Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.4 (trypsin)
 42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Several human granulocyte proteinases sensitive to the thermo- and acid-resistant proteinase inhibitor from rabbit serum (TASPI) were revealed, using TASPI-Sepharose 4B. It was found that TASPI inhibits the following human granulocyte proteinases: granules-localized kininogenase and chymotrypsin-like kininase (serine proteinases), elastase-like proteinase and benzoyl arginine ethyl ester esterase, as well as chymotrypsin-like kininase from the post-granule supernatant. These enzymes were compared to known granulocyte proteinases. Some carboxylic kininogenase sensitive to TASPI was identified in the granulocyte membrane debris fraction. The capability to inhibit neutral kininogenase suggests that TASPI is a first natural proteinase inhibitor, which can differentiate granulocyte and blood plasma kininogenases. Using trypsin-Sepharose 4B in the granulocyte post-granule supernatant, the acid-resistant trypsin and chymotrypsin inhibitor was identified. The data obtained are indicative of an antiinflammatory function of TASPI in mammals.
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PMID:[Inhibition of human granulocyte proteinases by a heat and acid-stable proteinase inhibitor from rabbit serum]. 43 77

Neutral proteoglycanase and other protease activity from cellular and CM fractions of monolayer-cultured rabbit articular chondrocytes were studied. The cellular fraction comprising soluble cytoplasmic enzymes possessed concentration-dependent elastase-like esterase activity and activity against trypsin and chymotrypsin synthetic substrates but had little caseinase activity. The 20% ammonium sulfate precipitate of CM possessed more neutral caseinase activity than the 60% ammonium sulfate precipitate and the bulk of activity against the synthetic substrates. Activity against bovine nasal septum PG was present in these fractions. Both the 20% and 60% ammonium sulfate fractions reduced the viscosity and the S of the PG substrate. This activity was incompletely inhibited by preincubation with either 5 mM o-phenanthroline or 10 mM EDTA, indicating that it was paritally metal-dependent. The activity in the cellular fraction was also partially inhibited by o-phenanthroline but more so by EDTA. These data indicate that chondrocytes synthesize and secrete into the culture medium neutral proteoglycanase(s) capable of initiating degradation of PG derived from the neutral pH cartilage matrix. The inhibitory profiles, together with recent evidence of enzymes with similar activity extracted from cartilage suggested that the proteoglycanase enzyme(s) may occur in multiple forms.
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PMID:Metal-dependent neutral proteoglycanase activity from monolayer-cultured lapine articular chondrocytes. 43 3

Cell-surface markers were investigated in 7 patients with giant-cell tumours and 30 patients with other tumours as controls. 25--55% of mononuclear cells in giant-cell tumours showed immunoglobulin-mediated phagocytosis. These phagocytic cells showed rapid adherence, trypsin resistance and potent nonspecific esterase activity. Thus, giant-cell tumours contained considerable numbers of macrophages with typical characteristics and functions. Macrophages did not proliferate in cultures of giant-cell tumours, whereas the non-adherent cells did. Further, established cell lines from these tumours consisted of spindle-shaped cells without surface markers or the ability to phagocytose or display nonspecific esterase activity. We consider that macrophages, which may be precursors of giant cells in giant-cell tumours, are non-malignant cells of host origin rather than tumour cells acquiring some properties of macrophages. We found that macrophages were more abundant in giant-cell tumours than in other tumours of mesenchymal origin, but any effect of their presence on the clinical behaviour and prognosis of the tumour remains highly speculative.
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PMID:Giant-cell tumour of bone: cytological studies. 47 66

