Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.22.32 (bromelain)
 1,025 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have observed that treatment of rabbit synovial fibroblasts with proteolytic enzymes can induce secretion of collagenase (EC 3.4.24.7) and plasminogen activator (EC 3.4.21.-). Cells treated for 2-24 hr with plasmin, trypsin, chymotrypsin, pancreatic elastase, papain, bromelain, thermolysin, or alpha-protease but not with thrombin or neuraminidase secreted detectable amounts of collagenase within 16-48 hr. Treatment of fibroblasts with trypsin also induced secretion of plasminogen activator. Proteases initiated secretion of collagenase (up to 20 units per 10(6) cells per 24 hr) only when treatment produced decreased cell adhesion. Collagenase production did not depend on continued presence of proteolytic activity or on subsequent cell adhesion, spreading, or proliferation. Routine subculturing with crude trypsin also induced collagenase secretion by cells. Secretion of collagenase was prevented and normal spreading was obtained if the trypsinized cells were placed into medium containing fetal calf serum. Soybean trypsin inhibitor, alpha(1)-antitrypsin, bovine serum albumin, collagen, and fibronectin did not inhibit collagenase production. Although proteases that induced collagenase secretion also removed surface glycoprotein, the kinetics of induction of cell protease secretion were different from those for removal of fibronectin. Physiological inducers of secretion of collagenase and plasminogen activator by cells have not been identified. These results suggest that extracellular proteases in conjunction with plasma proteins may govern protease secretion by cells.
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PMID:Proteases induce secretion of collagenase and plasminogen activator by fibroblasts. 20 72

A blood coagulation factor, Factor XIII, was highly purified from bovine fresh plasma by a method similar to those used for human plasma Factor XIII. The isolated Factor XIII consisted of two subunit polypeptides, a and b chains, with molecular weights of 79,000 +/- 2,000 and 75,000 +/- 2,000, respectively. In the conversion of Factor XIII to the active enzyme, Factor XIIIa, by bovine thrombin [EC 3.4.21.5], a peptide was liberated. This peptide, designated tentatively as "activation peptide," was isolated by gel-filtration on a Sephadex G-75 column. It contained a total of 37 amino acid residues with a masked N-terminal residue and C-terminal arginine. The whole amino acid sequence of "Activation peptide" was established by the dansyl-Edman method and standard enzymatic techniques, and the masked N-terminal residue was identified as N-acetylserine by using a rat liver acylamino acid-releasing enzyme. This enzyme specifically cleaved the N-acetylserylglutamyl peptide bond serine and the remaining peptide, which was now reactive to 1-dimethylamino-naphthalene-5-sulfonyl chloride. A comparison of the sequences of human and bovine "Activation peptide" revealed five amino acids replacements, Ser-3 to Thr; Gly-5 to Arg; Ile-14 to Val; Thr-18 to Asn, and Pro-26 to Leu. Another difference was the deletion of Leu-34 in the human peptide. Adsorption chromatography on a hydroxylapatite column in the presence of 0.1% sodium dodecyl sulfate was developed as a preparative procedure for the resolution of the two subunit polypeptides, a or a' chain and b chain, constituting the protein molecule of Factor XIII or Factor XIIIa. End group analyses on the isolated pure chains revealed that the structural change of Factor XIII during activation with thrombin occurs only in the N-terminal portion of the a chain, not in the N-terminal end of the b chain or in the C-terminal ends of the a and b chains. From these results, it was concluded that the activation of bovine plasma Factor XIII by thrombin must be accompanied by a limited proteolysis of the arginyl-glycyl bond located in the N-terminal region of the a chain, liberating the "Activation peptide." The possibility of activating Factor XII with other porteinases was examined using Factor Xa [EC 3.4.21.6], Factor XIIa, kallikreins [EC 3.4.21.8], urokinase [EC 3.4.99.26], trypsin [EC 3.4.21.4], ficin [EC 3.4.22.3], papain [EC 3.4.22.2], and bromelain [EC 3.4.22.4]. Among these enzymes, only bromelain and trypsin showed clear activating effects.
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PMID:On the activation of bovine plasma factor XIII. Amino acid sequence of the peptide released by thrombin and the terminal residues of the subunit polypeptides. 122 22

The reactivity of mouse antibodies against bromelain-treated mouse erythrocytes (BrMRBC) with mouse platelets before and after thrombin treatment was assessed by flow cytometry. Anti-BrMRBC antibodies could bind to thrombin-treated platelets, although normal platelets were also weakly reactive with the antibodies. The binding of anti-BrMRBC antibodies to platelets was confirmed by complement-dependent lysis. It is suggested that thrombin-activated platelets may be a real target for anti-BrMRBC antibodies.
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PMID:Reactivity of mouse antibodies against bromelain-treated mouse erythrocytes with thrombin-treated mouse platelets. 246 76

