| Use of 18O-labelled leucine and phenylalanine to measure protein turnover in muscle cell cultures and possible futile cycling during aminoacylation. | |
| | |
MedLine Citation:
|
PMID: 8373357 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
Amino acids labelled with 18(O) on both carboxy oxygen atoms have the potential for use as non-recyclable tracers to measure protein turnover. During protein synthesis one of the labelled oxygen atoms is removed, and thus release of the mono-labelled amino acid could be used to determine proteolysis. Primary cultures of embryonic-chick skeletal-muscle cells were used to test the use of 18(O2)-labelled Leu to measure proteolysis. For 9-day cultures, prelabelled on days 2-8 with medium containing one-half the Leu as [18O2]Leu and one-half as [2H3]Leu, release of [18(O)]Leu was less than 50% that of [2H]Leu over 24 h, suggesting a loss of the 18O label by a mechanism other than protein synthesis. Medium containing [18(O2)]Leu, [2H3]Leu, [18O2]Phe and [13C]Phe was then incubated with 9-day cultures to compare the rate of loss of the 18(O)-label from Leu and Phe with the rate of uptake of the non-carboxy-oxygen-labelled amino acids. Results for Leu demonstrated an 81% loss of the 18(O) label compared with a 33% decrease in [2H]Leu over 12 h. Loss of the 18(O) label was four times as great for Leu as for Phe. Loss of the 18(O) label was not decreased by addition of cycloheximide or by addition of a 3-fold excess of Ile, Val and Tyr; thus the loss of label was not due to protein synthesis alone or to misbinding to incorrect tRNAs. Infusion of the isotopes into pigs showed that the 18(O) label of Leu was not lost during transamination to alpha-ketoisocaproate (alpha-oxoisohexanoate). The most probable explanation is that the 18(O) label is lost as a result of the enzymic deacylation of tRNA, that this process is substantially faster for Leu than for Phe, and that this represents a potentially costly futile cycle for Leu. |
| | |
Authors:
|
J C Fuller; S L Nissen; T W Huiatt |
Related Documents
:
|
23107717 - Taurine-nitrite interaction as a precursor of alkylation mechanisms. 8678317 - Obelin mrna--a new tool for studies of translation in cell-free systems. 6793087 - Mechanisms of hormonal modulation of ion transport in the toad's urinary bladder. subce... 12729607 - General properties of gfp-display, an electrophoretic analysis for single amino acid ch... 12108217 - Quantitative and qualitative analysis of lipids in genetically modified potato tubers w... 3016007 - Seasonal variations in the stability of monoamines and their metabolites in perchloric ... |
Publication Detail:
|
Type: Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S. |
Journal Detail:
|
Title: The Biochemical journal Volume: 294 ( Pt 2) ISSN: 0264-6021 ISO Abbreviation: Biochem. J. Publication Date: 1993 Sep |
Date Detail:
|
Created Date: 1993-10-13 Completed Date: 1993-10-13 Revised Date: 2010-09-13 |
Medline Journal Info:
|
Nlm Unique ID: 2984726R Medline TA: Biochem J Country: ENGLAND |
Other Details:
|
Languages: eng Pagination: 427-33 Citation Subset: IM |
Affiliation:
|
Department of Animal Science, Iowa State University, Ames 50011. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Acylation Animals Cells, Cultured Chick Embryo Cycloheximide / pharmacology Deuterium Kinetics Leucine / metabolism* Muscle Proteins / metabolism* Muscles / embryology, metabolism* Oxygen Isotopes Phenylalanine / metabolism* Swine |
| Chemical | |
Reg. No./Substance:
|
0/Muscle Proteins; 0/Oxygen Isotopes; 61-90-5/Leucine; 63-91-2/Phenylalanine; 66-81-9/Cycloheximide; 7782-39-0/Deuterium |
| Comments/Corrections | |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Hydralazine induces Z-DNA conformation in a polynucleotide and elicits anti(Z-DNA) antibodies in tre...
Next Document: The C-terminal region of alpha-crystallin: involvement in protection against heat-induced denaturati...