title: Absolute quantitative profiling of the key metabolic pathways in slow and fast skeletal muscle.
abstract: Slow and fast skeletal muscles are composed of, respectively, mainly oxidative and glycolytic muscle fibers, which are the basic cellular motor units of the motility apparatus. They largely differ in excitability, contraction mechanism, and metabolism. Because of their pivotal role in body motion and homeostasis, the skeletal muscles have been extensively studied using biochemical and molecular biology approaches. Here we describe a simple analytical and computational approach to estimate titers of enzymes of basic metabolic pathways and proteins of the contractile machinery in the skeletal muscles. Proteomic analysis of mouse slow and fast muscles allowed estimation of the titers of enzymes involved in the carbohydrate, lipid, and energy metabolism. Notably, we observed that differences observed between the two muscle types occur simultaneously for all proteins involved in a specific process such as glycolysis, free fatty acid catabolism, Krebs cycle, or oxidative phosphorylation. These differences are in a good agreement with the well-established biochemical picture of the muscle types. We show a correlation between maximal activity and the enzyme titer, suggesting that change in enzyme concentration is a good proxy for its catalytic potential in vivo. As a consequence, proteomic profiling of enzyme titers can be used to monitor metabolic changes in cells. Additionally, quantitative data of structural proteins allowed studying muscle type specific cell architecture and its remodeling. The presented proteomic approach can be applied to study metabolism in any other tissue or cell line.
authors.affiliation: Department of Animal Molecular Physiology, Wroclaw University , Wroclaw 50-205, Poland.
authors.forename: Dariusz
authors.initials: D
authors.lastname: Rakus
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Gizak
authors.forename: Atul
authors.initials: A
authors.lastname: Deshmukh
authors.forename: Jacek R
authors.initials: JR
authors.lastname: Wiśniewski
mesh_terms: D000818:Animals; D002853:Chromatography, Liquid; D002952:Citric Acid Cycle; D005227:Fatty Acids / Q000378:metabolism; D005260:Female; D006019:Glycolysis; D051379:Mice; D008810:Mice, Inbred C57BL; D018656:Muscle Fibers, Fast-Twitch / Q000378:metabolism*; D018657:Muscle Fibers, Slow-Twitch / Q000378:metabolism*; D010085:Oxidative Phosphorylation; D011768:Pyruvate Dehydrogenase Complex / Q000378:metabolism; D053719:Tandem Mass Spectrometry
chemical_list: D005227:Fatty Acids; D011768:Pyruvate Dehydrogenase Complex
keywords: absolute protein quantitation; carbohydrate metabolism; energy metabolism; fatty acid metabolism; filter aided sample preparation; glycolysis; label free quantitative proteomics; “total protein approach”