Study of human pepsinogen polymorphism by combining chromatographic and electrophoretic methods.

A new combination of chromatographic and electrophoretic methods has been developed for better separation and characterization of human pepsinogens. Pepsinogens isolated from the gastric mucosa of patients with gastric cancer have been separated using fast-protein liquid chromatography (FPLC) on an ionex Uno-Q1 column. Proteolytic active fractions were firstly immunodetected by monoclonal antibodies against PGA and PGC using ELISA and then separated by isoelectric focusation in the acidic pH 2.

Immobilized-metal-ion affinity chromatography as a tool for the qualitative study of pepsinogen phosphorylation.

Affinity chromatography on immobilized Fe(3+) ions--immobilized-metal-ion affinity chromatography (IMAC) method--was used for the determination of pepsin and pepsinogen phosphorylation. IMAC is a very powerful method for detailed studies of proteins. Dephosphorylation of the pepsinogens and pepsins has no effect on their proteolytic ability.

Polyclonal antibodies for immunochemical determination of human pepsinogens.

The human gastric mucosa contains two main groups of aspartic proteinases, pepsin (EC 3.4.23.

[Role of protein phosphorylation in the development of tumors].

Phosphorylation is one of the most important ways of posttranslational modification of proteins that enables regulation of many cell physiological processes (transport, proliferation, differentiation). This reversible and very fast process is involved in all phases of cell division: in transition from G1 to S phase, progression of cells during S phase and entry into M phase. The physiological function of oncoproteins and tumor suppressor proteins that are involved in gene expression and replication are also regulated by phosphorylation.

Electrotitration curves of human gastric pepsinogens in agarose gels.

Electrotitration curves (ETC) of a marker protein mixture, pH 2.5-5.65, and human pepsinogens were performed in an agarose gel, containing 2% acid carrier ampholytes, forming a pH range of 2.