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:3.4.21.1 (chymotrypsin)
10,938 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A procedure for dissociation of the guinea pig pancreas into individual cells is described which employs enzymatic digestion with pure collagenase, chymotrypsin, and hyaluronidase, utilizes an interposed chelation of divalent cations by EDTA, and is terminated by gentle shearing. Yields of cells are 50-60%, based on DNA recovered. The population comprises approximately 95% exocrine cells, the remainder consisting of endocrine, duct, and vascular endothelial cells. The exocrine cells, though spherical, retain the structural attributes of their in situ counterparts, including differentiation of the plasmalemma into zones corresponding to the former apical and basal plasmalemma, polarized distribution of organelles indicated by fields of zymogen granules in the cytoplasm underlying the former apex, central location of the Golgi complex, and placement of the rough endoplasmic reticulum and nucleus in the former basal pole of the cell. Electron microscope study of the effects of individual treatments used during dissociation indicates that digestion of basement membrane and collagen is solely due to collagenase activity and that separation of desmosomes (and possibly of zonulae adherentes) results only from exposure to low [Ca(++)] and EDTA and is not effected by the enzymes used. Gap junctions are resistant to enzymes and EDTA; tight junctions resist enzyme treatment but undergo rearrangement upon exposure to EDTA. Both junctions require mechanical shear for complete cell separation. Neither chymotrypsin nor hyaluronidase produces visible alterations in stromal or junctional elements. Dissociation requires the concerted action of enzymes, chelation of divalent cations, and mechanical shear, since the individual treatments are alone ineffective.
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PMID:Studies on dispersed pancreatic exocrine cells. I. Dissociation technique and morphologic characteristics of separated cells. 437 77

Explants of normal skin fail to react in direct immunofluorescence tests with stratum corneum antibodies. However, upon stripping with cellophane tape, the horny layer of such explants react in tissue culture. Swabbing of skin explants with ether and chloroform converts stratum corneum antigen (SCAg) from a nonreactive to a reactive form. Treatment with methanol, acetone or phosphate-buffered saline failed to bring about such a conversion. Treatment of skin explants with hyaluronidase and phosphilipase A converst SCAg of at least some skin explants to a reactive form. Treatment with trypsin, chymotrypsin and plasmin abolished the reactivity of SCAg upon prolonged incubation. However, upon short incubation with plasmin, SCAg was converted to a reactive form.
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PMID:Studies in immunodermatology. IX. Effect of organic solvents and enzymes on the reactivity of stratum corneum antigens. 622 Sep 75

A procedure for dissociation of the nasal salt glands of the domestic duck, Anas platyrhynchos, into suspensions of individual cells has been developed. This technique employs enzymatic digestion with collagenase, hyaluronidase, and chymotrypsin; divalent cation chelation with EDTA; and gentle mechanical dispersion. Average cellular yields of 39 and 26% based on DNA recovered were obtained from the glands of freshwater- and saline-adapted ducks, respectively. Epithelial secretory cells comprised 60-80% of the cell suspensions with the remainder of the populations consisting of endothelial cells, fibroblasts, and blood cells. The dissociated cells were viable as judged by trypan blue exclusion (80-100%, maintenance of ultrastructural integrity, and retention of responsiveness to secretagogues and metabolic inhibitors. Methacholine chloride (0.5 mM) stimulated oxygen consumption by suspensions of both freshwater- and saline-adapted cells, whereas ouabain (0.05 mM) abolished the methacholine-stimulated respiratory response. These cell suspensions provide a promising system for the in vitro study of secretory mechanisms in the avian salt gland.
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PMID:Dissociation of avian salt gland: separation procedures and characterization of dissociated cells. 624 10

