Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.3 (collagenase)
 18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Extracts of highly purified lysosomes from rat liver were examined for their ability to degrade native collagen and thermally denatured collagen at pH values between 3.5 and 7.0. After a 24-h digestion at 36 degrees with the lysosomal extract at a pH of 5.5 or lower (collagen/lysosomal protein; 2/1 or 8/1), both native and denatured collagen were degraded to an extent equivalent to 60 to 70% of that observed upon total acid hydrolysis in 6 N HCl as measured by the ninhydrin reaction (570 nm). At a pH of 6.0, native collagen and denatured collagen were degraded by the mixture of lysosomal proteinases to 11% and 40% of total acid hydrolysis, respectively. At pH 6.5 AND 7.0, the corresponding values were 3% versus 33% and 0.3% versus 11%, respectively. Fragments of collagen (TCA and TCB) are produced when mammalian collagenase degrades native collagen at 25 degrees. These fragments were degraded by the lysosomal extract at 36 degrees to an extent equivalent to 28% and 8% of total acid hydrolysis at pH 6.5 and 7.0, respectively. The experiments at pH 6.5 and 7.0 were done using a collagen/lysosomal protein ratio of 2/1. At pH 5.0 (a pH which is found within secondary lysosomes), the lysosomal extracts degraded collagen to a mixture of free amino acids and small peptides. Amino acid analysis established that approximately 30% of the amino acid residues of the collagen appeared in the lysosomal hydrolysate as free amino acids. Hydroxyproline and perhaps hydroxylysine were the only amino acids found in collagen which did not appear at least to some extent as the free amino acid in this hydrolysate.
 ...
PMID:Digestion of native collagen, denatured collagen, and collagen fragments by extracts of rat liver lysosomes. 0 59

The binding of Ca2+ to a salivary phosphoprotein, protein C, was studied by equilibrium dialysis. In 5mM-Tris/HCl buffer, pH 7.5, protein C bound 190 nmol of Ca2+/mg of protein. The apparent dissociation constant, K, was determined to be 1.9 x 10(-4)M and the binding of Ca2+ to the protein was non-co-operative. The binding of Ca2+ to protein C apparently depends on groups which ionize above pH 5.0. Ca2+ binding decreased with increased concentration of the dialysis buffer and on addition of SrCL2, MgCl2 and MnCl2 to the dialysis buffer. Digestion of protein C with trypsin or collagenase or heating of the protein to 60 degrees or 100 degrees C had little or no effect on the Ca2+ binding. Digestion of protein C with alkaline phosphatase caused a decrease in the amount of protein-bound Ca2+. This was also found for another salivary phosphoprotein, protein A. In the absence of Ca2+ the S020,w for protein C was 1.29 S and in the presence of Ca2+ it was 1.46S. Ca2+ may cause a conformational change in the protein or an aggregation of the protein molecules. No conformational changes of protein C in the presence of Ca2+ could be detected by circular dichroism or nuclear magnetic resonance.
 ...
PMID:The binding of calcium to a salivary phosphoprotein, protein C, and comparison with calcium binding to protein A, a related salivary phosphoprotein. 1 96

By electron microscopic studies collagenase, hyaluronidase, HCl, ascorbic acid, and iron ions have been found to attack the collagen fibers of bovine vitreous. Because of the possible role of ascorbic acid in collagen synthesis and the ability of ascorbic acid to degrade hyaluronic acid and collagen we suggest that the ascorbic acid of the vitreous essentially participates in construction and metabolism of the vitreous body.
 ...
PMID:[Electron microscopic investigations of vitreous collagen after treating the vitreous with liquefying substances (author's transl)]. 16 9

Collagenase (EC 3.4.24.3) activity can be measured directly in homogenates of the involuting rat uterus. Latent forms of collagenase are activated by a brief exposure to trypsin; trypsin activity is then blocked with soybean trypsin inhibitor. Homogenizing conditions have been developed that permit 90-95% recovery of the total active and latent collagenase activity in a 6000 X g pellet, where it is presumably bound to its collagen substrate. This insoluble activity can then be extracted by heating to 60 degrees C for 4 min in 0.04 M Tris - HCl buffer, pH 7.5, containing 0.1 M CaCl2. Methods are presented for the estimation of the recovery of collagenase in the extracts; this approximates 65-70% of the total. Small amounts of activity can also be extracted from rat liver and kidney. This extraction procedure should be of use in purifying collagenase without culturing the enzyme-producing tissue and in the direct assay of tissue collagenase activity. The activity extracted from rat uterus has been proven to be collagenase by its characteristic pattern of collagen breakdown products on disc electrophoresis and by the split of tropocollagen at interband 41 as shown by electron microscopy of reconstituted fragments. The activity is inhibited by EDTA, and this inhibition is not reversed by calcium or zinc ions.
 ...
PMID:Extraction of collagenase from the involuting rat uterus. 18 74

