An exploration of the methods to determine the protein-specific synthesis and breakdown rates in vivo in humans
Research output: Contribution to journal › Journal article › Research › peer-review
Standard
An exploration of the methods to determine the protein-specific synthesis and breakdown rates in vivo in humans. / Holm, Lars; Dideriksen, Kasper; Nielsen, Rie H.; Doessing, Simon; Bechshoeft, Rasmus L.; Højfeldt, Grith; Moberg, Marcus; Blomstrand, Eva; Reitelseder, Soren; van Hall, Gerrit.
In: Physiological Reports, Vol. 7, No. 17, e14143, 2019.Research output: Contribution to journal › Journal article › Research › peer-review
Harvard
APA
Vancouver
Author
Bibtex
}
RIS
TY - JOUR
T1 - An exploration of the methods to determine the protein-specific synthesis and breakdown rates in vivo in humans
AU - Holm, Lars
AU - Dideriksen, Kasper
AU - Nielsen, Rie H.
AU - Doessing, Simon
AU - Bechshoeft, Rasmus L.
AU - Højfeldt, Grith
AU - Moberg, Marcus
AU - Blomstrand, Eva
AU - Reitelseder, Soren
AU - van Hall, Gerrit
PY - 2019
Y1 - 2019
N2 - The present study explores the methods to determine human in vivo protein-specific myofibrillar and collagenous connective tissue protein fractional synthesis and breakdown rates. We found that in human myofibrillar proteins, the protein-bound tracer disappearance method to determine the protein fractional breakdown rate (FBR) (via (H2O)-H-2 ingestion, endogenous labeling of H-2-alanine that is incorporated into proteins, and FBR quantified by its disappearance from these proteins) has a comparable intrasubject reproducibility (range: 0.09-53.5%) as the established direct-essential amino acid, here L-ring-C-13(6)-phenylalanine, incorporation method to determine the muscle protein fractional synthesis rate (FSR) (range: 2.8-56.2%). Further, the determination of the protein breakdown in a protein structure with complex post-translational processing and maturation, exemplified by human tendon tissue, was not achieved in this experimentation, but more investigation is encouraged to reveal the possibility. Finally, we found that muscle protein FBR measured with an essential amino acid tracer prelabeling is inappropriate presumably because of significant and prolonged intracellular recycling, which also may become a significant limitation for determination of the myofibrillar FSR when repeated infusion trials are completed in the same participants.
AB - The present study explores the methods to determine human in vivo protein-specific myofibrillar and collagenous connective tissue protein fractional synthesis and breakdown rates. We found that in human myofibrillar proteins, the protein-bound tracer disappearance method to determine the protein fractional breakdown rate (FBR) (via (H2O)-H-2 ingestion, endogenous labeling of H-2-alanine that is incorporated into proteins, and FBR quantified by its disappearance from these proteins) has a comparable intrasubject reproducibility (range: 0.09-53.5%) as the established direct-essential amino acid, here L-ring-C-13(6)-phenylalanine, incorporation method to determine the muscle protein fractional synthesis rate (FSR) (range: 2.8-56.2%). Further, the determination of the protein breakdown in a protein structure with complex post-translational processing and maturation, exemplified by human tendon tissue, was not achieved in this experimentation, but more investigation is encouraged to reveal the possibility. Finally, we found that muscle protein FBR measured with an essential amino acid tracer prelabeling is inappropriate presumably because of significant and prolonged intracellular recycling, which also may become a significant limitation for determination of the myofibrillar FSR when repeated infusion trials are completed in the same participants.
KW - Amino acid recycling
KW - deuterated alanine
KW - deuterated water
KW - fractional breakdown rate
KW - fractional synthesis rate
KW - protein turnover
KW - stable isotope
U2 - 10.14814/phy2.14143
DO - 10.14814/phy2.14143
M3 - Journal article
C2 - 31496135
VL - 7
JO - Physiological Reports
JF - Physiological Reports
SN - 2051-817X
IS - 17
M1 - e14143
ER -
ID: 228370087