residues (amino acids)
||Juliane Liepe et al., A large fraction of HLA class I ligands are proteasome-generated spliced peptides, Science 21 October 2016 • Vol 354 Issue 6310 pp.354-359 p.355 middle column 2nd paragraph
|| A. F. Kisselev, T. N. Akopian, K. M. Woo, A. L. Goldberg, The sizes of peptides generated from protein by mammalian 26 and 20 S proteasomes. Implications for understanding the degradative mechanism and antigen presentation. J. Biol. Chem. 274, 3363–3371 (1999). doi:10.1074/jbc.274.6.3363  Mishto M et al, Driving forces of proteasome-catalyzed peptide splicing in yeast and humans. Mol Cell Proteomics. 2012 Oct11(10):1008-23. DOI: 10.1074/mcp.M112.020164PubMed ID9920878, 22822185
||P.354 middle column bottom paragraph: "To overcome these problems, [investigators] developed an analytical strategy that accounts for recent discoveries underpinning the PCPS (proteasome-catalyzed peptide splicing) mechanism and can handle the vast proteome-wide human spliced peptide database (fig. S3). With this strategy, [they] initially analyzed the HLA-I–eluted immunopeptidome of the GR lymphoblastoid cell line (GR-LCL) for a deeper coverage of the immunopeptidome, [they] adopted a two-dimensional (2D) peptide prefractionation strategy followed by a hybrid peptide fragmentation method [electron-transfer higher-energy collision dissociation (EThcD)] for peptide identification (refs 3, 4) (fig. S1), supplemented by an adapted target-decoy approach (fig. S4)." HLA= human leukocyte antigen
||P.355 middle column 2nd paragraph: "The numbers of both nonspliced and spliced 9- to 12-mer peptides declined when [investigators] used an inhibitor of proteasome activity such as epoxomicin (Fig. 1C and fig. S9). Inhibition of proteasome activity led to a longer median length of the nonspliced peptides (fig. S9), which was to be expected since proteasome generates peptides with an average length of 11 residues (primary sources). It also eliminated almost all spliced 9- to 12-mer peptides (Fig. 1C and fig. S9), thereby confirming that the identified spliced peptides are generated by proteasome."