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:3.4.21.4 (trypsin)
42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

By treatment of chorioallantoic membranes from embryonated eggs with collagenase and hyaluronidase before the conventional application of trypsin cells could be grown in culture which supported growth of a large variety of myxoviruses, herpesviruses, avian reoviruses and the infectious bronchitis virus of chickens. The cultures could be used for sensitive plaque assays and neutralization tests.
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PMID:In vitro cultivation of cells from the chorioallantoic membrane of chick embryos. 16 93

1. An activator catalysing specifically conversion of latent forms of human leucocyte collagenase and gelatin-specific protease into the active forms, has been isolated from rheumatoid synovial fluid and purified 55-fold with a yield of 16%. 2. Molecular weight of the activator is about 35 000. 3. The activator is thermolabile, and is irreversibly inactivated at pH below 5.5 or in the presence of low concentrations of trypsin or papain; it is resistant to the action of lysozyme, hyaluronidase, diisopropylfluorophosphate, soybean trypsin inhibitor, p-chloromercuribenzoate, iodoacetamide and dithiothreitol. 4. The activator did not show any activity towards collagen, gelatin, casein, haemoglobin, histones, elastin or p-phenylazobenzyloxycarbonyl-peptide.
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PMID:Isolation, purification and properties of a factor from rheumatoid synovial fluid activating the latent forms of collagenolytic enzymes. 17 Jul 64

Morphologically and functionally intact acinar cells have been obtained from the rat parotid gland through enzymatic dispersion with pure collagenase, hyaluronidase, and trypsin as well as mild mechanical forces. Cell yields of 30-50% of the original tissue weight with over 95% acinar cells were accomplished. The cells in suspension assumed a more or less spherical shape but the intracellular polarity of organelle distribution was maintained. The cells in suspension at 37 degrees C maintained stable monovalent cationic composition but lost potassium and gained sodium rapidly upon exposure to ouabain, 10(-5) M. The intracellular amylase concentration and the patterns of secretion of amylase and of synthesis of cyclic AMP by the cells in response to adrenergic stimulation with epinephrine or isoproterenol were comparable to those of the intact gland in situ. In addition, the cells showed good O2 consumption and maintained it constant for periods up to 8 h. These cells could be used as experimental tools for in vitro studies of receptor physiology and biochemistry, cell membrane function, cellular secretory mechanisms, and other parameters of exocrine gland cell physiology.
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PMID:Dispersed rat parotid acinar cells. I. Morphological and functional characterization. 17 40

The ascites form of a chemically induced guinea pig hepatoma, line-10, was resistant to killing in vitro by xenogeneic antibody and guinea pig complement. Pretreatment of line-10 cells with certain proteolytic enzymes rendered tham susceptible to the killing action of antibody and guinea pig complement. The effects of enzyme pretreatment were dependent on enzyme concentration, temperature, and could be blocked by addition of competitive or non-competitive inhibitors. The effect of the enzyme treatment could reversed by incubating the treated cells at 37 degrees C (but not at 0 degrees C), in the absence of the enzyme. Effective enzymes included ficin, bromelain, pronase, elastase, papain, trypsin, collagenase, lipases type I and type VI, and the neuraminidase preparation isolated from Clostridium perfringens. The activity of the lipase preparations and the neuraminidase preparation isolated from Clostridium perfringens appeared to be caused by proteolytic enzyme contamination. Enzyme preparations that proved ineffecitve in rendering the line-10 cells sensitive to killing by antibody and guinea pig complement included DNase, RNase, beta-glucuronidase type 6A or type B10, hyaluronidase type V or type VI, and pectinesterase.
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PMID:Lysis of tumor cells by antibody and complement. VI. Enhanced killing of enzyme-pretreated tumor cells. 17 70