The arachidonic acid pathway plays an important role in many inflammatory reactions. Current evidence suggests that platelets can play a central part in host inflammation. Since microfilariae are mobilized into the bloodstream following diethylcarbamazine (DEC) treatment, we have studied the effects of Onchocerca cervicalis cuticle preparations on equine platelet aggregation. The authors have found that O cervicalis cuticular preparations can induce platelet aggregation in vitro. Furthermore, this activity was abrogated by treatment with collagenase and not hyaluronidase, elastase, or alpha-chymotrypsin. When this evidence is viewed collectively with the evidence for in vivo parasite cuticular damage following DEC treatment, it becomes entirely plausible that the cuticular damage may indeed reveal a platelet-reactive surface, thus permitting platelet-parasite binding to occur. This binding would result in platelet aggregation and the generation and release of platelet-derived arachidonate metabolites. These metabolites may play a very critical role in the development of the described pathologic sequelae observed following DEC treatment. Field studies using cyclooxygenase and lipoxygenase inhibitors might therefore be very efficacious in decreasing the frequency of side effects due to DEC or other potentially effective drug regimens.
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PMID:Aggregation of equine platelets by Onchocerca cervicalis collagen. 629 6

We have used the enzyme elastase to remove the basal lamina of epithelia from two insects: the upper Malpighian tubules of Rhodnius prolixus and imaginal discs of Drosophila melanogaster. Removal of the basal lamina was confirmed using scanning and transmission electron microscopy. Use of the technique on the Malphighian tubules of Rhodnius reveals for the first time the three-dimensional organization of the circumferential folds of the basal plasma membrane. Elastase is much more effective in removing the basal lamina than are the enzymes hyaluronidase, collagenase, and chymotrypsin, either alone or in combination. Following elastase treatment, cells of the Malpighian tubules dissociate with only mild mechanical agitation into single, viable cells. Treatment with elastase removes the basal laminae of imaginal discs of Drosophila and accelerates evagination as has been previously described for trypsin. To obtain single cell preparations from elastase-treated imaginal discs, mechanical stirring in Ringer low in Ca2+ was required. In addition to its usefulness in cell isolation, elastase treatment allows examination of the effect of removal of basal laminae on the physiology and development of insect epithelia.
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PMID:Removal of insect basal laminae using elastase. 643 33

Culture-produced subendothelium (SE) has been prepared from cultured porcine aortic endothelial cells (ECs) by a rapid freeze-thaw, ice-shearing method. En face preparations of this in situ SE material are essentially free of intact or damaged cells and cell debris and consisted of an extensive meshwork of microfibrillar and amorphous material. Washed porcine platelets reacted extensively with this SE material and were associated with the SE as single adherent platelets, single spread platelets, and varying-sized platelet aggregates or 'microthrombi'. Platelet aggregates were associated only with the damaged or frayed edges of the SE, and the platelets had undergone extensive SE-induced contraction and degranulation, as indicated by transmission electron microscopy. Platelet-SE interaction was affected by pH, calcium, platelet concentration, rapid shaking and exposure time. Platelet-SE interaction was significantly enhanced by the addition of 0.1-1% citrated plasma or purified porcine F.VIIIR:WF. Pretreatment of the SE with thrombin, elastase, neuraminidase or hyaluronidase had no effect on platelet-SE interaction, whereas pretreatment with pepsin, plasmin, trypsin, alpha-chymotrypsin or collagenase decreased or completely abolished all platelet-SE interaction. Extraction of the SE with various solutions (high salt, detergents, etc.) had no effect on platelet-SE interaction, only solutions containing sodium dodecyl sulfate completely abolished all platelet-SE interaction.
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PMID:Culture-produced subendothelium. I. Platelet interaction and properties. 680 25

