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)

The clearances of 125I-labeled alpha 1-proteinase inhibitor-trypsin, antithrombin III-thrombin and alpha 2-macroglobulin-methylamine (CH3NH2) were compared in our previously described mouse model. alpha 1-Proteinase inhibitor-trypsin cleared with a t 1/2 of 20 min, antithrombin III-thrombin of 7 min and 125I-labeled alpha 2-macroglobulin-methylamine of 2 min. Competition studies were performed to determine whether one or several pathways clear these three ligands. The clearance of 125I-labeled alpha 1-proteinase inhibitor-trypsin and 125I-labeled antithrombin III-thrombin was blocked by large molar excesses of either ligand, but not by alpha 2-macroglobulin-methylamine. The clearance of 125I-labeled alpha 2-macroglobulin-methylamine can be blocked by a large molar excesses of unlabeled alpha 2-macroglobulin-methylamine but not by alpha 1-proteinase inhibitor-trypsin. These studies demonstrate that the clearance of alpha 1-proteinase inhibitor-trypsin complexes is independent of alpha 2-macroglobulin-methylamine and utilizes the same pathway which is involved in the clearance of antithrombin III-thrombin complexes.
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PMID:In vivo catabolism of alpha 1-proteinase inhibitor-trypsin, antithrombin III-thrombin and alpha 2-macroglobulin-methylamine. 617 38

The regulation of human Factor Xa was studied in vitro in human and mouse plasma, and in vivo in mouse. In human plasma, 125I-Factor Xa bound to alpha 1-proteinase inhibitor, antithrombin III, and alpha 2-macroglobulin in a ratio of 4.9:1.9:1 as determined by gel electrophoresis and by adsorption to IgG-(antiproteinase inhibitor)-Sepharose beads. The distribution of Factor Xa in mouse plasma was similar. The clearance of Factor Xa in mice was rapid (50% clearance in 3 min) and biphasic. alpha 1-Proteinase inhibitor-trypsin, even at a 2,000-fold molar excess, failed to inhibit the clearance of Factor Xa, while alpha 2-macroglobulin-trypsin inhibited only the later phase of clearance. The plasma clearance of diisopropylphosphoryl-Factor Xa was more rapid than native Factor Xa (50% clearance in 2.5 min), and the clearance was blocked by diisopropylphosphoryl-thrombin. Electrophoresis experiments confirmed that by 2 min after injection into the murine circulation, 90% of the bound Factor Xa was on alpha 2-macroglobulin, in marked contrast to the in vitro results. Organ distribution studies at 3 and 15 min with 125I-Factor Xa demonstrated that the majority of radioactivity was in the liver, with significant radioactivity also present in lung and kidney. Autopsies performed 30 s after injection of 125I-Factor Xa also demonstrated significant binding to the aorta and vena cava. These studies indicate that Factor Xa binds to specific thrombin-binding sites on endothelial cells, and that this binding alters its proteinase inhibitor specificity. Factor Xa binds to alpha 2-macroglobulin in vivo, whereas the predominant in vitro inhibitor of Factor Xa is alpha 1-proteinase inhibitor.
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PMID:Regulation of factor Xa in vitro in human and mouse plasma and in vivo in mouse. Role of the endothelium and plasma proteinase inhibitors. 619 77

One of the esteroproteinases present in the submandibular glands of female mice was purified and characterized. The enzyme, designated proteinase F in this report, had a pI value of 4.6 and a molecular weight of 27600, being comprised of two subunits of 10000 and 18000 daltons. The amino acid composition of proteinase F resembled that of the epidermal growth factor-binding protein, but antiserum against proteinase F only reacted weakly against the binding protein. Proteinase F had an optimum pH at around 9.0 and was strongly inhibited by Cu2+ and Hg2+ (42 and 76% inhibition, respectively, at a concentration of 4 x 10(-6) M). It was also inhibited by aprotinin, phenylmethylsulfonylfluoride, iodoacetamide, leupeptin, antipain, and benzamidine but neither by trypsin inhibitors from pancrease, soybean, or ovomucoid, nor by TLCK, TPCK, and epsilon-amino-n-caproic acid. Although its actual physiological function has yet to be determined, these properties indicate that proteinase F is a new enzyme, being distinguished from known proteinases, kallikrein, plasmin, trypsin, chymotrypsin, tonin, angiotensin-converting enzyme, proteinase A (beta-nerve growth factor endopeptidase), proteinase D (epidermal growth factor-binding protein), P-esterase, renin A, and renin C. Proteinase F was present in the submandibular glands of female mice more abundantly than in those of males, but it increased in males following castration. Thus, proteinase F appears to be affected by male hormones in vivo.
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PMID:A new esteroproteinase (proteinase F) from the submandibular glands of female mice. 633 33

