Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.4.24.3 (collagenase)
18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Medullary and cortical tubular cells were prepared from rat kidneys with collagenase treatment. Arginine vasopressin (AVP) stimulated cyclic AMP production both in medullary and cortical cells with a dose-response relationship at concentrations ranging from 10 microU/ml to 10 mU/ml, whereas parathyroid hormone (PTH) and calcitonin did only in the latter. Using this medullary cell system, effects of acute changes in endogenous plasma AVP levels in vivo on its cyclic AMP responsiveness to AVP (10 mU/ml) in vitro were examined. Acute elevation of plasma AVP levels induced by ip injection of 20% (w/v) polyethylene glycol-isotonic saline solution 3 h prior to sacrifice resulted in a 33% decrease in cyclic AMP responsiveness to AVP (desensitization). More prolonged elevation of plasma AVP levels by water restriction for 48 h, on the other hand, increased the responsiveness by 38 to 81%, which was restored to basal levels by ad libitum intake of water for another 48 h (positive feedback regulation). These maneuvers did not alter the cyclic AMP responsiveness to PTH (10 micrograms/ml) in cortical cells. The results suggest that AVP-stimulated adenyl cyclase in rat renal medulla may be regulated by changes in endogenous AVP levels even within the physiological range.
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PMID:Altered cyclic AMP responsiveness to vasopressin in rat renal medullary dispersed cells by acute elevation of endogenous vasopressin. 629 51

Intracervical application of prostaglandin E2 in the late first trimester induces (1) softening of the cervix tissue; (2) increase in sulfated glycosaminoglycans (18 +/- 12%, mean +/- SEM); (3) no change in hyaluronic acid and water; (4) decrease in pepsin-extractable collagen, and (5) apparent decrease in collagenase. A high activity of collagenase in combination with a replacement of collagen with sulfated glycosaminoglycans may be of importance for the ripening process.
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PMID:Biochemical changes in human cervical connective tissue after local application of prostaglandin E2. 630 18

The activation energy (EA) and solvent-deuterium kinetic isotope effect (kH/kD) of human skin fibroblast collagenase were studied on the homologous human type I, II, and III collagens in both native and denatured states. Values for EA on human type I and II collagens in solution were 47,000 and 61,000 cal, respectively. The Arrhenius plot for type III collagen, unlike that for the other types, was characterized by a break in EA at approximately 26 degrees C. At temperatures below this point, EA was 42,500 cal; at higher temperatures, EA fell to 29,500 cal. This latter value, intermediate between type I collagen monomers and denatured random gelatin alpha chains, appears to result from a further opening in the already loosened helix of the type III collagen molecule in the region of the 3/4:1/4 collagenase cleavage site. The EA of trypsin on native human type III collagen was also measured and found to be 70,000 cal. This high value calls into question the role of serine proteases in the physiologic degradation of this substrate; a much higher energy expenditure was required for trypsin to cleave type III collagen than for the fibroblast collagenase. Reaction velocity on human collagen types I-III in solution was slowed 15-35% (kH/kD = 1.2-1.5) by the substitution of deuterium for hydrogen in the solvent buffer. This value was far lower than that observed following the aggregation of solution monomers into insoluble fibrils (kH/kD = 9). Denaturation of triple helical monomers into random gelatin alpha chains eliminated any slowing by deuterium, and kH/kD was 1.0 in all cases. Since the same peptide bond hydrolysis accompanies the cleavage of all these forms of the collagen substrate, it would appear that the role of water at the rate-limiting step of collagen degradation may not reside in the hydrolysis of a peptide bond per se, but rather may reflect the difficulty in transporting water molecules to the site of such catalysis, especially following fibril aggregation.
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PMID:Studies on the activation energy and deuterium isotope effect of human skin collagenase on homologous collagen substrates. 630 32

