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

---

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

Evidence is presented indicating that the chemically transformed AKR-MCA and C3H/MCA-58 murine cell lines produce "transforming growth factor(s)" capable of inducing a transformed morphology and the ability to grow in soft agar in nontransformed, anchorage-dependent indicator cells. Serum-free medium conditioned by exposure to the chemically transformed cells was chromatographed on a Bio-Gel P-60 column after dialysis and lyophilization. Using the nontransformed mouse AKR-2B cells as the indicator cells, a peak of soft agar growth-stimulating activity was detected in the molecular weight range of 10,000 to 12,000. The soft agar growth-stimulating activity in pooled fractions from the AKR-MCA cells was shown to be trypsin and dithiothreitol sensitive and relatively heat stable; the activity was not destroyed by heating to 56 degrees for 30 min or to 100 degrees for 3 min. The pooled material also caused stimulation of growth in the soft agar of rat NRK cells and stimulation of DNA synthesis in the AKR-2B cells. The quantity required to give significant competition for binding to the epidermal growth factor receptor was about one order of magnitude greater than that required for stimulation of soft agar growth. Further separation of these polypeptide(s) by carboxymethylcellulose chromatography revealed three apparent peaks of soft agar growth-stimulating activity. Epidermal growth factor receptor-competing activity cochromatographed with the early minor soft agar growth-stimulating peak, whereas the two major peaks of soft agar growth-stimulating activity had no associated detectable competition for epidermal growth factor binding to its receptor. The data indicate that at least a major portion of the transforming growth factors produced by the chemically transformed cells is different from those described previously in murine sarcoma virus-transformed mouse cells and human tumor cells.
...
PMID:Transforming growth factor production by chemically transformed cells. 626 69

Sarcoma virus transformed rat kidney cells, NRK[MSV-MLV] cells, and their non-transformed counterparts, NRK cells, were repeatedly subcultured in medium supplemented with 1 mM 2-deoxy-D-glucose (dGlc). These dGlc-grown cells exhibited alterations in glycosylation of surface proteins. Gel filtration analyses of pronase-treated, trypsin-sensitive, surface fucopeptides indicated a reduction in the average size of the fucopeptides from both dGlc-grown NRK and NRK[MSV-MLV] cells. When the cells were grown in control medium the fucopeptides from the NRK[MSV-MLV] cells were larger than those from NRK cells, i.e. the fucopeptide difference observed in a wide range of transformed versus normal cells. The changes in the fucopeptides of dGlc-grown cells were greater for the NRK cells so that after growth in dGlc-supplemented medium there was an enhancement in the typical fucopeptide differences between normal and transformed cells, namely a larger difference in both size distribution and degree of sialylation. These dGlc-related alterations were readily reversed when the cells were transferred to control medium. The changes in glycosylation were compatible with continued cell replication although there was an increase in doubling time of the dGlc-grown cells, 6-7 h increase for NRK cells, 1-2 h increase for NRK[MSV-MLV] cells.
...
PMID:Differential effects of 2-deoxy-D-glucose on surface glycoproteins of normal and transformed cells. 630 66

The cell membrane receptor for epidermal growth factor (EGF) appears to be a glycoprotein of Mr 170,000 and mediates the mitogenic and metabolic responses of cells with EGF receptors (EGF-R). Normal rat kidney (NRK) have about 3 X 10(5) EGF-R per cell. Upon transformation of NRK cells by Kirsten sarcoma virus, the transformed derivative (KNRK) loses the ability to bind 125I-EGF. Membranes from NRK and KNRK cells were included in EGF-dependent phosphorylation reactions to search for evidence of the EGF-R. A phosphorylated protein of Mr 170,000 was detected in both NRK and KNRK membranes. The Mr 170,000 protein was identified to be EGF-R by immunoprecipitation with monoclonal antibody to the receptor. Furthermore, two-dimensional peptide mapping using trypsin and chymotrypsin digestions of the iodinated receptors from both NRK and KNRK cells showed essentially identical patterns. These data indicate that the EGF-R is present in KNRK cells with apparently the same protein structure as the NRK counterpart.
...
PMID:Nonfunctional epidermal growth factor receptor in cells transformed by Kirsten sarcoma virus. 632 50

Proteolytic digestion of the transforming protein of Rous sarcoma virus (pp60src) with trypsin, chymotrypsin, or thermolysin generated a 29,000-dalton fragment representing the carboxyl half of this molecule. This proteolytic fragment was able to phosphorylate pp60src-specific immunoglobulin as well as exogenous substrates such as angiotensin, casein, and tubulin. When quantitated on a molar basis, the protease-resistant fragment of pp60src had a greater specific activity than the intact enzyme. Digestion of pp90yes, the transforming protein of Y73 sarcoma virus with these proteases yielded a peptide of similar molecular weight which was capable of autophosphorylation as well as the phosphorylation of exogenous substrates. The proteolytic fragments of both pp60src and pp90yes displayed the same strict specificity for phosphorylation of tyrosine as the intact enzymes. These results indicate that the 29,000-dalton carboxyl end of pp60src and pp90yes can function independently as phosphotransferases and indicate that the catalytic domains of these molecules have a conformation which confers protection against limited conditions of proteolysis.
...
PMID:Analysis of the catalytic domain of phosphotransferase activity of two avian sarcoma virus-transforming proteins. 632 78

