The peptides were extracted twice with 0.1% TFA in 50% acetonitrile. Extracts were pooled and lyophilized. The resulting lyophilized tryptic peptides were dissolved in 5 mg/ml CHCA containing 0.1% TFA and 50% acetonitrile. MALDI-TOF-TOFMS
analyses were conducted using 4800 Plus MALDI-TOF-TOFTM
analyzer (Applied Biosystems, Foster City,CA,USA).