High-throughput quantification with label-free methods has received considerable attention in electrospray ionization(ESI)-mass spectrometry(MS),but the manner by which MS signals respond to peptide concentration remains unclear in proteomics.We developed a new mathematical formula to describe the intrinsic log-log relationship between the MS intensity response and peptide concentration in an analytical ESI process.Experimental results showed that the calibration curve is fairly fit to the log-log formula with a linear dynamic range of approximate four to five orders of magnitude.However,we found that the ionization of analytical peptides can be severely suppressed by coexisting matrix peptides,such that the calibration curve can be poorly leveled off on both ends.Our study suggests that the interferences from coexisting matrix peptides should be reduced in the ESI process to use the log-log calibration curve successfully for the high-throughput quantification.
LU WenYuanYIN XueFeiLIU XiaoHuiYAN GuoQuanYANG PengYuan
Proteomics focuses on the systematic identification and quantification of entire proteomes and interpretation of proteins’biological functions.During the last decade,proteomics in China has grown much faster than other research fields in life sciences.At the beginning of the second decade of the 21st century,the rapid development of high-resolution and high-speed mass spectrometry makes proteomics a powerful tool to study the mechanisms underlying physiological/pathological processes in organisms.This article provides a brief overview of proteomics technology development and representative scientific progress of the Human Liver Proteome Project in China over the past three years.
LI NingXU Zhong WeiZHAI Lin HuiLI Yan ChangFAN Feng XuZHENG Jun JieXU PingHE Fu Chu
Recently, we have analyzed expressional transcriptome and proteome for a number of cancer cell lines, including 8 hepatocellular carcinoma （HCC） ones [1,2]. These 8 HCC cell lines consist of 6 metastatic （all with mutant p53） and 2 non-metastatic （with a mutant and a lost p53） ones, being all HBV traceable for relatively close genetic-backgrounds. We have analyzed the related dataset and obtained transcrip- tome （16353 genes） and proteome （7861 proteins） of these 8 HCC cell lines, and explored a group of up-regulated and down-regulated genes [3].
