2 -3 sec/residue
||Yewdell JW, Reits E, Neefjes J. Making sense of mass destruction: quantitating MHC class I antigen presentation. Nat Rev Immunol. 2003 Dec3(12):952-61. DOI: 10.1038/nri1250 p.955 left column top paragraphPubMed ID14647477
|| Reits, E. et al. Peptide diffusion, protection, and degradation in nuclear and cytoplasmic compartments before antigen presentation by MHC class I. Immunity 18, 97–108 (2003).PubMed ID12530979
||Primary source abstract: "[Investigators] have visualized the fate and dynamics of intracellular peptides in living cells."
||P.955 left column top paragraph: "Peptidases are largely excluded from the nucleus [primary source], implying that trimming of nuclear peptides occurs only after the peptide diffuses to the cytoplasm, which is also the exclusive site of TAP [transporter for antigen processing, primary source]. On the basis of kinetic data, more than 99% of intracellular peptides are destroyed before encountering TAP: in living cells, cytosolic aminopeptidases remove one residue every 2–3 seconds [primary source]. The endopeptidase thimet oligopeptidase (TOP) seems to have a particularly important role in destroying potential antigenic peptides that are generated by proteasomes [ref 37]."