Proteomic analysis of slow- and fast-twitch skeletal muscles.
Skeletal muscles are composed of slow- and fast-twitch muscle fibers, which have high potential in aerobic and anaerobic ATP production, respectively. To investigate the molecular basis of the difference in their functions, we examined protein profiles of skeletal muscles using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and two-dimensional gel electrophoresis with pH 4-7 and 6-11 isoelectric focusing gels. A comparison between rat soleus and extensol digitorum longus (EDL) muscles that are predominantly slow- and fast-twitch fibers, respectively, showed that the EDL muscle had higher levels of glycogen phosphorylase, most glycolytic enzymes, glycerol 3-phosphate dehydrogenase, and creatine kinase; while the soleus muscle had higher levels of myoglobin, TCA cycle enzymes, electron transfer flavoprotein, and carbonic anhydrase III. The two muscles also expressed different isoforms of contractile proteins including myosin heavy and light chains. These protein patterns were further compared with those of red and white gastrochnemius as well as red and white quadriceps muscles. It was found that metabolic enzymes showed a concerted regulation dependent on muscle fiber types. On the other hand, expression of contractile proteins seemed to be independent of the metabolic characteristics of muscle fibers. These results suggest that metabolic enzymes and contractile proteins show different expression patterns in skeletal muscles.
Division of Protein Metabolism, Institute for Protein Research, Osaka University, Osaka, Japan. nokumura@protein.osaka-u.ac.jp
Nobuaki
N
Okumura
Akiko
A
Hashida-Okumura
Kanako
K
Kita
Masami
M
Matsubae
Toshiya
T
Matsubara
Toshifumi
T
Takao
Katsuya
K
Nagai
D000818:Animals; D015180:Electrophoresis, Gel, Two-Dimensional; D009119:Muscle Contraction; D018656:Muscle Fibers, Fast-Twitch / Q000737:chemistry / Q000378:metabolism*; D018657:Muscle Fibers, Slow-Twitch / Q000737:chemistry / Q000378:metabolism*; D009124:Muscle Proteins / Q000302:isolation & purification / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000737:chemistry / Q000294:innervation / Q000378:metabolism*; D010449:Peptide Mapping; D040901:Proteomics; D051381:Rats; D017208:Rats, Wistar; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D009124:Muscle Proteins