Dl. Hasten et al., Isolation of human skeletal muscle myosin heavy chain and actin for measurement of fractional synthesis rates, AM J P-ENDO, 38(6), 1998, pp. E1092-E1099
Citations number
28
Categorie Soggetti
Endocrinology, Nutrition & Metabolism
Journal title
AMERICAN JOURNAL OF PHYSIOLOGY-ENDOCRINOLOGY AND METABOLISM
Using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE),
we have developed a simple method to isolate myosin heavy chain (MHC) and
actin from small (60-80 mg) human skeletal muscle samples for the determina
tion of their fractional synthesis rates. The amounts of MHC and actin isol
ated are adequate for the quantification of [C-13]leucine abundance by gas
chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS). Frac
tional synthesis rates of mixed muscle protein (MMP), MHC, and actin were d
etermined in six healthy young subjects (27 +/- 1 yr) after they received a
14-h intravenous infusion (prime = 7.58 mu mol/kg body wt, constant infusi
on = 7.58 mu mol.kg.body wt(-1).h(-1)) of [1-C-13]leucine. The fractional s
ynthesis rates of MMP, MHC, and actin were found to be 0.0468 +/- 0.0048, 0
.0376 +/- 0.0033, and 0.0754 +/- 0.0078%/h, respectively. Overall, the synt
hesis rate of MHC was 20% lower (P = 0.012), and the synthesis rate of acti
n was 61% higher (P = 0.060, not significant) than the MMP synthesis rate.
The isolation of these proteins for isotope abundance analysis by GC-C-IRMS
provides important information about the synthesis rates of these specific
contractile proteins, as opposed to the more general information provided
by the determination of MMP synthesis rates.