A comparative study of heat shock protein 70 in normal and PSE (pale, soft, exudative)-like muscle from broiler chickens.

This study investigated the level and location of heat shock protein 70 (HSP70) in pale, soft, and exudative (PSE)-like and normal chicken breast muscle (Pectoralis major [PM]) so as to identify HSP70 interacting proteins by immunoprecipitation. We found that HSP70 level in the PSE-like meat group was significantly lower than in the normal group (P < 0.05). Immuno-fluorescence indicated that HSP70 was present in the cytoplasm and on surface membranes of PM muscle fibers in the normal muscle group, while HSP70 was present on surface membranes and extracellular matrix, but was barely visible in the sarcoplasm of the PSE-like muscle group. According to HSP70-associated protein analysis, most of the proteins were glycolytic pathway enzymes, structural proteins, and molecular chaperones. The HSP70-interacted protein of heat shock protein 90 and 6-phosphofructokinase were clearly different between the two groups. Our research suggested that HSP70 may be associated with an unknown mechanism that leads to such variation in meat quality; the abundance and activity of HSP70 binding proteins may play a significant role in this process.