Complex I is bypassed during high intensity exercise.
Nat Commun
; 10(1): 5072, 2019 11 07.
Article
in En
| MEDLINE
| ID: mdl-31699973
ABSTRACT
Human muscles are tailored towards ATP synthesis. When exercising at high work rates muscles convert glucose to lactate, which is less nutrient efficient than respiration. There is hence a trade-off between endurance and power. Metabolic models have been developed to study how limited catalytic capacity of enzymes affects ATP synthesis. Here we integrate an enzyme-constrained metabolic model with proteomics data from muscle fibers. We find that ATP synthesis is constrained by several enzymes. A metabolic bypass of mitochondrial complex I is found to increase the ATP synthesis rate per gram of protein compared to full respiration. To test if this metabolic mode occurs in vivo, we conduct a high resolved incremental exercise tests for five subjects. Their gas exchange at different work rates is accurately reproduced by a whole-body metabolic model incorporating complex I bypass. The study therefore shows how proteome allocation influences metabolism during high intensity exercise.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Exercise
/
Adenosine Triphosphate
/
Muscle, Skeletal
/
Muscle Fibers, Skeletal
/
Electron Transport Complex I
/
Mitochondria, Muscle
Limits:
Adult
/
Humans
/
Male
Language:
En
Journal:
Nat Commun
Journal subject:
BIOLOGIA
/
CIENCIA
Year:
2019
Document type:
Article
Affiliation country:
Sweden