Citrate synthase

high-resolution terminology - matching measurements at high-resolution

Citrate synthase

Description

Condensation of oxaloacetate with acetyl-CoA yields citrate as an entry into the TCA cycle. CS is located in the mt-matrix. CS activity is frequently used as a functional marker of the amount of mitochondria (mitochondrial elementary marker, mtE) for normalization of respiratory flux.

Abbreviation: CS

Reference: MiPNet17.04 CitrateSynthase

Normalization of respiratory flux for CS as a mitochondrial marker

Communicated by Gnaiger Erich last update 2020-04-19

Respiration of living or permeabilized cells, tissue homogenate or permeabilized tissue, and isolated mitochondria can be normalized for CS activity. Then marker-specific oxygen flux, J_O2/CS [pmol∙s­^-1∙IU­^-1], is a quantitative measure of respiration that reflects mitochondrial quality, independent of mitochondrial density.

Several publications in peer-reviewed journals report respiration normalized for CS activity in units which do not make sense, e.g. [pmol∙s^-­1∙mL­^-1∙IU­^-1], such that those numerical results are pointless. Clarification is obtained by strict definitions of normalization of rates [1] and dimensional analysis, summarized in MiPNet 17.04 [2].

1. Gnaiger E, Aasander Frostner E, Abdul Karim N, Abdel-Rahman EA, Abumrad NA, Acuna-Castroviejo D, Adiele RC, et al (2019) Mitochondrial respiratory states and rates. MitoFit Preprint Arch doi:10.26124/mitofit:190001.v6. - »Bioblast link«
2. Eigentler A, Draxl A, Gnaiger E (2020) Laboratory protocol: Citrate synthase a mitochondrial marker enzyme. Mitochondr Physiol Network 17.04(04):1-12. - »Bioblast link«

MitoPedia topics: Enzyme