scholarly journals The isolation and properties of a non-pepsin proteinase from human gastric mucosa

1978 ◽  
Vol 169 (3) ◽  
pp. 617-624 ◽  
Author(s):  
N B Roberts ◽  
W H Taylor
Keyword(s):  
Bone Marrow ◽  
Gastric Mucosa ◽  
Gastric Adenocarcinoma ◽  
Proteolytic Activity ◽  
Structural Characteristics ◽  
Human Gastric Mucosa ◽  
Cathepsin E ◽  
Activity Curve ◽  
Rabbit Bone ◽  
Ph Range

1. A non-pepsin proteinase, proteinase 2, was successfully isolated free from pepsinogen (by repetitive chromatography on DEAE- and CM-celluloses) from the gastric mucosa of a patient with a duodenal ulcer and the uninvaded mucosa of a patient with a gastric adenocarcinoma. 2. Proteinases 1a and 1b, found in gastric adenocarcinoma, were not found in the gastic mucosa of these patients. 3. Proteinase 2 was shown to have an asymmetrical broad pH-activity curve with a maximum over the pH range 3.0-3.7. 4. Proteolytic activity of proteinase 2 was inhibited by pepstatin; the concentration of pepstatin giving 50% inhibition is of the order of 3nm. 5. Inhibition of proteolytic activity by carbenoxolone and related triterpenoids indicated that at pH 4.0 proteinase 2 possesses structural characteristics relating it to the pepsins and at pH 7.4 to the pepsinogens. 6. The sites of cleavage of the B-chain of oxidized insulin for proteinase 2 at pH 1.7 and pH 3.5 were shown to be similar to those previously established for human pepsin 3 and for the cathepsin E of rabbit bone marrow. 7. The non-pepsin proteinase 2 (cathepsin) of human gastric mucosa has properties more similar to cathepsin E than to the cathepsins D.

scholarly journals A neutral collagenase from human gastric mucosa

1976 ◽  
Vol 153 (1) ◽  
pp. 119-126 ◽  
Author(s):  
D E Woolley ◽  
J S Tucker ◽  
G Green ◽  
J M Evanson
Keyword(s):  
Gastric Mucosa ◽  
Serum Proteins ◽  
Gel Filtration ◽  
Molecular Size ◽  
Collagen Molecule ◽  
Human Gastric Mucosa ◽  
Reaction Products ◽  
Specific Viscosity ◽  
Collagen Molecules ◽  
Ph Range

Biopsy specimens of human gastric mucosa, maintained in culture for 7 days in the absence of serum, released a collagen-degrading enzyme into the medium. The yield of active enzyme reached a maximum after 2-3 days, and viable tissue, capable of protein synthesis, was essential for its production. 2. At 25 degrees C the enzyme attacked undenatured collagen in solution, resulting in a 55% loss of specific viscosity and producing the two products TCA and TCB characteristic of neutral-collagenase action. 3. Electron microscopy of segment-long-spacing crystallites of these reaction products showed the exact cleavage locus of the collagen molecules to be between bands 43 and 44 (I-43). The larger TCA and smaller TCB products were fragments representing 77 and 23% respectively of the length of the collagen molecule. 4. Optimal enzyme activity was observed over the pH range 7.5-8.5 and a mol.wt. of approx. 38000 was derived from gel-filtration studies. 5. The enzyme was shown to be inhibited by the human serum proteins ²2-macroglobulin and a smaller component of mol.wt. approx. 40000; α1-anti-trypsin was not inhibitory. 6. EDTA, 1, 10-phenanthroline, cysteine and dithiothreitol all inhibited collagenase activity. 7. The gastric enzyme has properties similar to other well characterized collagenases, but differences exist with respect to its molecular size and the site of attack on the collagen molecule.

scholarly journals Identification of the aspartic proteinases from human erythrocyte membranes and gastric mucosa (slow-moving proteinase) as catalytically equivalent to cathepsin E

