A Comparison of the Protein Expression Lists from Mass Spectrometry of Human Blood Fluids Using Peptide Sequences and BLAST

摘要

The proteins in blood were all first expressed as mRNAs from genes within cells. There is a database of human proteins that are known to be expressed as mRNA in human cells termed the Reference Sequence (RefSeq) NP database. Any proteins identified from human blood by the correlation of mass sprectra that fail to match human mRNA expression products may not be correct. We compared the proteins identified in human blood by mass spectrometry by ten different groups. We determined whether the peptides or proteins identified by the different groups mapped to the known human expression products of the RefSeq database. The groups have used different sample preparation methods including LC-PAGE [1] or LC/LC-MS/MS [2-5], iso-electric focusing [6], no sample preparation followed by ultra HPLC [4], with fractionation followed by ultra HPLC [7], after low molecular mass filtration [8].