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)

The neoantigenic determinants (neoAg) which have been identified in the human C5b-9 membranolytic C complex were detected here by the direct fluorescent antibody technique on the surface of 27 +/- 11% of viable peripheral blood leukocytes (PBL). The cells were prepared from defibrinated blood by sedimentation on Ficoll-Hypaque. Specificity of the antisera was established by quantitative inhibition of the fluorescent staining reaction, and of agglutination of EAC1-7, by highly purified C5b-9 complex. No inhibition was observed with fresh normal human serum. The majority of the PBL with surface neoAg was found in the B lymphocyte subpopulation that failed to form rosettes with sheep erythrocytes. NeoAg on B lymphocytes was removed to differing degrees by trypsin, papain, or pepsin treatment, and by maintaining the cells at 4 degree C for 20 hr in serum-free medium. The individual components, C5, C6, C7, C8, and C9, were also detected on the surface of PBL. With differential fluorescent stains, C5 and neoAg as well as C8 and neoAg could be detected on the same cells. The results indicate that viable B lymphocytes prepared from defibrinated blood, have the components of the membrane attack complex of C on their surface. The concomitant occurrence of the neoAg indicates that these proteins are present at least in part in the form of the assembled terminal complex.
...
PMID:Leukocyte complement: neoantigens of the membrane attack complex on the surface of human leukocytes prepared from defibrinated blood. 7 29

To characterize the initial step in alveolar macrophage (AM)-lymphocyte (L) interaction in the human lung, we studied the ability of human AM to bind autologous blood L in vitro in the absence of antigen. AM were obtained by saline bronchial lavage through a fiberoptic bronchoscope. Monolayers of AM attached to glass bound autologous blood L prepared by Ficoll-Hypaque and nylon wool column separation. The AM-L binding increased from zero time to a maximum at 2 h and then declined to a zero time value at 18 h. The binding was dependent on the number of L added to the AM monolayers, with greatest binding at an AM:L ratio of 1:50. AM:L binding required viability of AM, but not of L, and was temperature dependent. Pretreatment of AM with iodoacetic acid, trypsin, neuraminidase, or colchicine diminished attachment of L at 2 h. Neuraminidase pretreatment of L resulted in increased binding to nontreated AM. Thus, a physical interaction between human AM and autologous peripheral blood L can occur in vitro in the absence of known antigen; similar interaction in vivo may play a role in the generation of cell-mediated immune responses in the lung.
...
PMID:Human alveolar macrophages: antigen-independent binding of lymphocytes. 36 39

The elaboration of leukocyte chemotactic factors by human fibroblasts was studied. 12 lines of normal fibroblasts obtained by skin biopsy and then cultured in vitro produced chemoattractants (assessed by modified Boyden-chamber techniques) for both peripheral blood polymorphonuclear leukocytes and monocytes (obtained by Hypaque-Ficoll and dextran sedimentation). Chemotactic activity was not present performed in fibroblasts, and cycloheximide blocked its elaboration. The chemotactic activity of crude-culture supernate was heat stable (56 degrees C for 30 min), trypsin- and pronase-sensitive, and neuraminidase resistant. Characterization of the chemotactic activity by gel filtration (Sephadex G-75) showed two active fractions, one with mol wt greater than 100,000 and the other less than 10,000. In studies designed to relate these chemotactic factors to collagen, we have confirmed that type I collagen and alpha 1-chain; are chemotactically active for monocytes but not polymorphonuclear leukocytes. However, the chemotactic activity in fibroblast-culture media was media was distinct from collagen in that it attracted neutrophils, it was not precipitated by 25% ammonium sulfate, and it was resistant to collagenase treatment; ascorbic acid, in concentrations known to stimulate fibroblast collagen synthesis, had no effect on the elaboration of the chemotactic factors. Furthermore, amino acid analysis of Sephadex G-75 fractions with chemotactic activity failed to reveal amino acids such as hydroxyproline characteristic of collagen. In addition to the chemotactic factors secreted by fibroblasts, a heat-resistant factor (30 min at 56 degrees C) which generated the chemotactically active fragment of C5 (C5a) from human serum was also secreted. The elaboration of mediators of the inflammatory and immune responses by fibroblasts may initiate and(or) modulate local skin inflammatory reactions and play a protective role in vivo.
...
PMID:Polymorphonuclear leukocyte and monocyte chemoattractants produced by human fibroblasts. 43 25