Viable and functional luteal cells were prepared, using a combination of hyaluronidase, collagenase, and a low concentration of trypsin in a Dulbecco's modified Eagle medium containing 0.5% bovine serum albumin and 3.3 mM Ca++, from corpora lutea taken from 2-day pregnant rats. The viability and functional capacity of the dispersed cells were evaluated by electronmicroscopy and by measuring steroidogenic capicity during perifusion. Dispersed luteal cells previously exposed in vivo to biphasic prolactin (PRL) surges were found to respond during perifusion to as little as 0.5 ng/ml LH by increased steroid secretion. The net progesterone synthesis and secretion remained elevated over a time course of 2 1/2 hours perifusion, and the magnitude of the luteotropic stimulation was dose dependent on LH. However, luteotropic stimulation of LH could not be maintained beyond 2 1/2 h without renewed (in vitro) PRL exposure. PRL by itself maintained the low initial secretion rate of progesterone but demonstrated no stimulatory effect. Different steroidogenic responses were noted during the in vitro administration of LH alone and the administration of LH plus PRL. In the former case, the decreasing rate of progesterone secretion was accompanied by an increasing 20 alpha-dihydroprogesterone secretion, suggesting that luteal 20 alpha-hydroxysteroid dehydrogenase activity was not suppressed. In the latter case, progesterone secretion was maintained and 20 alpha-dihydroprogesterone secretion fell suggesting an inhibitory action by PRL against 20 alpha-hydroxysteroid dehydrogenase activity. Dispersed luteal cells, preincubated at 36 C in medium containing only PRL, retained viability and functional capacity in response to LH-PRL stimulation for periods of time up to 48 h. Preincubation with LH alone did not prolong cell viability.
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PMID:Luteotropic regulation of dispersed rat luteal cells in early pregnancy. 17 93

A microcellular dispersion procedure for the rat neurohypophysis was developed, comprising tissue softening and dissociation using a special sieving sytringe. In preparatory studies the influence of mesh width, and treatment with trypsin, pronase or collagenase-hyaluronidase was investigated using light and electron microscopy, as well as with microchemistry by means of protein and lactate dehydrogenase activity determinations. Trypsinization gave the best results. In the final adopted procedure, 3 incubated neurohypophyses were sequentially sieved through a 200- and a 50-mum mesh. The resulting 50-mul dispersion was found to contain numerous ultrastructurally well-preserved pinched-off axonal endings (neurosecretosomes), and pituicytes often revealing processes. On the basis of DNA and oxytocin assays 11% of the pituicytes and 28% of the axonal cytoplasm were recovered. Oxytocin immunofluorescence microscopy showed hormone within the neurosecretosomes, but often also in the cytoplasm of pituicytes. Microdensity gradient centrifugation was performed on neurohypophyseal disperions, in order to obtain fractions enriched for neurosecretosomes and pituicytes. Fractions were characterized by means of phase contrast, oxytocin immunofluorescence and electron microscopy, as well as by oxytocin and DNA assays as respective markers. With a 10:14:22% (w/v) Ficoll gradient, fractions were obtained for which the relative purification was by a factor of 4 on the basis of DNA/oxytocin ratios.
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PMID:Enzymic preparation of neurosecretosome- and pituicyte-enriched fractions from the rat neurohypophysis. 18 63

Surface antigens of HeLaHVJ cells, a cell line persistently infected with HVJ, were studied by fluorescent antibody staining. After absorption with concentrated HVJ virions and HeLa cells, anti-HeLaHVJ antiserum was able to demonstrate specific surface fluorescence on HeLaHVJ cells, while this serum no longer reacted with original HeLa cells nor with HVJ virions. During cytolytic infection of HeLa cells with HVJ, this specific surface antigen appeared at an early stage of infection prior to the appearance of newly synthesized HVJ viral antigens and moreover appeared in spite of the inhibition of viral protein synthesis. This antigen was detected neither on HeLa cells infected with other myxoviruses except HVJ nor on various other kinds of cells infected with HVJ. The specific surface antigen was still found on the HeLaHVJ cell surface after incubation at 38 degrees C for two days, while HVJ structural antigens on the cell surface no longer could be detected. Mild short-term treatment of HeLa cells with trypsin, neuraminidase from vibrio cholerae, phospholipase-C and hyaluronidase failed to expose specific antigen. The antigen was distinguishable from the Forssman and human blood type antigens. The mechanism of appearance of a new antigen on the surface of HeLaHVJ cells remains unclear.
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PMID:Surface antigens on HeLa cells persistently infected with HVJ (Sendai virus). 18 62