Urinary trypsin inhibitor (UTI) has a multipotent inhibitory effect on proteases such as trypsin, chymotrypsin, plasmin, human leukocyte elastase, or hyaluronidase. UTI can bind easily to its receptors on various types of tumor cells (human ovarian cancer HOC-I cells, human choriocarcinoma SMT-cc1 cells, and murine Lewis lung carcinoma 3LL cells). Our results show that the UTI receptors of some tumor cells have a possible role in modulating plasmin activity on the cell surface and prevention of tumor cell invasion and metastasis (H. Kobayashi et al., J. Biol. Chem., 269; 20642-20647, 1994). UTI interacts with tumor cells as a negative modulator of the invasive cells. We investigated whether this effect may be mediated by UTI binding to the cell surface receptors. In addition, the role of peptide sequences from each UTI domain and their interaction with tumor cells were investigated. UTI derivatized with biotin or FITC was taken up by tumor cells in a dose-dependent manner. This cell association was inhibited with a monoclonal antibody D1, which specifically recognizes NH2 terminus (domain I) of UTI. The binding was inhibited by fluid phase UTI, but not HI-8, COOH terminus (domain II) of UTI, suggesting that UTI binds to cells through a site in the UTI domain I. Furthermore, we found that UTI, HI-8 and a number of peptides containing Arg-Gly-Pro-Cys-Arg-Ala-Phe-Ile promoted the inhibition of tumor cell invasion. This site corresponds to the plasmin-inhibiting domain within HI-8. The possibility that UTI binding to tumor cells might be involved in the prevention of tumor cell invasion in vitro was excluded since HI-8, lacking domain I, promotes the inhibition of tumor cell invasion with essentially the same affinity as UTI. All these data allow us to conclude that inhibition of tumor cell invasion is mediated by domain II, which possesses anti-plasmin activity.
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PMID:Inhibition of tumor cell invasion through matrigel by a peptide derived from the domain II region in urinary trypsin inhibition. 772 51

We describe the clinical history, histopathology and treatment of a two and a half year old boy. He presents with a chronic, unilateral and (pseudo) membranous conjunctivitis, preceded by ear-nose-throat problems and arthritis. The case was considered to be a ligneous conjunctivitis. Treatment consisted of repeated removal of the membranes, combined with topical hyaluronidase, alpha-chymotrypsin, cyclosporin, heparin and antibiotics, and was deceiving.
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PMID:A puzzling case: conjunctivitis lignosa? 981 96

The clinical, histopathologic features, and treatment outcomes in 3 patients with ligneous conjunctivitis are described. Bilateral, idiopathic membranes occurred in the palpebral conjunctiva in 2 patients. In 1 patient, unilateral conjunctival changes occurred in the bulbar conjunctiva, at the site of pterygium excision. Treatment included topical hyaluronidase, chymotrypsin, heparin, and cyclosporine and surgical excision with limited or no success. In one patient, conjunctival autografting from the normal fellow eye resulted in pseudomembrane formation at the donor site in the previously unaffected eye. Histopathological evaluation of excised membranes revealed the presence of amorphous eosinophilic hyaline material and chronic inflammatory cells. Immunohistochemical study revealed a predominance of T-lymphocytes. This case series confirms the recalcitrant clinical course of ligneous conjunctivitis. Conventional treatment modalities described in literature were not useful in the management of this condition. Surgical manipulation of the unaffected fellow eye in patients with unilateral disease can result in pathologic conjunctival changes, and is best avoided.
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PMID:Ligneous conjunctivitis: a clinicopathologic study of 3 cases. 1067 63

The high molecular weight arylamidase-alkaline phosphatase-complex from rat kidney microsomes [1] was carefully dissociated by means of treatment with several hydrolytic enzymes or by acidification. Trypsin, chymotrypsin and pronase cause a selective solubilization of the enzymes discernible at their different electrophoretic mobility in polyacrylamide gel. The lower migrating zone represents phosphatase, the faster migrating zone shows arylamidase activity (molecular weights 180,000 and 172,000, respectively). Incubation of the complex with papain, lipase, neuraminidase or hyaluronidase and incubation at acid conditions (pH optimum 5.0) in the absence of any enzyme also yields in the appearance of two protein bands. In contrast to the alkaline hydrolases the acid hydrolases, the pH 5-treatment and with a certain degree also the lipase liberate a second arylamidase zone lying in the phosphatese containing zone during polyacrylamide gel electrophoresis. Treatment with SDS and subsequent SDS-polyacrylamide gel electrophoresis also results in a dissociation of the complex, but only in one protein fragement (approx, molecular weight 205,000).
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PMID:??? 1194 35


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