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Enzyme
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Enzyme
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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)
A new technique is described whereby viable infiltrating cells can be freed from skin biopsy specimens. The specimens are incubated with
collagenase
and then mechanically disaggregated. The liberated cells are still suitable for immunological and morphological study. Using this method, the nature of the dermal infiltrate in patients with skin reticuloses was compared with that in lichen planus. A predominance of T cells was found in mycosis fungoides, the Sezary syndrome, and lichen planus, and of B cells in non-Hodgkin lymphomas.
Br J Dermatol 1975
Sep
PMID:A method of liberating living cells from the dermal infiltrate. 17 4
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.
Am J Physiol 1975
Sep
PMID:Dispersed rat parotid acinar cells. I. Morphological and functional characterization. 17 40
Substrate specificity of purified tadpole
collagenase
(
EC 3.4.24.3
) has been studied using eleven synthetic peptides. A pentapeptide, t-butyloxycarbonylprolylalanylglycylisoleucylalanine amide, was susceptible to the action of the enzyme and an octapeptide, acetylprolylglutaminylglycylisoleucylalanylglycylglutaminylarginine ethyl ester, was proposed to be the best substrate for vertebrate collagenase among the peptides tested.
Biochim Biophys Acta 1976
Sep
14
PMID:Substrate specificity of vetebrate collagenase. 18 80
Mechanical and enzymatic methods of disaggregating tumors were studied with the goals of (1) minimizing cell losses while (2) maintaining functional and surface membrane markers needed to objectively identify inflammatory cells (IC)1 in resultant suspensions. Application of the principles and methods described makes accurate estimation of the percentage of each IC type present in neoplasms possible for the first time. Compared to purely mechanical means of disaggregating tumors, all enzyme mixtures tested markedly increased yields of viable cells/g neoplasm. Best results were obtained with a combination of
collagenase
and a protease of broader substrate range (alpha chymotrypsin, papain, pronase or trypsin). The combination of enzymes that gave the highest yields with the least effect on inflammatory cell markers was trypsin,
collagenase
and DNAse (TCD). Because mechanical injury appeared to be the greatest single cause of cell loss (the enzymes themselves had little direct effect), potential sources were identified and either eliminated or minimized. With TCD, depending on the tumor system, cell recovery (measured as DNA recovered in cell suspensions) was as high as 50% and yields were as much as 6.9 X 10(8) viable cells/g tumor. Complete disaggregation was not required to obtain representative IC populations from tumor fragments. Neutrophils, eosinophils and mast cells from disaggregated neoplasms were counted in Giemsa stained cytocentrifuge preparations based on their unique morphologic appearances. Macrophages were identified by their capacity to phagocytose zymosan, a function which proved highly resistant to the effect of enzymes. Flourescent microscopic identification of brain associated thymus antigen (BATA) allowed quantification of T lymphocytes, since this marker was virtually unchanged by enzyme exposure. Surface immunoglobulin (Ig) was stripped from B lymphocytes most rapidly by pronase and chymotrypsin, slowly by trypsin and papain, and not at all by
collagenase
. Ig positive cells therefore could be quantified in suspensions generated by
collagenase
or very short (20 min) exposure of fragments to trypsin.
Int J Cancer 1976
Sep
15
PMID:Inflammatory cells in solid murine neoplasms. I. Tumor disaggregation and identification of constituent inflammatory cells. 18 47
A method for the detection of collagen-anti-collagen immune complexes using
collagenase
of bacterial origin is described. Anti-collagen-titers are determined in passive haemagglutination before and after
collagenase
digestion of samples containing preformed immune complexes. An increase in anti-collagen titers following the enzymatic treatment suggests the presence of collagen-anti-collagen immune complexes. Both solbule and carrier-bound
collagenase
proved to be equally effective in the digestion of complex-bound collagen, if in vitro prepared collagen-anti-collagen complexes were investigated. Original titers of partially or totally inhibited antisera to collagen could be completely restored by this method.
Z Immunitatsforsch Immunobiol 1976
Sep
PMID:Identification of collagen-anticollagen immune complexes by collagenase-digestion. 18 2
Macrophages from mineral oil-stimulated mice produce
collagenase
at a constant rate over several days in culture. Phagocytosis of latex does not increase production of enzyme. Gel electrophoretic and electron microscopic analyses indicate that the specificity of the macrophage enzyme is similar to that of other previously characterized mammalian collagenases.
Biochim Biophys Acta 1976
Sep
24
PMID:Production of collagenase by mouse peritoneal macrophages in vitro. Characterization of sites of cleavage of tropocollagen. 18 32
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.