The application of scanning electron microscopy to the study of cell surfaces is limited in intact tissues, because extracellular material may often obscure the details of nonluminal surfaces. To remove connective tissue elements we have treated human skin and both kidney, and an autonomic ganglion of the rat with hydrochloric acid and collagenase. Regional variations in the basal surface of the nephron are noted following removal of the basement membrane. The basilar interdigitations of the cells of the proximal tubule appeared as parallel ridges encircling the tubule. Ridges on the parietal epithelium of Bowman's capsule were randomly arranged and alternated with smooth surfaces. The dermal surface of the human epidermis has an alveolar or honeycomb appearance due to the elevation of the epidermal ridges and numerous pits for the dermal pegs. At higher magnifications the basal surface of cells of the stratum germinativum possessed numerous and irregular projections. Neurons with their processes are evident in the autonomic ganglion. The soma of the neurons are enclosed by flattened satellite cells. Irregular spaces between opposed satellite cells are interpreted as regions for the passage of processes related to the ganglion cells. Nodes of Ranvier were clearly seen along nerve fibers. Some pitting of the nerve fibers was also noted. The HCl-collagenase method has the advantage of the removal of collagen and basement membrane while preserving the structural integrity of the cell surface.
 ...
PMID:Scanning electron microscopy of cell surfaces following removal of extracellular material. 18 20

Collagenolytic activity has been demonstrated in the early phase of chemical carcinogenesis of mouse skin following 3-methylcholanthrene application dropwise in acetone or painted on the skin in benzene. In addition very high levels of collagenase could be detected in mouse skin papillomas and carcinomas. In all the tissues investigated, collagenase activity was extracted from the 6000 X g sediment of tissue homogenates with 5 M urea in 50 mM Tris-HCl buffer, pH 7.5. After dialyzing the extract, the enzyme was precipitated with ammonium sulfate and the activity determined against 14C-collagen substrate in solution. This procedure was found suitable for the detection and estimation of collagenase activity in skin tissues with high turnover of collagen and thus offers an attractive alternative to tissue culture methods.
 ...
PMID:Extractable collagenase and carcinogenesis of the mouse skin. 20 Mar 99

Elastin was extracted from human aortic plaque and adjacent grossly normal intima by the following methods: (1) 0.1 N NaOH at 100 degrees C, (2) hot NaOH and 0.2 M EDTA, (3) 5 M guanidine--HCl and collagenase, (4) guanidine--collagenase and dithioerythritol--urea--sodium dodecyl sulfate, (5) guanidine--collagenase and EDTA, (6) 10% NaCl and collagenase, and (7) NaCl--collagenase and EDTA. All elastin samples contained small amounts of carbohydrate and hydroxyproline. The lipid content of non-plaque intimal elastin samples was small (2--3%), whereas it increased to 4--6% in plaque intima. The lipid composition of elastin preparations varied significantly with the extraction procedure. Elastin from plaque intima contained significantly more cholesterol (50--60%) and less triglyceride and phospholipid than elastin of non-plaque intima (30--50% cholesterol). The contents of free and esterified cholesterol were comparable in all preparations. The main phospholipid in all samples was sphingomyelin, which comprised between 50 and 80% of the total phospholipid. Compared with NaOH-purified elastin, the other elastin samples were characterized by an increased phosphatidyl--choline content, while they all contained an almost equal amount of phosphatidylethanolamine. In elastin samples from plaque intima, the polar amino acids were increased, whereas cross-linking amino acids were decreased. The polarity and hydroxyproline content of elastin samples were slightly decreased after treatment with EDTA or dithioerythritol--urea--sodium dodecyl sulfate.
 ...
PMID:Elastin--lipid interaction action in the arterial wall. Part 1. Extraction of elastin from human aortic intima. 46 28

Retinal capillaries of the rabbit were treated with HCl and collagenase to visualize the pericytes attached to the stromal surface of the capillary walls under the scanning electron microscope. Two types of pericytes were distinguishable on the basis of shape and localization. One type (Type I) had a slightly bulged, fusiform cell body with a few, long, branching cytoplasmic processes, and these cells were scattered mainly in the region of the true capillary. The other type (Type II) possessed a rather flattened and polymorphic cell body from which radiated short irregular cytoplasmic processes, and these cells, which tended to overlap more or less, were present predominantly in the region of the pre- or postcapillary vessels in the capillary bed. The latter type cells were assumed to be precursors of the smooth muscle cells.
 ...
PMID:Surface view of pericytes on the retinal capillary in rabbits revealed by scanning electron microscopy. 53 85

When attempts at teasing adult Dipetalonema streptocerca free from biopsy specimens of human skin proved futile a digestion procedure was initiated. Punch biopsy specimens fixed in Michel's solution (ammonium sulfate) were incubated at 25 degrees C for 3 days in a 1.0% solution of collagenase in tris-HCl buffer. Intact worms were carefully teased out of the digested collagen and camera lucida drawings and measurements were then possible. This marks the first description of intact D. streptocerca adults recovered from man.
 ...
PMID:Recovery of intact male and female Dipetalonema streptocerca from man. 57 Dec 13

The innervation of the salivary gland of the cockroach Nauphoeta cinerea (Olivier) has been investigated with the use of light and scanning electron microscopy. Light microscopy of methylene blue stained glands reveals the presence of a dual innervation arising from the ventral nerve cord and the stomodeal nervous system; the principal innervation is that from the ventral nerve cord which passes to the gland via the reservoir ducts. Branches of these nerves form a plexus on the acinar surface, the axons of which exhibit swelling at irregular intervals. The presence of this surface plexus and the axonal swellings was confirmed by scanning electron microscopy both in normal glands and in those in which the basal lamina had been removed by means of an HCl-collagenase digestion method. No acinar plexus was seen to be formed by branches of the stomatogastric nerve that were associated with the gland. However, other branches of this nerve were clearly connected with a complex network of multipolar neurones on the surfaces of the anterior regions of both salivary reservoirs.
 ...
PMID:The salivary glands of the cockroach Nauphoeta cinerea (Olivier). A study of its innervation by light and scanning electron microscopy. 63 91


1 2 3 4 5 6 7 8 9 10 Next >>