Protein Quality & Function, Lincoln Research Centre, AgResearch, Lincoln, New Zealand.
J Sci Food Agric. 2011 Dec;91(15):2806-13. doi: 10.1002/jsfa.4525. Epub 2011 Jul 18.
Peptide and protein damage contributes to the loss of quality and value in protein-based food and textile products as well as to the degeneration of biological tissues such as hair and skin. The effects of elevated temperature on such substrates at the molecular level are, however, relatively unknown. This paper examines the response of peptides and proteins to hydrothermal damage using mass spectrometry and reports the location of molecular markers of hydrothermal damage within wool proteins.
The hydrothermal exposure of model peptides containing the oxidatively sensitive residues tryptophan and tyrosine revealed the formation of a number of products such as hydroxytryptophan and dihydrophenylalanine. A variety of degradation products were also observed in intermediate filament proteins, including products arising from deamidation and from oxidation of histidine, tyrosine and tryptophan residues.
The products observed to form during hydrothermal exposure indicated the involvement of reactive oxygen species. Molecular markers were identified within a proteinaceous system to allow the evaluation of damage type or severity. These findings have important implications for the thermal processing of foods and textiles.
肽和蛋白质的损伤导致蛋白质食品和纺织品质量和价值的损失，以及头发和皮肤等生物组织的退化。然而，在分子水平上，高温对这些底物的影响相对未知。本文使用质谱法研究了肽和蛋白质对湿热损伤的反应，并报告了羊毛蛋白中湿热损伤的分子标志物的位置。
含有氧化敏感残基色氨酸和酪氨酸的模型肽的湿热暴露揭示了许多产物的形成，如羟色氨酸和二氢苯丙氨酸。在中间丝蛋白中还观察到了多种降解产物，包括脱酰胺产物和组氨酸、酪氨酸和色氨酸残基氧化产物。
在湿热暴露过程中观察到的产物表明活性氧物质的参与。在蛋白质体系中鉴定了分子标志物，以允许评估损伤类型或严重程度。这些发现对食品和纺织品的热加工具有重要意义。
