20 min to 60 hours
||Doherty MK, Hammond DE, Clague MJ, Gaskell SJ, Beynon RJ. Turnover of the human proteome: determination of protein intracellular stability by dynamic SILAC. J Proteome Res. 2009 Jan8(1):104-12. doi: 10.1021/pr800641v. p.108 left column 2nd paragraphPubMed ID18954100
|| Dice JF, Goldberg AL. Relationship between in vivo degradative rates and isoelectric points of proteins. Proc Natl Acad Sci U S A. 1975 Oct72(10):3893-7.  Dice, J. Fred Hess, Emma Jean Goldberg, Alfred L. Studies on the relation between the degradative rates of proteins in vivo and their isoelectric points. Biochemical Journal (1979), 178 (2), 305-12 CODEN: BIJOAK ISSN:0306-3275. link PubMed ID1060070, 36075
||Primary source  abstract:"A double-isotope method was used to compare degradative rates of soluble proteins separated by isoelectric focusing."
||P.108 left column 2nd paragraph:"Dice and Goldberg performed an analogous study to the molecular weight correlation experiment and found a general trend: acidic proteins are less stable than neutral or basic proteins (primary sources), although once again, in their analysis, there were notable exceptions. For example, proteins with an isoelectric point of ∼6 ranged in half-life from 20 min to 60 h. One of the primary restrictions of such analyses is that they focus on averaged “total protein” data and do not look at the degradation rates of individual proteins." Primary source  studied rat & mouse, primary source  studied rat, mouse & human