Isolation of aminoacyl-tRNA and its labeling with stable-isotope tracers: Use in studies of human tissue protein synthesis

Journal Article · Mon Jul 01 04:00:00 EDT 1991 · Proceedings of the National Academy of Sciences of the United States of America; (United States)

DOI:https://doi.org/10.1073/pnas.88.13.5892· OSTI ID:6100246

Watt, P W; Lindsay, Y; Scrimgeour, C M; Chien, P A.F.; Taylor, D J; Rennie, M J ^[1]; Gibson, J N.A. ^[2]

---

1. Univ. of Dundee (England)
2. Univ. of Dundee (England) Univ. of Edinbergh (England)

The authors isolated aminoacyl-tRNA from human and rat tissues and measured, by GC/MS, its labeling in vivo by ({sup 15}N)-and ({sup 13}C)leucine. Tracer dilution artifacts seemed unlikely since, after infusion of L-(1-{sup 13}C, {sup 15}N)leucine into rats, (1) muscle leucyl-tRNA labeling exceeded tissue free leucine labeling, (2) values were largely unaffected by storing over 5 min at 22C, and (3) L-(2,4,5-methyl-{sup 13}C)leucine was not incorporated into leucyl-tRNA during homogenization. Leucyl-tRNA labeling in liver and muscle suggested charging from extra- and intracellular pools: e.g., after infusing L-(1-{sup 13}C, {sup 15}N)leucine, rat muscle tissue free leucine {sup 13}C labeling exceeded that by {sup 15}N and both were significantly lower than venous plasma indicating tracer dilution by transamination and by proteolysis; however, leucyl-tRNA labeling by either isotope was significantly above mixed tissue free leucing. Human placental leucyl-tRNA labeling (after predelivery tracer infusion) was 37% lower than maternal uterine vein labeling but not significantly different from placental free leucine or umbilical arterial leucine.

• OSTI ID: 6100246
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America; (United States), Journal Name: Proceedings of the National Academy of Sciences of the United States of America; (United States) Vol. 88:13; ISSN 0027-8424; ISSN PNASA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
BIOSYNTHESIS
CARBON 13
CARBON ISOTOPES
CARBOXYLIC ACIDS
DOUBLE LABELLING
EVEN-ODD NUCLEI
ISOTOPE APPLICATIONS
ISOTOPES
LABELLING
LEUCINE
LIGHT NUCLEI
MASS SPECTROSCOPY
MUSCLES
NITROGEN 15
NITROGEN ISOTOPES
NUCLEI
NUCLEIC ACIDS
ODD-EVEN NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
PATIENTS
PROTEINS
RNA
SPECTROSCOPY
STABLE ISOTOPES
SYNTHESIS
TRACER TECHNIQUES
TRANSFER RNA