An impact of l-histidine on the phosphorylation and stability of pyruvate kinase at low NaCl level

•Exogenous l-his was applied at the early postmortem muscle.•l-hist caused a PK dephosphorylation at 1% NaCl level.•The activity and stability of PK were significantly affected by l-his.•Providing a new breakthrough for low-NaCl meat products quality improvement. As one of the key rate limiting enzymes in glycolysis process, the characteristics of pyruvate kinase (PK) play an important role in regulating the muscle quality. Given the close relationship between kinase phosphorylation level and its stability, the present study investigated the impact of exogenous l-histidine (l-his) on PK phosphorylation and activity at 1% NaCl level in the early postmortem. An incubation system was also constructed and the results showed that the introduction of 0.06% l-his caused the dephosphorylation and increased the activity of PK at 1% NaCl. Compared with 1% NaCl treatment, three differential phosphorylation sites were produced when l-his was introduced. The PK secondary structure was shift from order to disorder, leading to a distinct degradation. This present study provided us with inspiration that meat quality could be improved by exogenous l-his at early postmortem under low NaCl conditions.