The objective of this study was to compare the effects of two oxidation systems on the biochemical properties of yak myofibrillar protein (MP). Oxidation was induced by incubating MP with either an iron-catalyzed oxidizing system (IOS) or a metmyoglobin-oxidizing system (MOS). The following indicators of protein oxidation and protein degradation were analyzed. The carbonyl, disulfide bonds, dityrosine, and β-sheet content increased markedly with oxidant concentration in both systems(P < .05), whereas the total sulfhydryl, surface hydrophobicity and α-helix content decreased significantly(P < .05). Furthermore, the MOS carbonyl formation rate was significantly faster than the IOS rate, and the MOS significantly affected the formation of disulfide bonds and inhibited the exposure of hydrophobic amino acids. Both oxidative systems promoted cross-linking of myosin heavy chains (MHCs) and action, but the degree of cross-linking in IOS was greater than that in MOS. MOS also promoted cross-linking of myosin light chains (MLCs). IOS and MOS produced mainly 20–25-kDa and 20–17-kDa MLC degradation products, respectively. In conclusion, oxidation caused cross-linking in MHCs or MLCs through disulfide bonds, but the extent of such cross-linking was oxidant dose-dependent and specific to each oxidizing system.

这项研究的目的是比较两种氧化系统对牛肌原纤维蛋白（MP）的生化特性的影响。通过将MP与铁催化氧化系统（IOS）或肌红蛋白氧化系统（MOS）孵育来诱导氧化。分析了以下蛋白质氧化和蛋白质降解的指标。在两个系统中，羰基，二硫键，二氢酪氨酸和β-折叠含量均随氧化剂浓度显着增加（P  <.05），而总巯基，表面疏水性和α-螺旋含量则显着降低（P <.05）。此外，MOS羰基形成速率明显快于IOS速率，并且MOS显着影响二硫键的形成并抑制疏水氨基酸的暴露。两种氧化系统都促进了肌球蛋白重链（MHCs）的交联和作用，但IOS中的交联程度大于MOS中的。MOS还促进了肌球蛋白轻链（MLC）的交联。IOS和MOS分别主要产生20–25-kDa和20–17-kDa的MLC降解产物。总之，氧化引起MHC或MLC中通过二硫键的交联，但是这种交联的程度取决于氧化剂的剂量，并且对每个氧化系统都是特定的。