Indirect immunofluorescence has been used to examine surface antigens of lizard myogenic cells during in vitro differentiation. At least two developmental stage-specific surface alterations have been identified. One of these is a compositional change and involves the appearance of a cell-surface antigen(s) as the cells differentiate. This antigen(s) (Ag1422) is muscle specific and is characteristic of some rounded-up G0 myosin-positive myocytes, all stretched-back, G0 myosin-positive myocytes, and all identifiable myotubes. The antigen is not found on proliferating myoblasts, extended G1 (myosin-negative) cell-cycle-competent myoblasts or newly differentiated rounded-up, G0 myosin-positive myocytes. Pretreatment of cells with neuraminidase, trypsin, or proteinase K indicates the antigen is not present in "masked" form on normally nonreactive cells. Proteinase K is effective in the removal or destruction of the antigen, indicating it is at least partially protein in nature. The antigen is expressed in a similar developmental stage-specific fashion on early-passage myogenic cells taken from both adult lizard tail regenerates and embryonic muscle. The antibodies identifying Ag1422 can be removed by adsorption with homogenates of mature skeletal muscle. Therefore, Ag1422 is not an artifact due to in vitro conditions or the expression of a transformation antigen unique to the continuous culture line. The second alteration is an apparent restriction in the mobility of surface components (antigens and lectin receptors). Upon treatment with multivalent ligands, undifferentiated myosin-negative myoblasts exhibit rapid patching and capping of cell surface components while well-differentiated myocytes and myotubes do not. This mobility restriction is evident after the appearance of Ag1422. Treatment with cytochalasin B (15 micrograms/ml) and/or colchicine (100 microM) does not alter the restricted mobility of surface components seen on differentiated cells. Therefore, neither microfilaments nor microtubules seem to be involved in the mobility restriction. These observations are discussed in relation to current views of myogenesis.
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PMID:Changes in cell surface antigens during in vitro lizard myogenesis. 634 59

In this study we report the identification of an antibody in the sera of some patients with autoimmune disease that reacted with a cytoplasmic antigen localized within the Golgi apparatus. The antibody reacted with all tissues investigated, which included pancreas, kidney, testis, liver, thymus, and spleen. In addition, it reacted with some human peripheral circulating lymphocytes, murine peritoneal macrophages, and a variety of tissue culture cell lines, which included HEp-2 cells (human epithelial carcinoma), baby hamster kidney cells, a canine thymus cell line, a primary kidney cell line, Ehrlich ascites cells, Wil-2 cells, and Raji cells. The antigen is located in the same region stained by the histochemical reaction for thiamine pyrophosphatase, thus indicating that the antigen is located within the Golgi apparatus. The antigen was not demonstrated by immunodiffusion of saline extracts of rabbit thymus, pancreas, or liver. The antigen in HEp-2 cells was resistant to RNase A, DNase I, micrococcal nuclease, and to extraction with 0.1 N HC1, but was sensitive to trypsin and Proteinase K. Eight patients with anti-Golgi antibodies have been identified. Six of the eight had systemic lupus erythematosus. Autoantibodies to a Golgi apparatus antigen might serve as a useful biologic marker to study the functional relationship of the Golgi apparatus to lymphocytes and macrophages.
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PMID:Antibodies from patients with autoimmune disease react with a cytoplasmic antigen in the Golgi apparatus. 637 21

Ascaris trypsin inhibitors 1, 2, and 3 have arginine at their reactive P1 site. This corrects an earlier report that lysine is the reactive P1 site residue in Ascaris trypsin inhibitor 1 (Peanasky et al., 1974, Bayer Symposium V: Proteinase Inhibitors, pp. 649-666). The present work illustrates that the residue modification method of Fritz et al. (1969, Z. Physiol. Chem., 350, 933-944) may not be reliably interpreted when trypsin inhibitors have an unusually high lysine content (greater than 12% of the molecular weight of the inhibitor). Thus the following procedure is recommended: treat the inhibitor with maleic anhydride first and second with butanedione reagent; then remove the maleyl groups in an acid environment and determine the activity of the inhibitor. Immunoperoxidase staining shows that antibody to Ascaris trypsin inhibitor 1 binds to body wall muscle, intestine, eggs and sperm in cross-sections of Ascaris. Antibody to TLCK-porcine trypsin binds to the same tissues and at the same sites as the antibody to Ascaris trypsin inhibitor 1. This is the first demonstration that a protein that originated in the host has been found in the parasite, Ascaris. Analyses of homogenates and of extracts of separated tissues always show an excess of free trypsin inhibitor and no evidence of active trypsin. The host protein is present inside the parasite, probably as the trypsin-inhibitor complex.
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PMID:Trypsin inhibitors from Ascaris: the reactive P1 site of the inhibitors (a correction) and location of the inhibitors and host trypsin in cross-sections of Ascaris. 640 61

