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

A combination of reversed-phase high-performance liquid chromatography (RP-HPLC) and capillary zone electrophoresis (CZE) was used for chara cterization of alpha-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 fo rms. Combining RP-HPLC and CZE for peptide mapping allowed to detect p hosphorylations 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 suff ering from gastric cancer. An increased number of phosphate groups in molecules of human pepsinogen seems to be associated with gastric canc er. The developed method represent a suitable tool for studying relati onships between specific phosphorylations of proteins and cancerogenes is or potentially could serve for early diagnosis of gastric cancer.