Identification and characterization of a metalloprotease activity from Helicobacter pylori.
نویسندگان
چکیده
Helicobacter pylori produces a metalloprotease with a native molecular size of approximately 200 kDa, as determined by size-exclusion chromatography. Subcellular distribution studies demonstrated that the activity was associated with the outer membrane fraction of the bacterium. In addition, the protease was secreted by the bacterium when grown in liquid culture. The enzyme activity was measured by hydrolysis of azocasein and biotinylated casein and exhibited optimal caseinolytic activity at pH 8.0 (37 degrees C). The activity was inhibited by EDTA, 1,10-phenanthroline, phosphoramidon, pyridine-2,6-dicarboxylic acid, and 8-hydroxyquinoline-5-sulfonic acid (HQSA). Inhibition by HQSA was reversed by zinc, whereas inhibition due to EDTA was reversed by excess calcium, thus indicating that the enzyme was a zinc-dependent, calcium-stabilized endoproteinase. Furthermore, titration with Zn2+ of a desalted, active-site zinc-chelated preparation of the protease demonstrated that Zn2+ was essential for activity. Leupeptin, phenylmethylsulfonyl fluoride, E-64, pepstatin A, dithiothreitol, and 2-mercaptoethanol had no effect on enzymatic activity. Addition of Ca2+ or Mg2+ to the incubation medium resulted in approximately a twofold stimulation of the azocaseinolytic activity of the enzyme. The protease was stably expressed since it was active even after repeated subculture of the bacterium. Bovine serum albumin, hide powder azure, and elastin-Congo red remained intact even after prolonged exposure to the enzyme. The surface expression of this metalloprotease activity raises the possibility that this enzyme may be involved in the proteolysis of a variety of host proteins in vivo and thereby contributes to gastric pathology.
منابع مشابه
PCR and RFLP Analysis for Identification and Typing of Helicobacter pylori Strains from Gastric Biopsy Specimens
متن کامل
Purification and Characterization of 50 kDa Extracellular Metalloprotease from Serratia sp. ZF03
Background: Proteolytic enzymes have an important role in variety of physiological and pathological functions. They have been used in therapeutic and pharmaceutical applications. Characterizations of extracellular proteases from various strains of S. marcescens indicate that most strains produce a very similar major metalloprotease. This metalloprotease (serrapeptidase, serrapeptase) is an impo...
متن کاملPurification and Characterization of a Thermostable Neutrophilic Metalloprotease from Pseudomonas sp. DR89
A novel neutrophilic metalloprotease was isolated from Pseudomonas sp. DR89 isolate which was identified ina mineral spring in Iran. The enzyme was purified from the isolate to 21-folds in a three-step procedure involving ammonium sulfate precipitation, Q-Sepharose ionic exchange and Sephadex G-100 gel filtrationchromatography. Resuts showed that the enzyme was active at high temper...
متن کاملSimultaneous Detection of Helicobacter Genus and Helicobacter pylori Species using a Multiplex PCR Method
In order to improve simultaneous detection and identification of Helicobacter genus in general and Helicobacter pylori specifically and reduce the number of amplifications needed, we established a multiplex PCR. In this study, two pairs of primers: Hcom1 and Hcom2 specific for Helicobacter genus, Hicd1 and Hicd2 specific for Helicobacter pylori species were used. To determine the sensitivity of...
متن کاملCompression of Histopathology, Culture and Rapid Urease Test in Diagnosis of Helicobacter Pylori in Gastric Biopsy Specimens
Abstract Background and Objective: Helicobacter pylori (H. Pylori) infection is related to chronic gastritis, peptic ulcer, duodenal ulcer and gastric cancer. Thus, identification and treatment of the infection have a considerable importance. The aim of this study was to compare three methods of Histopathology, Culture and Rapid Urease test (RUT) in identification of H. Pylori in gastric bio...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Infection and immunity
دوره 65 8 شماره
صفحات -
تاریخ انتشار 1997