Metabolism of myofibrillar proteins in the normal and hypertrophic heart
The pathways of myofibrillar assembly and degradation were studied in normal heart and during developing hypertrophy by two independent methods: amino acid incorporation kinetics and the double isotope technique.
The validity and sensitivity of both methods were evaluated by computer analysis of data for which leucyl-tRNA was used as a protein precursor.
The data obtained indicate that the myofibrillar proteins turn over at nonuniform rates. The half-lives of the proteins studied increase as follows: myosin HC = α-actin = tropomyosin > LC1 = LC2 > actin. In the case of light chains, a macromolecular precursor pool was detected which contributes to the observed lower labeling with 3H-leucine.
During developing hypertrophy, the rate of light-chain labeling is increased relative to that of heavy chains.
Stoffwechsel der myofibrillären Proteine in normalen und hypertrophierten Herzen
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