ABSTRACT
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°C 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.
Subject(s)
Humans , Carcinoma, Hepatocellular , Blood , Diagnosis , Chromatography, High Pressure Liquid , Chromatography, Reverse-Phase , Liver Neoplasms , Blood , Diagnosis , Mass Spectrometry , Nanotechnology , Peptide Hydrolases , Metabolism , Peptides , Blood , Protein Structure, Tertiary , Proteome , Proteomics , Silicon Dioxide , Chemistry , Time FactorsABSTRACT
A novel mode of chiral separation in electrochromatography (CEC) with dynamically modified stationary phase (DMS-CEC) was presented. The capillary column was packed with strong anionic exchange stationary phase, the sulfated β-cyclodextrin (S-CD), which was added in the mobile phase, dynamically adsorbed to the packing surface and a new layer of chiral stationary phase was formed. The separation of enantiomer was based on their different interaction with the new stationary phase. The enantionmers of tryptophan, atropine and verapamil were successfully separated in this system with resolution of 2.06, 10.1 and 1.96, and the column effeciency for the enantiomers were varied from 85000 plates/m to 412000 plates/m. The relative standard deviation (RSD) of void time and the tryptophan enantiomers′ migration time for 17 consecutive runs were 0.5%, 0.6% and 0.7%, respectively. Enantiomer separation by capillary electrochromatography with adsorbed bovine serum albumin (BSA) and sulfated cyclodextrin (S-CD) as chiral stationary phases were also studied. The resolution for tryptophan enantiomers in the two systems were 3.86 and 2.97, respectively. It was found that the superiority of DMS-CEC over the adsorbed S-CD column CEC was that better repeatability could be obtained in DMS-CEC.
ABSTRACT
Reactive continuous rods of macroporous poly(glycidyl methacrylate-co-ethylene dimethacrylate) have been prepared by “in-situ” copolymerization of the monomers in the presence of porogenic dilute,and protein A was immobilized on the continuous rods directly or through a 11 carbon atom space arm with molded synthetic methods.The properties of these two rods columns were characterized and the results showed that the medium with space arm had some extent hydrophobicity.The affinity column without space arm was used to determine the human immunoglobulin G (HIgG) in human serum.The correlative coefficient of the calibration curve was 0.999.The effect of the flow rate on the pressure of the continuous rods was also investigated.The subclasses of HIgG were separated by the use of a pH gradient.