Proteome analysis of the sarcoplasmic fraction of pig semimembranosus muscle: implications on meat color development.
Two-dimensional electrophoresis was used to investigate sarcoplasmic protein expression in pig Semimembranosus muscles sampled 20 min after slaughter. Two groups (light and dark) of 12 animals were selected from 1000 pigs, based on meat L values measured 36 h postmortem. Twenty-two proteins or fragments (p < 0.05) were differentially expressed. Muscles leading to darker meat had a more oxidative metabolism, indicated by more abundant mitochondrial enzymes of the respiratory chain, hemoglobin, and chaperone or regulator proteins (HSP27, alphaB-crystallin, and glucose-regulated protein 58 kDa). Conversely, enzymes of glycolysis were overexpressed in the lighter group. Such samples were also characterized by higher levels of glutathione S-transferase omega, which can activate the RyR calcium channels, and higher levels of cyclophilin D. This protein pattern is likely to have severe implications on postmortem metabolism, namely, acceleration of ATP depletion and pH fall and subsequent enhanced protein denaturation, well-known to induce discoloration.
Sayd
Thierry
T
Qualité des Produits Animaux, INRA, 63122 St. Genès-Champanelle, France.
Morzel
Martine
M
Chambon
Christophe
C
Franck
Michel
M
Figwer
Philippe
P
Larzul
Catherine
C
Le Roy
Pascale
P
Monin
Gabriel
G
Chérel
Pierre
P
Laville
Elisabeth
E
D000818:Animals; D003116:Color; D005838:Genotype; D008460:Meat; D009124:Muscle Proteins / Q000032:analysis*; D020543:Proteome / Q000032:analysis*; D012519:Sarcoplasmic Reticulum / Q000737:chemistry*; D013552:Swine / Q000235:genetics
D009124:Muscle Proteins; D020543:Proteome