The server provides option of identification and predicting binder in antigen sequence. The user can perform prediction and identification separately (selecting either prediction or identification) or together by (selecting the "Both" option).
Identification of experimental binders-
The data of HLA binders for mapping was obtained from MHCBN version 3.1. The databases have more than 20,000 MHC binding peptides.
Prediction of MHC binders
The prediction of MHC binders is achieved by implementing the quantitative matrices.he matrices for class I alleles are obtained from Propred1 server. These matrices are originally derived from BIMAS server and literature. The matrices for class II alleles are obtained from ProPred1 servers. These matrices are originally derived from the virtual matrices of Sturniolo et al., 1999.
Parameters for Prediction
Threshold is an important parameter for prediction
During prediction, user can choose a cutoff threshold, which is defined as the 'percentage of best scoring natural peptides'. For example, a threshold of 1% would predict peptides in any given protein sequence that belongs to the 1% best scoring natural peptides. The threshold parameter allows user to modulate the stringency level in prediction results. A lower threshold (1%) corresponds to a high stringency prediction, i.e. to a lower rate of false positives and to a higher rate of false negatives. In contrast, a higher threshold value (low stringency) corresponds to a higher rate of false positives and a lower rate of false negatives. Authors suggest that for first round of screening, threshold values higher than 3% are not desirable, since the rate of false positives can increase the size of the predicted repertoire to an amount unacceptable for later experimental testing.The value of threshold can vary from 1% to 10%.
All peptide achieving score more then cutoff score at selected threshold will be assigned binders.
DisplayThe server displays the results in two formats i) HTML Mapping ii)Tabular. These reults display formats will be described in result display section of help.
Users can limit the number of top peptides to be displayed in tabular display.