Enrichment of Phosphorylated Peptides with Metal-Organic Framework Nanosheets for Serum Profiling of Diabetes and Phosphoproteomics Analysis
Yang, SS (Yang, Shi-Shu)[ 1 ] ; Chang, YJ (Chang, Yu-Jie)[ 1 ] ; Zhang, H (Zhang, Hao)[ 2 ] ; Yu, XZ (Yu, Xizhong)[ 2 ] ; Shang, WB (Shang, Wenbin)[ 2 ] ; Chen, GQ (Chen, Gui-Quan)[ 3 ] ; Chen, DDY (Chen, David Da Yong)[ 1,4 ]*; Gu, ZY (Gu, Zhi-Yuan)[ 1 ]*（古志远）
[ 1 ] Nanjing Normal Univ, Jiangsu Key Lab Biofunct Mat, Jiangsu Collaborat Innovat Ctr Biomed Funct Mat, Coll Chem & Mat Sci, Nanjing 210023, Jiangsu, Peoples R China
[ 2 ] Nanjing Univ Chinese Med, Coll Clin Med 1, Key Lab Metab Dis Chinese Med, Nanjing 210023, Jiangsu, Peoples R China
[ 3 ] Nanjing Univ, State Key Lab Pharmaceut Biotechnol, MOE Key Lab Model Anim Dis Study, Model Anim Res Ctr, 12 Xuefu Ave, Nanjing 210061, Jiangsu, Peoples R China
[ 4 ] Univ British Columbia, Dept Chem, Vancouver, BC V6T 1Z1, Canada
ANALYTICAL CHEMISTRY, 201811,90(22), 13796-13805
Capturing phosphopeptides from complicated biological samples is essential for the discovery of new post translational modification sites and disease diagnostics. Although several two-dimensional (2-D) materials have been used for phosphopeptides capturing, metal-organic framework (MOF) nanosheets have not been reported. The Ti-based MOF nanosheets have well-defined 2-D morphology, high density of active sites, large surface area, and an ultrathin structure. Phosphopeptides can be efficiently extracted and superior detection limits of 0.1 fmol mu L-1 can be achieved even for an extremely low molar ratio of phosphoprotein/nonphosphoprotein (1:10000) mixtures. The selectivity over nonphosphopeptides can be enhanced further by pretreatment with a 10 mM salt solution (beta-glycerophosphate disodium, NaCI, or KC1). The performance of 2-D Ti-based MOF nanosheets is much better than Zr-based MOF (Zr-BTB) nanosheets or any other Ti-based 3-D MOF counterpart, such as MIL-125 and NH2-MIL-125. The nanosheets were used for in situ isotope labeling for abnormally regulated phosphopeptides analysis from serum samples of type 2 diabetes patients. The relative quantitative results showed that three of the phosphorylated fibrinogen peptides A (FPA, DpSGEGDFLAEGGGV, DpSGEGDFLAEGGGVR, and ADpSGEGDFLAEGGGVR) were down-regulated, while the other isoform (ADpSGEGDFLAEGGGV) was up-regulated in the serum samples of type 2 diabetes patients compared with those of healthy volunteers. Finally, proteomics analysis showed selective enrichment of phosphopeptides with 2-D Ti-based MOF nanosheets from real samples, including tryptic digests of mouse brain neocortex lysate, mouse spinal cord lysate, and mouse testis lysate, followed by LC-MS/MS analysis. Total numbers of 2601, 3208, and 2866 phosphopeptides were successfully identified from the three samples, respectively. The 2-D Ti-based MOF nanosheets significantly improved sample preparation for mass spectrometric analysis in phosphopeptides and phosphoproteomics research.