Rats were maintained under standardized conditions of food and water ad libitum and a lighting schedule of 12 h light/we h dark for seven days. Animals were sacrificed at 0500 and 1700 h and tissues were removed and washed. Isolated intact adrenal and pituitary cells were prepared by collagenase treatment. Using a sequential incubation procedure, the release of pituitary ACTH by hypothalamic acid extracts (CRF) was assayed by stimulation of corticosteroid secretion from isolated adrenal cells. Maximum stimulation of adrenal steroids was achieved with hypothalamic extracts and pituitary cells from rats sacrificed at 1700 h, and minimum values were obtained at 0500 h. Intermediate levels were obtained when hypothalamic extracts at one time point were incubated with pituitary cells at the other. The results substantiate the late afternoon peak level of hypothalamic and pituitary secretion occurring prior to the peak activity pattern of the rat.
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PMID:Hypothalamic and pituitary periodicity demonstrated by isolated rat adrenal cells. 631 42

Cervical biopsies obtained from 7 patients immediately following parturition induced by intracervical application of 0.5 mg prostaglandin E2 (PGE2) in viscous gel were compared with similar biopsies from 11 spontaneously delivered women. A DNP-peptide hydrolytic activity (collagenase) was significantly increased in cervical tissue from the PGE2-induced patients compared with controls. In patients with prompt clinical response, the increase was nearly twofold. No differences were found in the concentrations of water, sulfated glycosaminoglycans, hyaluronic acid, hydroxyproline or leukocyte elastase. Thus, PGE2-induced cervical priming seems to be associated with an increased collagenolytic activity.
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PMID:Increased postpartum collagenolytic activity in cervical connective tissue from women treated with prostaglandin E2. 631 47

Fibronectin, visualized in premolar pulps by indirect immunofluorescence, was abundant in the odontoblast layer, around blood vessels and in the core of the pulp. Similarity of alignment of fibronectin with the argyrophilic fibres and von Korff fibres was evident. Fibronectin was extracted from pulps after first removing blood by washing with water, confirmed by eventual negative reaction on alpha 2-macroglobulin. Extraction of fibronectin from this remaining tissue was most effectively achieved by treatment with collagenase or hyaluronidase, though in all cases some fibronectin remained, indicating that fibronectin in pulp is not exclusively associated with collagen and/or proteoglycans. The fibronectin quantified by electro-immunoassay and expressed as percentage of dry weight was 0.030 per cent in the water extract, 0.094 per cent in the collagenase extract and 0.109 per cent in the hyaluronidase extract. Twice as much fibronectin was extracted from the apical pulp as from the coronal and middle parts, in accord with earlier findings of a higher collagen content in the radicular part. It is suggested that with the loss of collagen type III during odontoblast differentiation and its reappearance with advancing vascularization of the dental papilla, the amount of fibronectin is similarly altered.
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PMID:Immunofluorescent localization and extractability of fibronectin in human dental pulp. 637 62

Alveolyn is a unique secretory glycoprotein of 250,000 molecular weight (MW) that is found in distal pulmonary secretions. Several glycoproteins of 130,000 MW, 80,000 MW, 62,000 MW, and 36,000 MW have also been found to be present in the alveolar secretions, and it was found that these glycoproteins were proteolytic fragments of the much larger molecular glycoprotein. It is also a major protein in human amniotic fluid, presumably a product of alveolar secretions. It is also secreted by a clone of pulmonary fetal type II cells. Preliminary results indicate that two of the proteolytic fragments of 62,000 MW and 36,000 MW contain alternate collagenous and noncollagenous domains in the same polypeptide chain. The presence of collagenous domains in these glycoproteins was also confirmed by their susceptibility to digestion with collagenase and the presence of Gly-Pro-Hyp-Gly-type sequence in the peptide chain. Very little is known about the tertiary structure of the protein, except that its fragments bind phospholipids and probably facilitate transfer of the lipid to air-water interfaces.
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PMID:Alveolyn--structure and source: a review. 638 49

