡的控制途径。并首次发现了淀粉酶酶解后不溶性小麦蛋白和不溶沉淀中的麦谷蛋白组分酶解敏感性和淀粉酶处理后不溶沉淀中的醇溶蛋白组分分子作用力敏感性，说明淀粉和醇溶蛋白独特紧密的糖蛋白结构复合体系的存在性，提出淀粉是小麦蛋白溶解的主要阻力，并提出新的理论模型明晰淀粉、麦谷蛋白和麦醇溶蛋白的相互关系和结构特征。