Label-free quantification is a valuable tool for the analysis of differentially expressed proteins identified by mass spectrometry methods.Herein,we used a new strategy:data-dependent acquisition mode identification combined with label-free quantification by SWATH acquisition mode,to study the differentially expressed proteins in mouse liver cancer metastasis cells.A total of 1528 protein groups were identified,among which 1159 protein groups were quantified and 249 protein groups were observed as differentially expressed proteins(86 proteins up-regulated and 163 down-regulated).This method provides a commendable solution for the identification and quantification of differentially expressed proteins in biological samples.
YAN ZiQiZHOU YuanSHAN YiChuWU QiZHANG ShenLIANG ZhenZHANG LiHuaZHANG YuKui
The human serum proteome is closely associated with the state of the body.Endogenous peptides derived from proteolytic enzymes cleaving on serum proteins are widely studied due to their potential application in disease-specific marker discovery.However,the reproducibility of peptidome analysis of endogenous peptides is significantly influenced by the proteolytic enzymes within body fluids,thereby limiting the clinical use of the endogenous peptides.We comprehensively investigated the N and C terminus of endogenous peptides using peptidomics.The cleavage site patterns of the N and C terminus and adjacent sites from all the identified endogenous peptides were highly conserved under different sample preparation conditions,including long-term incubation at 37℃ and pretreatment with repeated freeze-thaw cycles.Furthermore,a distinguishable cleavage site pattern was obtained when a different disease serum was analyzed.The conserved cleavage site pattern derived from proteolytic enzymes holds potential in highly specific disease diagnosis.
Fangjun WangJun ZhuLianghai HuHongqiang QinMingliang YeHanfa Zou