A serine proteinase was isolated from Walker-256-carcino-sarcoma plasma-membrane-enriched preparations by affinity chromatography employing soya-bean trypsin inhibitor as the ligand. This enzyme was termed 'memsin' owing to its membrane location and trypsin-like substrate specificity. Analysis of this preparation by steric-exclusion high-pressure liquid chromatography (h.p.l.c.) resulted in a single peak of enzyme activity. Calculations of the rates of inactivation of memsin by peptidyl-chloromethanes and comparison with rate constants obtained with other serine proteinases indicated that memsin closely resembled trypsin and acrosin. Digestion of oxidized ribonuclease by memsin and analysis of the resulting peptides by h.p.l.c. yielded a chromatogram that was very similar to one generated by a tryptic digest of oxidized ribonuclease. This enzyme could possibly play a role in tumour-cell invasion.
...
PMID:Isolation and characterization of a trypsin-like serine proteinase from the membranes of Walker 256 carcino-sarcoma cells. 634 14

A method to isolate and maintain microvascular endothelial cells from the cutaneous vessels of adult human skin in long-term culture has been developed. Endothelial cells lining the microvessels of the papillary dermis are released from surrounding tissue during a brief trypsin incubation (0.3% trypsin, 1% EDTA). Cells are plated onto a fibronectin substrate and maintained in Leibovitz (L15) culture medium containing pooled human serum (50%) and antibiotics. Proliferation is dependent upon the presence of several additional growth factors, cholera enterotoxin (1 X 10(-9) M), isobutyl methylxanthine (3.3 X 10(-5) M), and medium conditioned by explant culture of the mouse EHS sarcoma. Using this supplemented medium, cells proliferate readily and can be cultivated serially for more than 6 passages (3 months in vitro). These cells retain their characteristic endothelial cell morphology, stain positively for Factor VIII antigen, and contain Weibel-Palade bodies.
...
PMID:Isolation and long-term serial cultivation of endothelial cells from the microvessels of the adult human dermis. 642 Mar 32

Cancer-associated galactosyltransferase acceptor (CAGA glycoprotein), a small glycoprotein purified from human malignant effusion that selectively kills transformed cells, was tritiated by reductive methylation in the presence of NaB(3)H(4). CAGA-glycoprotein-sensitive cells (baby-hamster kidney cells transformed by polyoma virus and chick-embryo fibroblasts infected with Ts68 temperature-sensitive mutant of Rous sarcoma virus grown at 37 degrees C, the permissive temperature) bound 3-5-fold more (3)H-labelled CAGA glycoprotein than did their CAGA-glycoprotein-resistant non-transformed counterparts. The Rous-sarcoma-virus-infected chick-embryo fibroblasts grown at non-permissive temperature (41 degrees C) bound an intermediate amount of (3)H-labelled CAGA glycoprotein; however, this intermediate amount appeared to be sufficient to induce inhibition of cell growth when the infected chick-embryo fibroblasts treated at 41 degrees C were switched to 37 degrees C. Binding of (3)H-labelled CAGA glycoprotein was time- and temperature-dependent and was not inhibited by monosaccharide. Binding was completely inhibited by the oligosaccharide liberated by endoglucosaminidase H treatment or by exhaustive Pronase digestion of intact CAGA glycoprotein. However, the isolated oligosaccharide failed to demonstrate the growth-inhibition characteristics of the intact glycopeptide. Binding of (3)H-labelled CAGA glycoprotein was unaffected by co-incubation with the peptide core released by endoglucosaminidase H treatment. (3)H-labelled CAGA glycoprotein bound to intact cells could be removed by trypsin treatment up to 4h after addition of the glycoprotein but not thereafter. This time course paralleled the decreasing reversibility of growth inhibition. However, all (3)H-labelled CAGA glycoprotein was found in the supernatant when cells were first disrupted by sonication followed by trypsin treatment for up to 12h. (3)H-labelled CAGA glycoprotein linked to Sepharose 4B failed to cause growth inhibition in CAGA-glycoprotein-sensitive cells. These findings suggest that binding of CAGA glycoprotein occurs via its oligosaccharide moiety. Binding appears to be a necessary but not sufficient condition to induce cell killing. Growth inhibition appears to depend on internalization of the glycoprotein and the presence of a transformation-specific cell process.
...
PMID:Transformation-specific cell killing by a cancer-associated galactosyltransferase acceptor and cellular binding. 681 50