Studies were carried out on the effect of triiodothyronine (T3) on the oxygen consumption of dispersed rat liver cells incubated for 2 hr at 37 degrees C. Thyroidectomized SD-NIH rats were kept on a low iodine diet with calcium chloride in the drinking water for 4 weeks or longer to assure hypothyroidism, verified by low serum thyroxine and T3 concentrations. Liver cells were obtained by portal vein perfusion with oxygenated collagenase-enriched Krebs-Ringer-bicarbonate buffer, after the method of Berry and Friend. Cell viability was evaluated by morphology, by trypan blue exclusion, and by biochemical parameters prior to 2-hr incubations with or without added hormone. The oxygen consumption of cell suspensions was measured with the Clark oxygen electrode after the 2-hr incubations at 37 degrees C with oxygenation of the flasks and alanine (5-10 mM) as substrate. In 31 experiments the oxygen consumption (QO2) was enhanced to 121% of control values with T3 in the medium at 3.3 nM ("physiological" level) and with an even greater effect (138% of control values) with 300-1000 nM T3 ("hyperthyroid" level). Cycloheximide at 100 microM was used to inhibit new protein synthesis by incubated hepatocytes. In 18 parallel experiments with cycloheximide blockade, no alteration of the stimulatory effect of T3 was evident. The results signify that incubated liver cells show an early response to thyroid hormone by extranuclear pathways that do not require new protein synthesis.
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PMID:Rapid thyroid hormone action in vitro in the absence of new protein synthesis. 653 49

Transport of alprostadil (prostaglandin E1) and dinoprost (prostaglandin F2 alpha) was studied in enzymatically dispersed normal and streptozocin-treated rat hepatocytes prepared by collagenase perfusion. Cell suspensions incubated at 37 degrees were sampled at time intervals for a period of 5 min and the supernatant analyzed for prostaglandins after centrifugation. The data analysis employed a theory and a model for solute transfer at the cell membrane-water interphase. Biophysical parameters such as the effective partition and the apparent permeability constants were used to define the transport mechanism. The apparent permeability coefficient of alprostadil and dinoprost transfer through normal hepatocytes was calculated to be 5 X 10(-3) and 3 X 10(-3) cm/sec with a mean partition coefficient of 1345 and 764 for both solutes, respectively. The permeability coefficient of alprostadil and dinoprost transfer through diabetic hepatocytes were 3 X 10(-3) and 2 X 10(-3) cm/sec with partition coefficient of 572 and 206, respectively. The results showed differences in prostaglandin transport between normal and diabetic hepatocytes, resulting from morphological and lipid alteration in the cytoplasmic membrane.
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PMID:Transport of prostaglandins through normal and diabetic rat hepatocytes. 657 77

A three step extraction procedure was carried out on intact hamster molar tooth germs in vitro labelled with 32PO4 and/or 3H-proline, in order to quantify separately the synthesis of dentine matrix (collagen) and the proline rich enamel matrix proteins. The extraction was based on the high solubility of the proline rich enamel matrix proteins compared with the relatively insoluble dentine matrix collagens. Pretreatment with 10% trichloroacetic acid (step 1) demineralized and removed the non-incorporated amino acids and/or small sized peptides. A consecutive water extraction (step 2) removed a large percentage of the phosphorylated amelogenins as assessed by SDS-urea-polyacrylamide-electrophoresis and amino acid analyses. Collagenase digestibility data showed that only small amounts of collagens were present in this extract. Further extraction with 10% formic acid (step 3) released only small amounts of amelogenins from the explants but also increased contamination with collagens and another predominantly low molecular components. Most of the 3H-activity remaining in the residues was found in the collagenase labile material and was considered to be an appropriate measure for production of dentine collagens. On the other hand, the residues also contained small amounts of 3H-labelled material with the same electrophoretic mobility as amelogenins but had much more 32P-activity than the amelogenins derived from the water and formic acid extracts. It is suggested that this material in the residues probably contains the crystal bound enamel matrix proteins.
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PMID:Biosynthesis of tooth germ proteins in vitro: a fast quantitative extraction of amelogenins from intact hamster molar tooth germs. 659 32


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