Table II Polarity and size of C-terminal residues among HLA-B27 subtype-bound peptides. The nature of residue 116 in each subtype is indicated. Figures are residue frequencies (%) among the peptides sequenced from the corresponding subtype. Values selectively increased in a subtype group are highlighted in boldface. For the statistical significance of the differences in residue usage among subtypes in the C-terminal position see supplemental Table S6
B*27:02 (D116)B*27:03 (D116)B*27:04 (D116)B*27:05 (D116)B*27:06 (Y116)B*27:07 (Y116)B*27:09 (H116)
POLARITY
    Basic2.121.94.517.41.61.83.1
    Non-polar Aliphatic35.237.150.241.678.767.974.0
    Non-polar Aromatic (F)29.817.222.421.915.427.019.3
    Polar Aromatic (Y)30.121.521.017.72.42.11.9
SIZE (Da)
    57–1032.57.010.46.913.99.69.6
    104–11530.326.337.430.463.752.158.6
    116–1374.617.26.614.24.28.49.3
    138–18662.649.645.648.418.330.022.5