采用内源荧光光谱、总自由巯基定量、非还原和还原十二烷基硫酸钠聚丙烯酰胺凝胶电泳(SDS-PAGE)以及原子力显微镜(AFM)等方法探究了 pH 值对高分子量麦谷蛋白亚基(HMW-GS)1Dx5 的 N 端结构域(1Dx5-N)聚集体形成的影响规律． 结果显示:与酸性和碱性条件下相比，中性(pH =7． 0)条件下，1Dx5-N 的荧光最大发射波长发生了蓝移，表明中性条件下 1Dx5-N 聚集程度增加;与酸性和碱性处理条件相比，中性条件下 1Dx5-N的总自由巯基含量降低，且形成了更多的二聚体和高聚体，表明中性环境更有利于 1Dx5-N 的聚集，且分子间二硫键对聚集体的形成发挥了重要作用;中性条件下形成了颗粒直径相对较大的聚集体，进一步证明了中性条件更有利于 1Dx5-N 的聚集． 从而从分子层面证明了中性条件下进行面制品加工的合理性．

By means of intrinsic fluorescence measurements,total free sulfhydryl (SH) quantitation,non-reducing and reducing SDS-PAGE analysis and AFM,the effect of pH on the forming of the N-terminal domain aggregation of high molecular weight glutenin subunits (HMW-GS) 1Dx5 (1Dx5-N) was investigated.The results show that (1) in comparison with the acidic and alkaline conditions,the maximum emission wavelength of 1Dx5-N displays a blue shift under the neutral pH condition (pH 7. 0),indicating that 1Dx5-N under the neutral pH condition has a higher degree of aggregation; (2) in comparison with the acidic and alkaline conditions,the 1Dx5-N under the neutral condition is of a lower total free sulfhydryl (SH) content with more dimers and polymers,indicating that,in the ag- gregation of 1Dx5-N,the neutral condition is more helpful and the disulfide bonds play an important role; and (3) under the neutral pH condition,the aggregation of greater particle size forms,which further proves that the neutral pH condition is superior to the acidic and alkaline conditions in terms of the aggregation of 1Dx5-N.Thus,the rationality of the flour product processing under the neutral condition is demonstrated at the molecular level.