Quantitative LC-MS/MS Proteomics of human small intestine

The objective was to determine the expression of a wide range proteins pertinent to metabolism and disposition of chemicals and nutrients in the intestinal epithelium. Ileum and jejunum biopsy specimens were obtained from 16 patients undergoing gastrointestinal elective surgery. Mucosal fractions were prepared and analysed using targeted and global proteomic approaches. A total of 29 enzymes, 32 transporters, 6 tight junction proteins, 2 adhesion proteins, alkaline phosphatase, thioredoxin, 5 markers and 1 regulatory protein were quantified; 60 for the first time.