The results were used to calculate the rate of change of the intracellular-specific activity of [.sup.14]C-glycine in the free amino acid pool
The change with time in specific activity of [.sup.14.C]-alanine in the intracellular free amino acid pool
was used to convert measurements of [.sup.14.C]-alanine in protein to rates of total alanine incorporation into protein.
Changes in the free amino acid pool
during environmental stress in the gill tissue of the oyster.
Histidine methylation during actin and myosin breakdown is the only source of 3-methylhistidine (3-MH), which is liberated into the plasma amino acid pool
. Several studies indicate that 3-MH is a valid index of muscle protein breakdown in rats (Young et al., 1972), rabbits (Nishizawa et al., 1977), cattle (Nishizawa et al., 1979), goats (Nishizawa et al., 1989) and humans (Long et al., 1975), because it is irreversibly excreted mainly into the urine (Young et al., 1978; Harris et al., 1981; Kocen et al., 1982; Nishizawa et al., 1984).
The rhizome amino acid pool
in both treatments was dominated by arginine, a nonprotein amino acid identified as [Delta]-acetylornithine (Lipson et al.
Our modifications included trace labeling over a short time interval ([less than] 18 min) to minimize possible effects of perturbations, caused by high transport rates of exogenous 14C-labeled amino acid, of the free amino acid pool
. A short exposure also avoided the interconversion of 14C-glycine, the tracer used in our measurements, into other amino acids (confirmed by analysis with high-performance liquid chromatgraphy, HPLC).
Do species with different degrees of mycorrhizal infection have differential access to the soil amino acid pool
? If some species can absorb amino acids in addition to ammonium and nitrate at higher rates than other species, what bearing does this have on interspecific competition for nitrogen?