Normal and premalignant mouse mammary epithelial cells can be prepared in high yields by collagenase dissociation of minced glands followed by a brief, differential centrifugation to remove contaminating fibroblasts and fat cells. The major difficulties in preparing pure cultures in quantity are 1) incomplete dissociation of gland material, and 2) cell death during enzymatic digestion. These problems are eliminated by careful selection of collagenases for dissociation. Normal and premalignant mammary epithelial cells are morphologically indistinguishable from malignant mouse mammary epithelial cells in primary monolayer cultures. In addition, the growth rates and saturation densities achieved by normal mammary epithelial cells are indistinguishable from those of malignant mammary epithelial cells in primary culture. In both cases, a monolayer of cells is preserved with no evidence of focal overgrowth. Malignant adenocarcinoma mammary cells can however be distinguished from normal mammary epithelial cells by virtue of differences in their surface interactions with concanavalin A. A hemadsorption assay using Con-A-coated erythrocytes was the most sensitive indicator for these differences. In hemadsorption assays malignant mammary epithelial cells were half-maximally reactive with 2.5 mug/ml concanavalin A, while normal cells were completely unreactive even at concanavalin A concentrations five-times higher. Premalignant mammary epithelial cells were as reactive as malignant mammary epithelial cells in the hemadsorption assays. Hemadsorption of malignant cells was observed in primary and secondary cultures of epithelium as well as in cell lines. Malignant cells forming mammary adenocarcinomas were as highly reactive as malignant cells forming scirrhous carcinomas. Malignant cells not releasing mammary tumor virus (MuMTV) were as reactive as cells releasing that virus. Adsorption of concanavalin-A-coated erythrocytes to normal mammary epithelial cells could be induced by brief treatment of cell monolayers with hyaluronidase. Exposure of active sites was not affected with either trypsin or collagenase. Our results show that while the growth of malignant cells does not serve to distinguish them from normal cells in monolayer culture, surface changes do exist which can be identified by differences in concanavalin A reactivity. Since the earliest transformants identifiable in vivo (premalignant) have undergone conversion of the surface marker, concanavalin-A-mediated hemadsorption provides a sensitive measure for mammary epithelial cell transformants in vitro.
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PMID:Markers to distinguish normal and neoplastic mammary epithelial cells in vitro: comparison of saturation density, morphology and concanavalin A reactivity. 18 59

A large amount of plasma low density lipoprotein is present in human aortic intima, and this can be removed and measured by electrophoresis directly from the minced tissue into an antibody-containing gel. We now find that, in addition to this electrophoretically mobile lipoprotein, there is an immobilized lipoprotein fraction than can be released from lesions by incubation of the tissue sample with plasmin or other proteolytic enzymes after the mobile lipoprotein has been removed. The concentration of immobilized lipoprotein is highly correlated with the concentration of the residual cholesterol (not mobile on electrophoresis) that has accumulated in the tissue (r = 0.702; P less than 0.001). Thus, in normal intima and early gelatinous lesions it is about 15% of the concentration of mobile lipoprotein, whereas in the atheroma lipid layers of fibrous or gelatinous plaques it may be 2 or 3 times greater than the concentration of mobile lipoprotein. This suggests that immobilization of plasma lipoprotein is an intermediate step in the irreversible deposition of extracellular cholesterol in atherosclerotic lesions. Incubation with plasmin allowed maximum release of lipoprotein: plasmin = crude collagenase greater than trypsin greater than "pure" collagenase greater than chondroitinase ABC in order of their relative effectiveness. The concentration of immobilized lipoprotein was significantly correlated (r = 0.793; P less than 0.001) with the concentration in the tissue of fibrin or other insoluble derivatives of fibrinogen ("fibrin"). In aliquots of lesions incubated with varying amounts of plasmin for varying times there was a constant relation between release of lipoprotein and release of fibrin-degradation products. Together, these findings suggest that the lipoprotein is associated with insoluble "fibrin". This appears to be of considerable clinical interest, suggesting a synergism between lipoprotein and fibrinogen in the accumulation of lipid in lesions.
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PMID:The release of an immobilized lipoprotein fraction from atherosclerotic lesions by incubation with plasmin. 18 79

An investigation was conducted on the effect of formocresol treatment of the aqueous extractability and enzymatic susceptibility of excised implant tissue. The treated tissue demonstrated a decreased solubility and a diminished digestibility by trypsin, pepsin and collagenase. However, its reactivity toward hyaluronidase showed little alteration.
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PMID:The effects of formocresol on rat sponge implant tissue: a biochemical study. 20 Jun 37


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