The peritoneal cavity of guinea pigs proved to be a rich source of mononuclear cells (34-52%) with fibrinogen or fibrin (Fib) on their surface. The Fib was readily detected on the surface of viable cells in suspension by fluorescence microscopy using antisera to guinea pig fibrinogen. The fluorescent staining occurred either in a speckled distribution, similar to that of cytophilic IgG, or in a distinctive net-like pattern that probably represented fibrin formation on the cell surface. The binding of Fib to the cell surface required calcium, but not magnesium, in the medium and could occur in vitro during incubation in heparinized plasma that contained fibrinogen concentrations comparable to that in normal peritoneal fluid (0.58 mg/ml). Cell surface Fib was more susceptible to plasmin and trypsin digestion than surface cytophilic IgG. By morphologic and physiologic criteria, cells exhibiting surface Fib were chiefly, if not exclusively, macrophages. Granulocytes, erythrocytes, and lymphocytes from lymph node and thymus had no sppreciable Fib. Cells with surface Fib were rarely observed among mononuclear cells prepared by Ficoll-Hypaque sedimentation of guinea pig and human blood (1.4 and 4.6%, respectively). Pulmonary alveolar macrophages, functionally distinct from peritoneal macrophages, lacked surface Fib (0.8%). Polymerization of Fib on the surface of macrophages might participate in certain cell interactions, such as the adherence of peritoneal macrophages during the antigen-induced macrophage disappearance reactions. The unexpected finding of Fib binding to the surfaces of peritoneal macrophages raises the possibility of a biologically significant interaction between these cells and the clotting system.
...
PMID:Fibrinogen/fibrin on the surface of macrophages: detection, distribution, binding requirements, and possible role in macrophage adherence phenomena. 110 45

In an attempt to clarify a mechanism of polymorphonuclear cell and/or macrophage infiltration in alcoholic liver disease, we investigated a novel chemotactic and activating factor generated by rat hepatocytes isolated from the chronically ethanol-fed rats. Hepatocytes and hepatic macrophages were isolated from rat liver by perfusion and digestion with collagenase and subsequently by differential centrifugation on a metrizamide gradient. Rat polymorphonuclear cells were prepared from blood by the dextran sedimentation and Hypaque-Ficoll technique. Chemotactic activity was measured as migration of polymorphonuclear cells or hepatic macrophages using a chemotactic chamber. When hepatocytes isolated from the ethanol-fed rats were cultured in vitro, chemotactic activity for rat polymorphonuclear cells and hepatic macrophages was demonstrated in the culture supernatant. Inhibitors of transcription and protein synthesis reduced generation of chemotactic factor from these hepatocytes. Chemotactic activity of the conditioned medium was reduced after trypsin (0.25%, 37 degrees C, 30 min) or heat (56 degrees C, 30 min) treatment. The chemotactic activity was eluted at molecular weights of 20-25 kDa and 40-45 kDa following Sephadex G-150 chromatography. Superoxide anion production by polymorphonuclear cells and hepatic macrophages under the stimulation of phorbolmyristate acetate was enhanced in the presence of this chemotactic factor. This chemotactic factor may contribute to the pathogenesis of alcoholic liver disease.
...
PMID:Generation of chemotactic factor by hepatocytes isolated from chronically ethanol-fed rats. 156 5

