Conversion of pepsinogen to pepsin at acid pH involves an intramolecular reaction in which the unproteolyzed zymogen cleaves itself. This conclusion is based upon experiments in which pepsinogen, at low concentrations, was activated in the presence of substrate, hemoglobin. Under these conditions, the activation of pepsinogen is independent of pepsinogen concentration, and addition of pepsin do...

Intramolecular pepsinogen activation is inhibited either by pepstatin, a potent pepsin inhibitor, or by purified globin from hemoglobin, a good pepsin substrate. Also, pepsinogen at pH 2 can be bound to a pepstatin-Sepharose column and recovered as native zymogen upon elution in pH 8 buffer. Kinetic studies of the globin inhibition of pepsinogen activation show that globin binds to a pepsinogen...

BACKGROUND Different acid and peptic related gastroduodenal diseases are associated with both increased gastric secretion and Helicobacter pylori infection. Patients with H pylori associated gastritis or duodenal ulcer have increased serum pepsinogen levels which decrease after eradication. The mechanisms of H pylori induced gastric mucosal damage are not completely understood. AIM To determi...

normal 0 false false false en-us x-none ar-sa background: gastric carcinoma is the second most common cause of cancer-related death in iran. it is well-known that atrophic gastritis is a major risk factor for gastric cancer, which leads to variations in the serum levels of gastrin 17 (g-17), pepsinogen i (p-i), and pepsinogen ii (p-ii). the aim of this study was to investigate the diagnostic ac...

1. Prochymosin in solution in the presence of 8 M-urea is fully unfolded, as indicated by its fluorescence spectrum, fluorescence quenching behaviour and far-u.v.c.d. spectrum. 2. Equilibrium studies on the unfolding of prochymosin and pepsinogen by urea were carried out at pH 7.5 and pH 9.0. The results indicate that the stabilization energies of the two proteins are identical at pH 7.5, but t...

1. A method is described for the preparation of pepsinogen from swine gastric mucosae which consists of extraction and fractional precipitation with ammonium sulfate solutions followed by two precipitations with a copper hydroxide reagent under particular conditions. Crystallization as very thin needles takes place at 10 degrees C., pH 5.0 and from 0.4 saturated ammonium sulfate solution contai...

Determination of the serum pepsinogen level is simple and the method gives consistent results. The serum pepsinogen level remains steady when the stomach is actively secreting pepsin. Age and sex do not greatly affect the serum pepsinogen concentration. Serum pepsinogen levels can be correlated with the histological appearances of the gastric mucosa. The parietal cells appear to be more sensiti...

OBJECTIVES In order to test the hypothesis that H. pylori infections in the gastric antrum increase pepsinogen I release, fasting serum pepsinogen I concentrations were compared in peptic ulcer patients with and without H. pylori infection. A randomized prospective study was performed to determine whether the increased serum pepsinogen I concentrations associated with H. pylori infection respon...

Intramolecular pepsinogen activation is inhibited either by pepstatin, a potent pepsin inhibitor, or by purified globin from hemoglobin, a good pepsin substrate. Also, pepsinogen at pH 2 can be bound to a pepstatin-Sepharose column and recovered as native zymogen upon elution in pH 8 buffer. Kinetic studies of the globin inhibition of pepsinogen activation show that globin binds to a pepsinogen...

Background Gastric cancer is the fifth most common malignancy in the world with almost one million new cases annually. Helicobacter pylori infection causes 89% of all gastric cancers. Premalignant lesions (atrophy and intestinal metaplasia) develop after several decades of inflammation. Secondary prevention with gastroscopy is possible, but it is costly and has a low compliance rate. Alternativ...