" ~" r" ELSEVIER Journal of Chromatography B, 688 (1997) 213-220 JOURNALOF CHROMATOGRAPHY B Fast detection of phosphorylation of human pepsinogen A, human pepsinogen C and swine pepsinogen using a combination of reversed-phase high-performance liquid chromatography and capillary zone electrophoresis for peptide mapping Radovan Hynek"'*, Vficlav Kagi~kab,Zdenka Kurerovfi c, Jan K~g a aDepartment of Biochemistry and Microbiology, Institute of Chemical Technology, Technichi 5 166 28 Prague 6, Czech Republic hlnstitute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nfm. 2 166 10 Prague 6, Czech Republic ~Department of Pathological Physiology, 1st Faculty of Medicine, Charles University, U nemocnice 5 128 53 Prague 2, Czech Republic Received 15 April 1996; revised 11 June 1996; accepted 24 June 1996 Abstract A combination of reversed-phase high-performance liquid chromatography (RP-HPLC) and capillary zone electrophoresis (CZE) was used for characterization of a-chymotryptic digests of human pepsinogen A, human pepsinogen C (both isolated from stomach mucosa of patients suffering from gastric cancer), swine pepsinogen and their dephosphorylated forms. Combining RP-HPLC and CZE for peptide mapping allowed to detect phosphorylations in molecules of the above mentioned gastric zymogens. We have found one phosphate group in the molecule of human pepsinogen A and two phosphate groups in the molecule of human pepsinogen C. The investigated sample was obtained from stomach mucosa of a patient suffering from gastric cancer. An increased number of phosphate groups in molecules of human pepsinogen seems to be associated with gastric cancer. The developed method represent a suitable tool for studying relationships between specific phosphorylations of proteins and cancerogenesis or potentially could serve for early diagnosis of gastric cancer. Keywords: Peptide mapping; Phosphorylation COMPOUND INDEX: Pepsinogens 1. Introduction Pepsinogens are produced in stomach mucosa cells Corresponding author as prepepsinogens with an N-terminal signal se- quence [1], which serves for transport across the endoplasmatic reticulum. Pepsinogen consists of a single polypeptide chain with an average relative molecular mass of 42 000. Its catalytic site contains 0378-4347/97/$17.00 Copyright © 1997 Elsevier Science B.V. All rights reserved PII S0378-4347(96)00293-9