Table 1

Omission mixture analysis of synthetic mimicry epitope

PM1#11 stimulating peptideSequenceOmitted in X1 μM, cpm
Human GAD65 339–352 TVYGAFDPLLAVAD
Library 1 epitope SIAMAFDPOIPMAA
Library 2 epitope TDSLAFEPKVPRRQ
Omission mixture TDSXAFEPKVPRRQ L, I, M, V, A, G, Y, F, C 8,395  ± 1,536
TDSLXFEPKVPRRQ A, C 2,885  ± 1,227
TDSLAXEPKVPRRQ F, C 28  ± 12
TDSLAFXPZVPRRQ D, N, E, Q, S, T, A, V, G, C 166,815  ± 13,517
TDSLAFEXKVPRRQ P, C 40  ± 12
TDSLAFBPXVPRRQ K, R, H, P, C 144,517  ± 7,736
TDSLAFEPKXPRRQ L, I, M, V, A, G, C 151  ± 97
TDSLAFEPKVXRRQ P, A, C 1,223  ± 632
  • The sequences of GAD65 339–352, the library 1 epitope, and the library 2 epitope are aligned. Relative positions 1–8 of the three peptides are highly similar (underlined). An omission mixture analysis of relative positions 1–8 of the library 2 epitope is described. Peptide mixtures based on the library 2 epitope were tested for stimulation of PM1#11 in a T cell proliferation assay at total concentrations of 1 μM (mean of triplicate, ± SD). In each mixture all natural l-amino acids were present at position X (underlined), except the amino acids omitted. At position Z (underlined) all natural l-amino acids, except C and D were present. Background counts were 127 ± 40 cpm (mean ± SD of triplicate). The positive control response against GAD65 339–352 was 166,587 ± 10,336 (mean ± SD of triplicate).