Antigenic predicts potentially antigenic regions of a protein sequence, using the method of Kolaskar and Tongaonkar. This method is based on a single parameter and thus very simple to use.
Analysis of data from experimentally determined antigenic sites on proteins has revealed that the hydrophobic residues Cys, Leu and Val, if they occur on the surface of a protein, are more likely to be a part of antigenic sites. The method of Kolaskar and Tongaonkar to predict antigenic determinants in proteins is semi-empirical and makes use of physicochemical properties of amino acid residues and their frequencies of occurrence in experimentally known segmental epitopes.
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Here is the default Eantigenic.dat file:
# Antigenic Surface Antigenic # Amino -- Occurrence of amino acids in -- frequency frequency propensity # Acid Epitopes Surface Protein f(Ag) f(s) A(p) A 135 328 524 0.065 0.061 1.064 C 53 97 186 0.026 0.018 1.412 D 118 352 414 0.057 0.066 0.866 E 132 401 499 0.064 0.075 0.851 F 76 180 365 0.037 0.034 1.091 G 116 343 487 0.056 0.064 0.874 H 59 138 191 0.029 0.026 1.105 I 86 193 437 0.042 0.036 1.152 K 158 439 523 0.076 0.082 0.930 L 149 308 684 0.072 0.058 1.250 M 23 72 152 0.011 0.013 0.826 N 94 313 407 0.045 0.058 0.776 P 135 328 411 0.065 0.061 1.064 Q 99 252 332 0.048 0.047 1.015 R 106 314 394 0.051 0.058 0.873 S 168 429 553 0.081 0.080 1.012 T 141 401 522 0.068 0.075 0.909 V 128 239 515 0.062 0.045 1.383 W 19 55 103 0.009 0.010 0.893 Y 71 158 245 0.034 0.029 1.161 Total 2066 5340 7944
Application of this method to a large number of proteins has shown that their method can predict antigenic determinants with about 75% accuracy which is better than most of the known methods.
Original program "ANTIGENIC" by Peter Rice (EGCG 1991)