The production of interleukin (IL 1) by normal human peripheral blood monocytes purified by Ficoll-Hypaque density sedimentation, Percoll-gradient sedimentation, and plastic adherence can be detected as early as 30 min intracellularly, and extracellularly within 1 hr after stimulation with lipopolysaccharide (LPS). Production of mRNA coding for the isoelectric point 7.0 species of IL 1 was also detected as early as 1 hr after LPS stimulation and reached a maximum level at 6 hr. Cell-associated IL 1 activity could be extracted with CHAPS detergent from every cell fraction (i.e., membranes, cytosol, and particulates), but was present mainly (greater than 95%) in the cytosol of LPS-activated monocytes and the myelomonocytic cell line, THP-1. The apparent m.w. of IL 1 activity on high pressure liquid chromatography gel filtration in every cell fraction was approximately 23,000 daltons, with a minor peak at 31,000 daltons, whereas the IL 1 activity in the culture supernatants was 17,000 daltons. Western blotting analysis of LPS-stimulated monocyte extracts showed two forms of IL 1 corresponding to 31,000 daltons and 25,000 daltons. Exposure of viable cells to trypsin and plasmin released biologically active 23,000 dalton IL 1 only from IL 1-producing cells such as activated monocytes and IL 1-producing Ebstein-Barr virus B lymphocyte cell lines. Consequently, biologically active IL 1 is presumably exposed on the outer surface of cell membranes. Furthermore, IL 1 release by human monocytes in plasminogen-depleted fetal calf serum was considerably decreased. Conversely, supplementation of plasminogen-depleted serum with purified plasminogen restored the IL 1 production, suggesting that plasmin or plasmin-like factors may be involved in the regulation of the release of IL 1 from IL 1-producing cells. In conclusion, the results suggest that IL 1 is rapidly produced, is pooled in the cytosol, and in part is processed by enzymes, is transferred to the plasma membranes, and is then released from the cells. Tissue plasminogen activator and serum enzymes such as plasmin may therefore be involved in the release of IL 1 from IL 1-producing cells.
...
PMID:Intracellular localization of human monocyte associated interleukin 1 (IL 1) activity and release of biologically active IL 1 from monocytes by trypsin and plasmin. 242 Aug 74

The T-cell surface differentiation antigens expressed on cortical thymocytes are composed of 3 molecules, CD1a (Mr 49,000), CD1b (Mr 45,000), and CD1c (Mr 43,000), which are non-covalently attached to beta 2-microglobulin. In the present study, differences in quantitative binding (immunogold labelling) were observed with four CD1a monoclonal antibodies (mAb), Na1/34, L544, Vit6 and OKT6, on epidermal Langerhans cells obtained through trypsinization and Ficoll-Hypaque sedimentation. These cells were surface-labelled with 125I and then lysed. Immunoprecipitation was carried out with five CD1a mAb, BL6, 10D12.2, L404, L544 and OKT6, and immunoprecipitates were electrophoretically run. All CD1a mAb except OKT6 immunoprecipitated an additional molecule with an apparent relative mass of 27,000, under reducing conditions. CD1a antigen (Mr 49,000) was borne by the same chain of Mr 49,000 on cortical thymocytes and Langerhans cells, whereas the Mr 27,000 molecule was never found on thymic cells. On two-dimensional gel analysis, the Mr 27,000 molecule showed a pattern with 3 major spots with pI of 5.6, 5.9 and 6.2. This Mr 27,000 protein was found to contain one N-linked oligosaccharide residue by endoglycosidase-F treatment. By sequential immunoprecipitation, this Mr 27,000 molecule was shown to be different from the major histocompatibility complex class II beta-chains (DR, DP). As the Mr 27,000 molecule was not precipitated with OKT6, sequential immunoprecipitation confirmed specific recognition of this low molecular weight protein by other CD1a mAb. The protein of apparent molecular mass 27,000 was considered to be a breakdown product of Mr 49,000 (CD1a) antigen. These results suggested that the CD1a molecule was sensitive to trypsin.
...
PMID:Cleavage of Langerhans cell surface CD1a molecule by trypsin. 247 41

