An important interface modification for capillary isoelectric focusing mass spectrometry(CIEF MS) is reported. A capillary needle with a sheath flow tube pre mounted in one device serves as both the CIEF cathodic end ...An important interface modification for capillary isoelectric focusing mass spectrometry(CIEF MS) is reported. A capillary needle with a sheath flow tube pre mounted in one device serves as both the CIEF cathodic end and the ESI interface. The needle was inserted into the cathode reservoir at the focusing stage, and then removed to the front of sampler orifice of MS at the detection stage. Therefore, the shut off of the high voltage is not necessary and a better focusing protein zone is maintained during the ESI stage. The optimization of the experimental condition has been investigated and the two dimensional image of the E. coli proteins has been obtained, which is comparable with that from a 2D gel.展开更多
A novel approach of sequence pattern correlation has been applied to predict an expected amino acid sequence from CID ESI MS spectra. The proposed approach deduces sequence patterns with no help from known protein da...A novel approach of sequence pattern correlation has been applied to predict an expected amino acid sequence from CID ESI MS spectra. The proposed approach deduces sequence patterns with no help from known protein database such that it is useful to identify an unknown peptide or new protein. The algorithm applies a cross correlation to match an experimental CID spectrum with predicted sequence pattern generated from fragmentation information. The fragmentation knowledge of both y series and other non y series are utilized to generate the predicted sequence patterns. In contrast to the normal de novo approach, the proposed approach is insensitive to mass tolerance and non susceptive to spectral integrality with no need for selection of a starting point.展开更多
文摘An important interface modification for capillary isoelectric focusing mass spectrometry(CIEF MS) is reported. A capillary needle with a sheath flow tube pre mounted in one device serves as both the CIEF cathodic end and the ESI interface. The needle was inserted into the cathode reservoir at the focusing stage, and then removed to the front of sampler orifice of MS at the detection stage. Therefore, the shut off of the high voltage is not necessary and a better focusing protein zone is maintained during the ESI stage. The optimization of the experimental condition has been investigated and the two dimensional image of the E. coli proteins has been obtained, which is comparable with that from a 2D gel.
文摘A novel approach of sequence pattern correlation has been applied to predict an expected amino acid sequence from CID ESI MS spectra. The proposed approach deduces sequence patterns with no help from known protein database such that it is useful to identify an unknown peptide or new protein. The algorithm applies a cross correlation to match an experimental CID spectrum with predicted sequence pattern generated from fragmentation information. The fragmentation knowledge of both y series and other non y series are utilized to generate the predicted sequence patterns. In contrast to the normal de novo approach, the proposed approach is insensitive to mass tolerance and non susceptive to spectral integrality with no need for selection of a starting point.