Host response profile of human brain proteome in toxoplasma encephalitis

Frontal cortex brain tissues obtained from 5 toxoplasma encephalitis patients and 5 controls were used for protein extraction. Protein amount was normalized on 10% SDS-PAGE, equal amount of protein from 5 patients and 5 controls were pooled separately and subjected to reduction, alkylation and trypsin digestion. iTRAQ labelling of samples were carried out in replicates. Peptides from control samples were labelled with iTRAQ labels leading to the reporter ions of 114 and 115 whereas peptides from patient samples were labelled with iTRAQ labels leading to the reporter ions of 116 and 117. Labelled peptides were then pooled and subjected to SCX fractionation and obtained 21 fractions, which were subsequently subjected to high-resolution Fourier transform mass spectrometry (LTQ-Orbitrap Velos).