We have been interested in contributions of certain cells and mediators to synovial inflammation rheumatoid arthritis (RA). The present studies were designed to determine (1) whether monocytes contained the neutral proteinase cathepsin G and (2) if neutral proteinase could induce or potentiate cellular IgM rheumatoid factor (RF) production. Monocyte-rich and monocyte-poor populations were isolated by Ficoll-Hypaque density sedimentation followed by glass adherence, and cellular lysates were obtained by repetitive freezing and thawing as we have reported for neutrophil-derived neutral proteinase. Cathepsin G was quantified immunochemically by an enzyme-linked immunoassay (ELISA) we developed utilizing commercially available anti-cathepsin G antibodies. Mononuclear and B-cell-enriched cell cultures were prepared by standard methods and IgM RF measured by our ELISA. Cell-derived lysates from monocyte-enriched populations (84 +/- 3% monocytes, less than 1% neutrophils) contained considerably greater amounts of measurable cathepsin G (OD280 = 0.393 +/- 0.153) than lysates from equal numbers of monocyte (15 +/- 2% monocytes, less than 1% neutrophils)-depleted cells (OD280 = 0.071 +/- 0.038; P less than 0.05). Eighteen patients with RA and three normal individuals did not have consistently increased cellular elaboration of Ig or IgM RF in vitro in response to proteinase (trypsin) stimulation; however, patients manifested 80% potentiation by trypsin of pokeweed-stimulated cellular IgM RF production in vitro (pokeweed-stimulated IgM RF 137 +/- 53 ng/ml, pokeweed/trypsin-induced IgM RF 246 +/- 100 ng/ml; P less than 0.02), changes being most striking for those patients seropositive by latex fixation test (84% increase, P less than 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Human mononuclear cells and neutral proteinases. III. Neutral proteinases and rheumatoid arthritis: monocytes as a source of cathepsin G and proteinase potentiation of IgM rheumatoid factor elaboration. 275 24

Discrepancies in correlations between fibrinolytic activity and metastatic potential of malignant cells has resulted in speculation on the putative role of plasminogen activators (PA) in cancer. In this report we have compared lymphocyte PA from 40 patients with chronic lymphocytic leukemia (CLL) to normal human B- and T-lymphocytes. Lymphocytes were isolated from peripheral blood by Ficoll-Hypaque centrifugation. The B- and T-cells were further separated on nylon wool columns. Cell PA activity and cell membrane PA were determined using 3H-fibrin-coated plates with added human plasminogen. Lymphocytes did not lyse 3H-fibrin in the absence of plasminogen. Plasminogen-dependent fibrinolytic activities of normal B- and T-lymphocytes were comparable. The addition of protease inhibitors with trypsin or plasmin specificity to lymphocytes significantly inhibited normal PA, thus substantiating the serine protease spectrum of lymphocyte PA. Examination of lymphocytes from greater than 95% of patients with chronic lymphocytic leukemia revealed a marked decrease in lymphocyte and cell membrane PA as compared to normals. No correlation between Stage of CLL and lymphocyte PA was observed. Likewise, an inhibitor of PA in CLL lymphocytes was not detected. The function of PA in normal B-lymphocyte physiology and the potential pathogenetic role of diminished PA in CLL lymphocytes remain to be explored.
...
PMID:Plasminogen-dependent fibrinolytic activity in normal human lymphocytes: diminished lymphocyte plasminogen activator in chronic lymphocytic leukemia. 392 13

Small quantities of Gastrografin remaining in the intestinal tract some hours after introduction have been shown to cause falsely low trypsin values as determined by a spectrophotometric assay system. This interference is due first to the high absorbance of Gastrografin at 254 nm resulting in a falsely high background optical density. Secondly, Gastrografin inhibits esterase activity towards the synthetic substrate used in this assay. Gastrografin did not interfere with gelatin proteolysis by trypsin and did not affect amylase or lipase determination. Thus the instillation of Gastrografin into the duodenum before pancreatic function tests should be avoided when the trypsin content is to be determined spectrophotometrically.
...
PMID:Interference by Gastrografin with a spectrophotometric trypsin assay. 503 96


1 2 Next >>

---