State Key Laboratory of Meat Quality Control and Cultured Meat Development, Ministry of Education China, Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, China.
J Agric Food Chem. 2023 Oct 18;71(41):15287-15295. doi: 10.1021/acs.jafc.3c04208. Epub 2023 Oct 3.
The filamin C (FLNC) was hypothesized to be colocalized with its certain binding partners in pork tissues and calpain as well as caspase was assumed responsible for the postmortem degradation of FLNC. Therefore, the specific distribution of pork FLNC and its degradation pattern during postmortem aging were investigated in this study. The longissimus thoracis muscles from 12 pigs were removed from the carcasses and then aged at 4 °C for 1, 6, 12, 24, 72, and 168 h, respectively. The FLNC signals appeared to localize in subsarcolemmal areas by cross-sectional images, while the localization was found surrounding the myofibrils at the level of the Z-discs in longitudinal sections. FLNC displayed a highly overlapped spatial colocalization with actin or integrin. Western blot results showed that the intact 290 kDa FLNC was rapidly degraded to produce an approximately 280 kDa band. An almost overlapped distribution pattern was observed between FLNC and μ-calpain or caspase-3 in porcine skeletal muscle cells. Moreover, both the μ-calpain inhibitor and the caspase-3 inhibitor could inhibit the degradation of FLNC in porcine LT muscles during postmortem aging.
细丝蛋白 C（FLNC）假定与猪肉组织中的某些结合伴侣（如钙蛋白酶和半胱天冬酶）共定位，并且钙蛋白酶和半胱天冬酶负责 FLNC 的死后降解。因此，本研究旨在研究猪肉 FLNC 的特定分布及其在死后老化过程中的降解模式。从 12 头猪的胴体中取出背最长肌，然后在 4°C 下分别老化 1、6、12、24、72 和 168 小时。横断面图像显示 FLNC 信号似乎定位于横小管区域，而在纵断面水平上则发现定位于 Z 盘周围的肌原纤维周围。FLNC 与肌动蛋白或整合素表现出高度重叠的空间共定位。Western blot 结果表明，完整的 290 kDa FLNC 迅速降解为产生约 280 kDa 的条带。在猪骨骼肌细胞中，FLNC 与 μ-钙蛋白酶或半胱天冬酶-3 之间存在几乎重叠的分布模式。此外，μ-钙蛋白酶抑制剂和半胱天冬酶-3 抑制剂均可抑制死后老化过程中猪 LT 肌肉中 FLNC 的降解。
