Bombyx mori anterior silk gland LC-MS/MS

The anterior silk gland in the silkworm plays an important role in the process of liquid fibroin to solid silk fiber .In view of this,the proteomics analysis was applied to to study the relationship between the function of proteins in the anterior silk gland and the mechanism of spinning. The anterior silk glands on the 3rd day of fifth instar were dissected.Aftter 1D SDS-PAGE ,one gel lane was cut into 10 bands and each band further sliced into small pieces was subjected to in-gel tryptic digestion for 20 hours.The digested peptides were separated by RP nanoscale capillary liquid chromatography and analyzed using a surveyor LC system (Thermo Figgigan, San Jose, CA).The eluate from the RP column was analyzed by Finnigan LTQ(Thermo Electron Corporation）linear ion trap Mass equipped with a nanospray souce in the positive ion mode. The MS analysis was performed with one full MS scan followed by three MS/MS scans on the most intense ions from the MS spectrum with the dynamic exclusion settings: repeat count 2, repeat duration 30s, exclusion duration 90s. Data were acquired in data-dependent mode using Xcalibur software.Ten raw datasets from LC-MS/MS were searched against the predicted silkworm database by Xia.et al which consists of 21312 silkworm proteins.The searching was carried out with the Turbo SEQUEST(Bioworks version 3.2, Thermo Electron).