Certain metabolic properties of hormonally responsive osteogenic sarcoma cells derived from a transplantable rat tumor have been compared with those of related normal rat bone cells. All studies were carried out on cells grown in monolayer culture. Normal rat bone cells derived by repeated collagenase/trypsin digestion of newborn rat calvaria. Bone cells selected for comparison were thought to be osteoblast-like, as judged by enrichment of alkaline phosphatase and adenylate cyclase responsiveness to parathyroid hormone and prostaglandin E2. The adenylate cyclases of the two cell strains were similarly stimulated by a range of prostanoids and their metabolites and analogs. Morphology showed the two cell strains to be similar; the only obvious difference was a multilayering of cells in the sarcoma cultures, while the normal cultures showed abundant extracellular fibril formation which was not seen in the tumor cells. Investigation of the cAMP-dependent protein kinase isoenzymes showed the presence of two forms in both cell types, one eluting at a low salt concentration and the other at a high salt concentration. There was approximately twice the amount of the first isoenzyme compared to the second isoenzyme. The results indicate the usefulness of the two cell strains to elucidate further the molecular mechanisms of action of parathyroid hormone and prostaglandins.
...
PMID:Functional properties of hormonally responsive cultured normal and malignant rat osteoblastic cells. 693 60

A tumor antigen associated wtih canine transmissible venereal sarcoma (CTVS) has been identified and partially characterized. The antigen was demonstrated in 3-M KCI and saline extracts of washed CTVS cells. Rabbit anti-CTVS antisera absorbed wih glutaraldehyde cross-linked normal dog serum and pooled homogenates of canine spleen, thymus, lymph node, and liver were used to identify the antigen. The specificity of the rabbit anti-CTVS antiserum for the CTVS antigen was established by use of immunodiffusion, two-dimensional electrophoresis, and the enzyme-linked immunosorbent assay (ELISA). Extracted CTVS antigen was fractionated by Sephadex G-200 chromatography, and the antigen factions were identified with the use of absorbed rabbit anti-CTVS antiserum and the ELISA technique. Antigen activity was detected in samples with estimated molecular weights greater than 70,000 daltons. Antigen fractions reacted with absorbed anit-CTVS antiserum to form a single precipitation band in immunodiffusion studies. Extraction of CTVS antigen with 3 M KCl and saline in the presence of a protease inhibitor did not significantly alter the antigen activity or molecular weight of the CVTS antigen. Cytoplasmic and nucleolar fluorescence were observed in an indirect immunofluorescence test with the use of acetone-fixed CTVS cells and absorbed anti-CTVS antiserum. The CTVs antigen activity was greatly reduced by trypsin digestion, by incubation for 1 hour at 65 degrees C, and by exposure to pH 2.8, 4.0, and 11.0 for 1 hour each.
...
PMID:Identification and physicochemical characterization of a tumor-associated antigen from canine transmissible venereal sarcoma. 693 24

One case of a very rare myosarcoma of ovarium origin was observed and establishment of its cell lines from the fluid obtained by paracentitis was accomplished. This report is on the determination of the tumor and the biological characteristics of its cultured cells. (Determination of the tumor) (1) This tumor was diagnosed as a malignant of the right ovary, using bimanual examination, selective angiography of the uterine artery, ultrasonic tomography, and abdominal ascitic cell examination. (2) The morphological type of tumor was based findings of hematoxylin eosin. Silver, Mallory and phosphotungstic acid hematoxylin stainings. The tumor was diagnosed as an ovarian sarcoma and probably myogenic. However, a clear cross strain could not be demonstrated. (Cell biological characteristics) (1) Morphological characteristics of cultured cells: a) Phase-contrast microscopy and Papanicolaou staining revealed round or short and spindle shaped cells, with markedly enlarged nucleoli. These proliferated without exhibiting any tendency of contact inhibition. Also frequently recognized were giant cells, multinuclear cells, an some bizarre such as a starfish-shaped cell. b) Electron microscopy revealed that bundles of fibrils regarded as myofibrils existed in the cytoplasma, with dense patches within them, but a cross strain could not be demonstrated. (2) Morphological characteristics of the tumor cells grown in a nude mouse: a) The tumor cells demonstrated similarities to the original tissues by of H.E., Silver, and Mallary stainings. b) A number of fibrils recognized by the electron microscopic observation were 100 A in width and were arranged in a concentric circles. In addition to the light microscopic findings, the above findings indicated that this cell line originated from myogenic sarcoma. (3) Biological characteristics of the cultured cells: a) The number of chromosomes varied widely and spread aneuploidically, the highest chromosome number was 76. b) Doubling time, Saturation density, and plating efficiency was 31.2 hr, 1.2 x 10(5)/cm2 and 43.9% respectively. c) These cells had a high sensitivity for trypsin and started morphological change rapidly.
...
PMID:[Human ovarian myosarcoma and its cell culture (author's transl)]. 703 11


<< Previous 1 2 3 4 5 6 7 8 Next >>

---