Proteinase Inhibitor I was induced to accumulate in tobacco (Nicotiana tabaccum) leaves by placing plants in darkness for 10 days at 27 degrees C. The inhibitor was isolated using ammonium sulfate precipitation, Sephadex G-75 chromatography, heating, and affinity chromatography with a chymotrypsin-Sepharose column. Inhibitor I was purified 232-fold with a yield of 34 mg from 2.5 kg of leaves. Affinity-purified tobacco Inhibitor I was shown to be homogeneous by gel electrophoresis in both nondissociating and dissociating buffers. The inhibitor has a molecular weight of 39,000 +/- 1000 determined by gel filtration and, like its potato and tomato counterparts, is composed of five subunits of molecular weight 8100. The tobacco Inhibitor I strongly inhibits chymotrypsin and weakly inhibits trypsin. The chemical, physical, and immunological properties of tobacco Inhibitor I indicate that it is structurally very similar to potato tuber Inhibitor I and tomato leaf Inhibitor I, although the synthesis and accumulation of the three inhibitors in their respective tissues are all under different developmental or environmental regulation.
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PMID:Isolation and characterization of proteinase inhibitor I from etiolated tobacco leaves. 642 73

Three different serine proteinase inhibitors were isolated from rat serum and purified to apparent homogeneity. One of the inhibitors appears to be homologous to alpha 1-proteinase inhibitor isolated from man and other species, but the other two, designated rat proteinase inhibitor I and rat proteinase inhibitor II, seem to have no human counterpart. alpha 1-Proteinase inhibitor (Mr 55000) inhibits trypsin, chymotrypsin and elastase, the three serine proteinases tested. Rat proteinase inhibitor I (Mr 66000) is active towards trypsin and chymotrypsin, but is inactive towards elastase. Rat proteinase inhibitor II (Mr 65000) is an effective inhibitor of trypsin only. Their contributions to the trypsin-inhibitory capacity of rat serum are about 68, 14 and 18% for alpha 1-proteinase inhibitor, rat proteinase inhibitor I and rat proteinase inhibitor II respectively.
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PMID:Proteinase inhibitors in rat serum. Purification and partial characterization of three functionally distinct trypsin inhibitors. 660 2

Proteolytic activity of the bovine rumen microflora was studied with azocasein as the substrate. Approximately 25% of the proteolytic activity of rumen contents was recovered in the strained rumen fluid fraction, and the balance of the activity was associated with the particulate fraction. The proportion of proteinase activity associated with particulate material decreased when the quantity of particulate material in rumen contents was reduced. The specific activity of the proteinase from the bacterial fraction was 6 to 10 times higher than that from the protozoal fraction. Proteinase inhibitors of synthetic, plant, and microbial origin were tested on proteolytic activity of the separated bacteria. Synthetic proteinase inhibitors that caused significant inhibition of proteolysis included phenylmethylsulfonyl fluoride, N-tosyl-1-lysine chloromethyl ketone, N-tosylphenylalanine chloromethyl ketone, EDTA, cysteine, dithiothreitol, iodoacetate, and Merthiolate. Plant proteinase inhibitors that had an inhibitory effect included soybean trypsin inhibitors types I-S and II-S and the lima bean trypsin inhibitor. Proteinase inhibitors of microbial origin that showed an inhibitory effect included antipain, leupeptin, and chymostatin; phosphoramidon and pepstatin had little effect. We tentatively concluded that rumen bacteria possess, primarily, serine, cysteine, and metalloproteinases.
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PMID:Proteolytic activity of rumen microorganisms and effects of proteinase inhibitors. 675 44

Proteinase inhibitor II' from adzuki beans was subjected to peptic digestion. One of the resulting fragments, which inhibited chymotrypsin but not trypsin, was composed of 27 amino acid residues. The fragment was confirmed to be derived from the chymotrypsin-inhibitory domain of the original inhibitor. Another fragment, which inhibited trypsin only, contained 38 amino acid residues and consisted of two peptide chains. One of them, consisting of 25 amino acid residues, corresponded to the original reactive site region for trypsin. These fragments were also obtained from inhibitor II by peptic digestion. These findings, confirm that these inhibitors, which do not inhibit chymotrypsin and trypsin simultaneously, have separate and independent domains for the inhibition of each enzyme. The active fragments are homologous in chemical structures with the two fragments from soybean Bowman-Birk proteinase inhibitor. However, unlike the fragments from Bowman-Birk inhibitor, our chymotrypsin-inhibitory fragment was a potent inhibitor of the enzyme and was as resistant as the intact inhibitor to the attack of excess chymotrypsin. The trypsin-inhibitory fragment had a lower anti-tryptic action than the original inhibitor and was gradually inactivated by trypsin. These differences between our fragments and those of the Bowman-Birk inhibitor are probably a result of the replacement of a few amino acid residues in the reactive site regions.
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PMID:Isolation and some properties of two fragments with inhibitory activity obtained from adzuki bean proteinase inhibitor by peptic digestion. 676 33


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