Compartmentation of free valine and its relation to protein turnover in perfused rat liver.

  title={Compartmentation of free valine and its relation to protein turnover in perfused rat liver.},
  author={Glenn E. Mortimore and K. H. Woodside and John E. Henry},
  journal={The Journal of biological chemistry},
  volume={247 9},

Figures and Tables from this paper

Valine uptake and incorporation into protein in isolated rat hepatocytes. Nature of the precursor pool for protein synthesis.

It is suggested that both the intracellular and the extracellular valine pools can directly provide precursors for protein synthesis, the relative contribution from each pool being proportional to the relative valine concentration in that pool, as suggested by Khairallah and co-workers.

Inhibition of the lysosomal pathway of protein degradation in isolated rat hepatocytes by ammonia, methylamine, chloroquine and leupeptin.

Protein degradation in isolated rat hepatocytes was measured as the release of [14C]valine from pre-labelled protein, consistent with the view that the majority of short-lived proteins are degraded by the non-lysosomal pathway(s).

Subcellular distribution of proteolytically generated valine in isolated rat hepatocytes.

It can be concluded that the non-extracted valine in hepatocytes may represent a steady-state level, maintained by intracellular protein degradation, of amino acid in transit through the cell, compatible with a limitation of valine efflux by the concentration-dependent valine transport system.

Rates of protein synthesis by hepatocytes isolated from rats of various ages

The rate of total protein synthesis in isolated hepatocytes was determined and is comparable to rates reported for perfused liver and liver in vivo and is approximately 64% higher than the rate of protein synthesis by hepatocytes from 18‐month‐old rats.


The incorporation into brain slice protein of externally provided [1‐14C]valine was measured under conditions of constant protein synthesis and equilibration of intracellular valine specific activity, indicating that the valine pool used for protein synthesis is not identical to the pool of total free valine.

Incorporation Rate of Leucine into Proteins in Human Liver Slices

Assuming that the rate of incorporation of leucine into hepatic proteins is representative of protein synthesis, the half‐life of liver proteins can be calculated to be 35 days for subjects below 60 years of age and for those who were older than 60 years, the protein turnover rate was approximately 30% higher.


Mature 193 , 821 chim

  • Biophys . Acta
  • 1962