The ability of lymphocytes to lyse human red cells coated with anti-D antibody was assessed by measuring 51 Cr release from labeled red cells incubated with peripheral blood leukocyte suspensions from 12 normal donors. Mixed mononuclear cell suspensions (containing monocytes and lymphocytes) from all donors produced lysis of sensitized red cells. Treatment with carbonyl iron reduced monocyte concentration to less than 1.2% in all donors, as measured by morphologic criteria, esterase staining and ingestion of latex particles. Lysis of red cells following monocyte depletion was markedly reduced in 8 of the 12 donors. Despite depletion of monocytes, unchanged or increased lysis was noticed with the leukocytes of the remaining 4 donors. This lysis was due to lymphocytes, not to residual monocytes. If target red cells were treated with papain or trypsin prior to sensitization, marked lysis occurred with lymphocytes of all donors, including those which did not lyse unmodified red cells. Direct cytolysis of sensitized red cells during contact with small lymphocytes was recorded using microcinematography, which confirmed the role of lymphocytes in mediating lysis. Lymphocyte-mediated lysis of red cells increased with mounting levels of antibody sensitization regardless to prior treatment with papain. Papain increased antibody coating per red cell, yet lysis per molecule of antibody bound was also increased. Lysis was inhibited by IgG1 and IgG3 in the fluid phase but not by IgG2 or IgG4. At an equivalent level of antibody sensitization lysis was augmented by concurrent coating of the red cells with C3b, C3d and/or C4b, though these components could not produce lysis in the absence of antibody coating.
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PMID:Quantitative evaluation of antibody-dependent lymphocyte-mediated lysis of human red cells. 53 2

The reversible inhibition of the enzymatic activity of trypsin by heparin was investigated. On the basis of an analysis of the Lineweaver-Burk and Dixon graphs, a noncompetitive nature of the inhibition of the BAPA amidase activity of trypsin by heparin was detected, and the values of Km and Ki were determined, equal to 3.1 . 10(-4) and 3.7-3.9 . 10(-7) M, respectively. A comparison of these values indicates a great affinity of heparin for the enzyme. It was shown that heparin inhibits the BAEE esterase activity of trypsin and at the same time has no inhibiting effect on acetyltrypsin. Considering that the acetylation of trypsin leads to selective blocking of the epsilon-amino groups, it was concluded that the epsilon-amino groups of the lysine residues of the trypsin molecule participate in the interaction with heparin.
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PMID:Investigation of the interaction of trypsin with heparin. 54 62

By combining velocity and linear density fractionations as well as target cell rosetting techniques we have isolated and morphologically identified the human effector cell type responsible for spontaneous, trypsin-augmentable cytotoxicity against chicken red cells and human myeloma cell line targets. This cell is a large lymphoid cell with strong alpha-naphthyl esterase activity concentrated in a limited area in the cytoplasm usually at the indentation site of a slightly reniform nucleus. Cells with this morphology also formed plaques on chicken erythrocyte monolayers. The cell is nonphagocytic and nonadherent, it carries Fc receptors but no complement receptors on its surface, and shows a weak affinity to sheep red blood cells (SRBC). The frequency of these cells based on morphological analysis is 3 x 10(4)--6 x 10(4)/ml in normal human blood. This cell shows similarities (surface Ig-, Fc+, C3-) with the human natural killer (NK) cells lytic to hematopoetic target cell lines but differs in that the cytotoxicity is augmentable by trypsin and the affinity to SRBC is lower. Therefore, we postulate that these two killer populations represent different subpopulations of human NK cells.
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PMID:Identification of the effector cells in human blood displaying spontaneous cytotoxicity to chicken erythrocytes. 59 Mar 20

The syntheses are described of p-guanidino-L-phenylalanine and some of its derivatives. alpha-N-(p-Toluenesulphonyl)-p-guanidino-L-phenylalanine methyl ester is an excellent substrate of bovine trypsin (EC 3.4.21.4) (Km 57 micron; kcat. 320s-1 at pH 7.4-8.0) and a very poor substrate of human thrombin (EC 3.4.21.5) (Km 190 micron, kcat. 0.2s-1) and bovine chymotrypsin (EC 3.4.21.1). The ester inhibits thrombin clotting activity. It also inhibits the amidase and esterase activities of human thrombin, this inhibition being of the mixed type. The inhibition constant, K1, of the order of 1 micron, increases with increasing inhibitor concentration. This suggests that the enzyme binds the inhibitor at multiple sites. The importance of the residue at the P1 position [notation of Berger & Schechter (1970) Philos. Trans. R. Soc. London Ser. B 257, 249-264] in determining the selectivity of a substrate or quasi-substrate among trypsin-like enzymes is borne out. p-Guanidino-L-phenylalanine may have a use in the synthesis of selective peptide inhibitors of thrombin.
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PMID:The interaction of alpha-N-(p-toluenesulphonyl)-p-guanidino-L-phenylalanine methyl ester with thrombin and trypsin. 62 42