1988 ◽  
Vol 254 (3) ◽  
pp. 895-898 ◽  
Author(s):  
R A Jupp ◽  
A D Richards ◽  
J Kay ◽  
B M Dunn ◽  
J B Wyckoff ◽  
...  
Keyword(s):  
Gastric Mucosa ◽  
Human Erythrocyte ◽  
Ph Value ◽  
Polyacrylamide Gel Electrophoresis ◽  
Erythrocyte Membranes ◽  
Human Gastric Mucosa ◽  
Aspartic Proteinases ◽  
Cathepsin E ◽  
Activity Measurements ◽  
Human Erythrocyte Membranes

Three aspartic proteinases with similar Mr values (approx. 80,000) but from distinct sources (human gastric mucosa, human erythrocyte membranes and rat spleen) were shown to have immunological cross-reactivity and comparable mobilities when subjected to polyacrylamide-gel electrophoresis under non-denaturing conditions. Kinetic parameters (kcat, Km and Ki) were determined for the interactions of the three enzymes with two synthetic chromogenic substrates and five inhibitors (naturally occurring and synthetic). On this basis it would appear that all of the enzymes should be considered equivalent to cathepsin E. pH-activity measurements indicated that the aspartic proteinase that originated from the erythrocyte membranes retained activity at a higher pH value than either of its readily soluble counterparts.

The structure of pre-mRNA and mRNA from erythroid cells

1978 ◽  
Vol 36 (2) ◽  
pp. 234-235
Author(s):  
A.-M. Ladhoff ◽  
B.J. Thiele ◽  
Ch. Coutelle ◽  
S. Rosenthal
Keyword(s):  
Bone Marrow ◽  
Structural Transformation ◽  
Electron Micrographs ◽  
Ammonium Acetate ◽  
Bone Marrow Cells ◽  
Erythroid Cells ◽  
Globin Mrna ◽  
Ordered Structures ◽  
Rabbit Bone ◽  
Rabbit Reticulocytes

The suggested precursor-product relationship between the nuclear pre-mRNA and the cytoplasmic mRNA has created increased interest also in the structure of these RNA species. Previously we have been published electron micrographs of individual pre-mRNA molecules from erythroid cells. An intersting observation was the appearance of a contour, probably corresponding to higher ordered structures, on one end of 10 % of the pre-mRNA molecules from erythroid rabbit bone marrow cells (Fig. 1A). A virtual similar contour was observed in molecules of 9S globin mRNA from rabbit reticulocytes (Fig. 1B). A structural transformation in a linear contour occurs if the RNA is heated for 10 min to 90°C in the presence of 80 % formamide. This structural transformation is reversible when the denatured RNA is precipitated and redissolved in 0.2 M ammonium acetate.

Sem Observations in Gastric Mucosa Exposed to Progressive Enzymatic Etching

1980 ◽  
Vol 38 ◽  
pp. 570-571
Author(s):  
C.A.E. Lemmi ◽  
D. Booth ◽  
G.E. Adomian
Keyword(s):  
Gastric Mucosa ◽  
Critical Point ◽  
Proteolytic Activity ◽  
Etching Process ◽  
Cellular Types

In order to enrich populations of homogeneous cellular types we dissociated gastric mucosa by enzymatic techniques. In addition, we used SEM to monitor the progressive etching of the mucosa. Two enzymes were tested: collagenase III with minimum proteolytic activity and Pronase with broader proteolytic effects. The gastric mucosa was exposed to the effect of the enzymes using everted stomach preparations. In this way the digestive action occured progressively from the lumen of the stomach toward the base of the glands. This “etching” process could be monitored conveniently by SEM. After incubation for periods varying from 30 to 210 minutes the tissues were stretched on dental wax, fixed in 2 % glutaralheyde, post-fixed in osmium, dehydrated, critical point dryed and coated with gold. A model MSM-5 “Mini-SEM” was used for observation. Gentle uncurling of the preparation before coating with gold produced fractures which revealed the structure of the gastric glandsin more detail.

H. pylori down-regulates TRAIL (DR4)-receptors in the human gastric mucosa, a possible mechanism for chronic persistence

2001 ◽  
Vol 120 (5) ◽  
pp. A81-A81
Author(s):  
B NEU ◽  
R RAD ◽  
M NEUHOFER ◽  
C TRAUTWEIN ◽  
M GERHARD ◽  
...  
Keyword(s):  
Gastric Mucosa ◽  
Human Gastric Mucosa ◽  
H Pylori
Sign in / Sign up

Export Citation Format

Share Document