Targeted energy metabolomics analysis of postmortem pork in an in vitro model as influenced by protein
Wenwei Lu1, Qin Hou1, Jian Zhang1
1Key Laboratory of Meat Processing and Quality Control, 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.
Abstract:
For exploring the effect of protein S-nitrosylation on the energy metabolism of early postmortem pork (within 24 h postmortem), the six Longissimus thoracis (LT) muscle homogenates were treated with nitric oxide donor (NOR-3, (±)-(E)-4-Ethyl-2-(E)-hydroxyimino-5-nitro-3-hexenamide), nitric oxide synthase (NOS) inhibitor (L-NAME, Nω-nitro-L-arginine methyl ester hydrochloride) and control (0.1 M K2HPO4, pH 7.4) in the in vitro buffer system for 24 h, respectively. The western blotting result showed that NOR-3 treatment led to a greater level of protein S-nitrosylation (p < 0.05). However, S-nitrosylation levels had no significant difference between L-NAME and control groups (p > 0.05). In addition, results showed that 16 significantly differential energy metabolites were identified by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and clearly separated among three groups in the principal component analysis. Four pathways (glycolysis, tricarboxylic acid cycle, purine metabolism and pentose phosphate pathway) related to energy metabolism were significantly influenced by different levels of protein S-nitrosylation. Furthermore, the correlation analysis of metabolites demonstrated that metabolites were in dynamic equilibrium with each other. These results indicate that protein S-nitrosylation can participate in and regulate energy metabolism postmortem pork through glycolysis and tricarboxylic acid (TCA) cycle.