18-25-fold purified alpha-thrombin, having high esterase activity and coagulating ability of 2500 NIH u per 1 mg of protein, was isolated using chromatography of commercial thrombin through SP-Sephadex C-50. Limited proteolysis of alpha-thrombin on the column with immobilized trypsin resulted in the appearance of beta-thrombin with alpha-thrombin-like esterase activity and tracing coagulating activity (2-5 NIH u per 1 mg of protein). Molecular weight analysis of alpha- and beta-thrombin forms suggests that a peptide (or peptides) with Mr of 1100 is splitted off under proteolysis. Some similarity is revealed in kinetic parameters (Km(app) and kkat) of TAME and BAME hydrolysis by alpha- and beta-thrombin, although Km(app) is somewhat low (approximately 2-fold) for alpha-thrombin. Investigation of TAME hydrolysis kinetics by both thrombin forms at a wide range of substrate concentrations has revealed the effect of substrate activation. Kinetic constants Ks and beta for high substrate concentrations are calculated. It is suggested that the similarity of alpha- and beta-thrombin action on arginine esters and sharp differences in their effect on fibrinogen may be a result of a disturbance of substrate-binding region of beta-thrombin active site.
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PMID:[Comparison of the catalytic properties of alpha- and beta-forms of thrombin]. 65 98

Psoriatic scale extracts were fractioned by using polyacrylamide gel isoelectric focusing (PAGIF) and preparative electrofocusing in granulated gel (PEGG). The largest protein fraction was found with Ip at pH 4.8--5.0, and the main protein bands within pH values 4.0--7.5. PEGG separated three main fractions with plasminogen activator or trypsin-like esterase activity with isoelectric points at pH 6.5--6.6, 5.4--6.2 and 4.9. The enzyme with Ip at pH 6.5--6.6 hydrolyzed trypsin substrates but lacked plasminogen activator capacity. The enzyme with Ip at pH 5.4--6.2 showed both activities but the third enzyme with plasminogen activator capacity with Ip at pH 4.9 was without detectable esterolytic activity towards substituted basic amino acid esters. The third enzyme was prominent in KCl-extract and the second in KSCN-extract. The first was equal in both extracts. The enzyme with Ip at pH 4.9 is possibly of bacterial origin while the plasminogen activator with Ip at pH 5.4--6.2 extracted in KSCN probably represents tissue activator of psoriatic scales.
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PMID:Plasminogen activators of psoriatic scale extracts. Separation of two plasminogen activators by isoelectric focusing. 68 9

Five giant cell tumours of bone were studied to determine the degree of macrophage infiltration and whether the giant cells expressed the characteristics commonly associated with macrophages, i.e., IgGFc and C3 receptors, phagocytosis and non-specific esterase activity. Macrophages were assessed in trypsin-derived tumour cell suspensions by IgGEAC rosette formation and in frozen sections of tumour by EA adsorption. The percentage of macrophages in cell suspensions from four of the tumours ranged from 11 to 40 per cent. Strong EA adsorption occurred over 35 to 95 per cent. of the tumours' surface and significant non-specific esterase positivity was observed in the tumour sections. The giant cells were receptor negative and non-phagocytic, but a low percentage of them expressed esterase activity. The results strongly suggest that despite the fact that large numbers of macrophages were present in the tumours, the giant cells were derived from cells other than macrophages.
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PMID:Macrophages in giant cell tumours of bone. 72 90


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