Division of Bioanalytical Chemistry, Office of Regulatory Science, Center for Food Safety and Applied Nutrition (CFSAN), FDA , College Park, Maryland 20740, United States.
Division of Analytical Chemistry, Office of Regulatory Science, Center for Food Safety and Applied Nutrition (CFSAN), FDA , College Park, Maryland 20740, United States.
J Agric Food Chem. 2015 Dec 9;63(48):10525-35. doi: 10.1021/acs.jafc.5b04205. Epub 2015 Nov 25.
The effectiveness of a proline endopeptidase (PEP) in hydrolyzing gluten and its putative immunopathogenic sequences was examined using antibody-based methods and mass spectrometry (MS). Based on the results of the antibody-based methods, fermentation of wheat gluten containing sorghum beer resulted in a reduction in the detectable gluten concentration. The addition of PEP further reduced the gluten concentration. Only one sandwich ELISA was able to detect the apparent low levels of gluten present in the beers. A competitive ELISA using a pepsin-trypsin hydrolysate calibrant was unreliable because the peptide profiles of the beers were inconsistent with that of the hydrolysate calibrant. Analysis by MS indicated that PEP enhanced the loss of a fragment of an immunopathogenic 33-mer peptide in the beer. However, Western blot results indicated partial resistance of the high molecular weight (HMW) glutenins to the action of PEP, questioning the ability of PEP in digesting all immunopathogenic sequences present in gluten.
采用基于抗体的方法和质谱（MS）研究了脯氨酸内肽酶（PEP）水解面筋及其潜在免疫原性序列的效果。基于基于抗体的方法的结果，含有高粱啤酒的面筋发酵导致可检测面筋浓度降低。添加 PEP 进一步降低了面筋浓度。只有一种三明治 ELISA 能够检测到啤酒中存在的明显低水平的面筋。使用胃蛋白酶-胰蛋白酶水解校准品的竞争 ELISA 不可靠，因为啤酒的肽谱与水解校准品的肽谱不一致。MS 分析表明，PEP 增强了啤酒中免疫原性 33 肽片段的丢失。然而，Western blot 结果表明高分子量（HMW）谷蛋白对 PEP 作用具有部分抗性，这质疑了 PEP 消化面筋中所有免疫原性序列的能力。
