Department of Animal Science, Iowa State University, Ames, Iowa 50011, United States.
Department of Animal Science, University of Connecticut, Storrs, Connecticut 06269, United States.
J Agric Food Chem. 2024 May 29;72(21):12229-12239. doi: 10.1021/acs.jafc.4c00335. Epub 2024 May 14.
The objective was to understand the impacts of secondary lipid oxidation products on calpain-2 activity and autolysis and, subsequently, to determine the quantity and localization of modification sites. 2-Hexenal and 4-hydroxynonenal incubation significantly decreased calpain-2 activity and slowed the progression of autolysis, while malondialdehyde had minimal impact on calpain-2 activity and autolysis. Specific modification sites were determined with LC-MS/MS, including distinct malondialdehyde modification sites on the calpain-2 catalytic and regulatory subunits. 2-Hexenal modification sites were observed on the calpain-2 catalytic subunit. Intact protein mass analysis with MALDI-MS revealed that a significant number of modifications on the calpain-2 catalytic and regulatory subunits are likely to exist. These observations confirm that specific lipid oxidation products modify calpain-2 and may affect the calpain-2 functionality. The results of these novel experiments have implications for healthy tissue metabolism, skeletal muscle growth, and post-mortem meat tenderness development.
目的是了解次级脂质氧化产物对钙蛋白酶-2 活性和自溶的影响，进而确定修饰部位的数量和位置。2-己烯醛和 4-羟基壬烯醛孵育显著降低钙蛋白酶-2 活性并减缓自溶的进展，而丙二醛对钙蛋白酶-2 活性和自溶的影响最小。通过 LC-MS/MS 确定了特定的修饰部位，包括钙蛋白酶-2 催化亚基和调节亚基上明显的丙二醛修饰部位。在钙蛋白酶-2 催化亚基上观察到 2-己烯醛的修饰部位。用 MALDI-MS 进行完整蛋白质质量分析表明，钙蛋白酶-2 催化亚基和调节亚基上可能存在大量修饰。这些观察结果证实，特定的脂质氧化产物修饰钙蛋白酶-2 并可能影响钙蛋白酶-2 的功能。这些新实验的结果对健康组织代谢、骨骼肌生长和死后肉嫩度发展有影响。