Brain Res 1976
Sep
17
PMID:Enzymic preparation of neurosecretosome- and pituicyte-enriched fractions from the rat neurohypophysis. 18 63
Collagenase from Clostridium histolyticum induced haemorrhages when applied to the surface of dog lung; it exerted a similar effect on mouse lung when injected intrathoracically. Injected into rat paws, bacterial
collagenase
induced haemorrhage and oedema. Effects of
collagenase
were prevented by several procedures that inhibit collagenolytic activity (heating at various temperatures and incubation with metal-complexing agents such as EDTA, penicillamine and dithiothreitol). Protein protease inhibitors, dexamethasone and standard acidic anti-inflammatory drugs had only a slight or no effect on
collagenase
-induced haemorrhages; dexamethasone and acidic anti-inflammatory drugs blocked
collagenase
-induced oedema. Inhibition of endogenous kinin-releasing mechanisms by administration of hexadimethrine, a recognized inhibitor of the activation of clotting Factor XII, and depletion of kininogen by administration of carrageenin blocked
collagenase
-induced oedema. Collagenase did not increase permeability of rat skin vessels, nor did it release potential inflammatory mediators, such as bradykinin or prostaglandins, from plasma or platelets. Bacterial
collagenase
-induced haemorrhage presumably resulted from enzymatic destruction of membranous structures; at least a portion of the inflammatory response may be due to activation of a kinin-like system.
Agents Actions 1976
Sep
PMID:Haemorrhagic and inflammatory properties of collagenase from C. histolyticum. 18 2
Increased aortic and liver prolyl hydroxylase activity has been suggested as an early biochemical indicator of the fibrotic changes which occur in rabbits with injury induced arteriosclerosis. Daily administration of epinephrine (0.025-0.050 mg/kg, i.v.) and thyroxine (0.050 mg/kg, i.p.) to rabbits for 3 weeks produced aortic fibrous plaques with a 4-fold increase in aortic prolyl hydroxylase and also a 5-fold increase in liver prolyl hydroxylase. Histopathologically, the livers of these rabbits show subcapsular areas of necrosis. When total prolyl hydroxylase related antigen was measured. the increase in liver prolyl hydroxylase activity accounted for only a small portion of the total prolyl hydroxylase antigen. However, in the aorta a majority of the increase in antigen is due to the increased amount of enzyme. DNA content per aorta was unchanged and RNA content increased in the aortic tissue of the arteriosclerotic rabbits. However DNA and RNA levels increased 60% in the livers of arteriosclerotic rabbits. In vitro incorporation of radioactively labeled proline into
collagenase
digestable protein was at least 2-fold greater in aorta and liver minces from arteriosclerotic rabbits. Michaelis--Menten kinetic parameters were obtained for the liver prolyl hydroxylase purified by affinity chromatography from arteriosclerotic rabbits. The Km for the enzyme from treated animals was not significantly different from control. However, the Vmax of the enzyme purified from diseased liver was 4-fold greater when compared to controls.
Atherosclerosis 1976
Sep
PMID:Increased collagen synthesis and the kinetic characteristics of prolyl hydroxylase in tissues of rabbits with experimental arteriosclerosis. 18
The mechanism of albumin biosynthesis was studied in Morris hepatoma 5123tc in vivo and in hepatoma cell suspensions obtained by solubilizing the intercellular matrix with
collagenase
and hyaluronidase. In the in vivo experiments, L-[-14C]leucine was injected i.v. into rats bearing hepatomas in the muscles of both hind legs. After 14 min, tumors were removed and homogenized. A protein fraction quantitatively precipitable with antialbumin was isolated from the homogenate by acetone fractionation and precipitation with antiserum against serum albumin. This protein fraction was not homogeneous. With the use of 3 consecutive chromatographies on diethylaminoethyl cellulose, a very highly radioactive albumin-like protein could be separated from a large amount of only slightly radioactive albumin. In hepatoma cell suspensions incubated with L-[1-14C]leucine followed by a chase with excess nonradioactive L-leucine, radioactivity was incorporated first into the albumin-like protein and transferred thereafter into albumin, suggesting that albumin was synthesized via the albuminlike protein as precursor. In vivo, 1.8% of newly synthesized hepatoma protein was albumin or its precursor, compared with 1.2% in cell suspensions.
Cancer Res 1976
Sep
PMID:Biosynthesis of albumin via a precursor protein in Morris hepatoma 5123tc. 18 40
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