Fraction of intracellular buffering capacity that is contributed by the side-chains and free amino- and carboxy-termini of amino acids and proteins

Range <1 %
Organism Budding yeast Saccharomyces cerevisiae
Reference Theillet FX et al., Physicochemical properties of cells and their effects on intrinsically disordered proteins (IDPs). Chem Rev. 2014 Jul 9 114(13):6661-714. doi: 10.1021/cr400695p p.6665 left column 2nd paragraphPubMed ID24901537
Primary Source [93] Roos A, Boron WF. Intracellular pH. Physiol Rev. 1981 Apr61(2):296-434 DOI: 10.1152/physrev.1981.61.2.296 [94] Poznanski J, Szczesny P, Ruszczyńska K, Zielenkiewicz P, Paczek L. Proteins contribute insignificantly to the intrinsic buffering capacity of yeast cytoplasm. iochem Biophys Res Commun. 2013 Jan 11 430(2):741-4. doi: 10.1016/j.bbrc.2012.11.079PubMed ID7012859, 23206695
Method Primary source [94] abstract: "Using data from both high-throughput experiments and in vitro laboratory experiments, [investigators] tested this concept [that a large portion of and possibly most of the cell's intrinsic (i.e., passive non-bicarbonate) buffering effect was attributed to proteins]. [They] assessed the buffering capacity of the yeast proteome using protein abundance data and compared it to [their] own titration of yeast cytoplasm."
Comments P.6665 left column 2nd paragraph: "As a rule of thumb, the pH of the cytoplasm is 7.2 (ref 91), and it is critical to maintain this value for any given organism (ref 92). Phosphate or bicarbonate ions and other weak acids and bases within the cell provide the intracellular buffering capacity, to which the side-chains and free amino- and carboxy-termini of amino acids and proteins contribute less than 1% (primary sources)."
Entered by Uri M
ID 115841