It has been established that a bromelain plasminogen activator will produce plasmin in rat experiments. In addition the plasmin cleaves Hageman factor in a way that leads to a strong release of kallikrein but a weak release of thrombin. A possible mechanism is suggested to explain how the body can maintain thrombin at a level too low to cause platelet aggregation but adequate to stimulate release of prostaglandins and enzymes for more than 24 hours from a single dose of the pineapple enzymes. Since bromelain therapy leads to formation of platelets with increased resistance to aggregation, it is obvious that the dominant endogenous prostaglandins being produced must be from the group that increases platelet cyclicAMP levels (prostacyclin, PGE1, etc.). The combination of fibrinolytic and antithrombic properties appear to be effective and two large scale tests on heart patients have shown a practically complete elimination of thrombosis.
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PMID:Fibrinolytic and antithrombotic action of bromelain may eliminate thrombosis in heart patients. 625 12

Ovalbumin is partially homologous in sequence with the proteinase inhibitors alpha 1-proteinase inhibitor and anti-thrombin III. The region of sequence in ovalbumin which corresponds to the reactive sites of these proteinase inhibitors is susceptible to attack by subtilisin, elastase, thermolysin, bromelain, and Bacillus cereus protease. The esterase activity of elastase is not inhibited by ovalbumin, but ovalbumin is efficiently cleaved by elastase. In contrast with these proteases, trypsin does not cleave ovalbumin.
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PMID:Ovalbumin is an elastase substrate. 656 26

Activation of bovine plasma prekallikrein was investigated with several proteinases. Highly purified bovine plasma prekallikrein was rapidly activated to kallikrein [EC 3.4.21.8] by bovine activated Hageman factor, trypsin [EC 3.4.21.4] and Pronase P (proteinases from Streptomyces griseus) and more gradually by papain [EC 3.4.22.2] and ficin [EC 3.4.22.3]. Activation of prekallikrein was also observed with bovine plasmin [EC 3.4.21.7], but not with bovine clotting factors Xa (Stuart factor) [EC 3.4.21.6] and IXa (Christmas factor) or thrombin [EC 3.4.21.5]. Urokinase [EC 3.4.99.26], Reptilase, collagenase [EC 3.4.24.3], elastase [EC 3.4.21.11], alpha-chymotrypsin [EC 3.4.21.1], Nagarse [EC 3.4.21.14], and stem bromelain [EC 3.4.22 4] did not convert prekallikrein to kallikrein. Plasma kallikrein activated to Hageman factor released kinin rapidly from bovine high molecular weight (HMW) kininogen. However, from bovine low molecular weight (LMW) kininogen, liberation of kinin was extremely slow. The kallikrein activity was inhibited by soybean trypsin inhibitor (SBTI), Trasylol, diisopropylfluorophosphate (DFP), and N-alpha-tosyl-L-lysine chloromethylketone (TLCK), but not by egg-white trypsin inhibitor (EWTI), lima bean trypsin inhibitor (LBTI), heparin or hexadimethrine bromide (Polybrene). The kallikrein formed an enzyme-inhibitor complex with SBTI and Trasylol, but not with LBTI. Prekallikrein did not react with SBTI. Prekallikrein consists of a single polypeptide chain of molecular weight about 90,000, as estimated by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis. Activation of prekallikrein by Hageman factor was found to involve cleavage of the single peptide bond on the disulfide-bridged polypeptide chain, and no change of molecular weight was observed during the activation. The peptide bond cleaved in prekallikrein by the activation was an Arg-X peptide bond on a disulfide-bridged polypeptide chain.
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PMID:Studies on prekallikrein of bovine plasma. II. Activation of prekallikrein with proteinases and properties of kallikrein activated by bovine Hageman factor. 676 24

The digestion of human GH (hGH) with the proteolytic enzyme, bromelain, results in a major product consisting of a mixture of three large fragments, i.e. residues 1-135 + 143-191, 1-135 + 145-191, and 1-135 + 146-191. In the case of each fragment, the N-terminal peptide is joined to the C-terminal fragment by the disulfide bridge between residues 56 and 165. A C-terminal fragment mixture consisting of peptides 143-191, 145-191, and 146-191 was isolated from this major digestion product after reduction and S-carbamidomethylation of its disulfide bonds. In the present study, the noncovalent complementation of the peptides in this mixture with S-carbamidomethylated peptide 1-134 derived from thrombin-digested hGH was investigated. Noncovalent complementation of these peptides was accomplished by dissolving equimolar amounts of the materials in 0.5% ammonium bicarbonate-6 M guanidine-HCl and dialyzing the mixture slowly to remove the guanidine-HCl. The recombinant mixture was recovered in 26% yield by gel filtration of the peptide mixture and was found to contain three noncovalent recombinant species, i.e. peptides 1-134 + 143-191, 1-134 + 145-191, and 1-134 + 146-191. Thus it would appear that residues 135-145 are not required to obtain noncovalent complementation between the N- and C-terminal regions of the hGH molecule. In an RIA for hGH the recombinant mixture was found to possess approximately 40% the cross-reactivity of the native hormone. In contrast, it had only about 10% the activity of native hGH in the weight gain test in hypophysectomized rats, in stimulating phenylalanine incorporation into the protein of the isolated hypophysectomized rat diaphragm, and in stimulating glucose oxidation by isolated adipose tissue of hypophysectomized rats. The limited biological activity of the recombinant mixture is of interest, since the major bromelain digestion product from which the C-terminal peptides were derived consists of a mixture of rather similar molecules (i.e. peptides 1-135 + 143-191, 1-135 + 145-191, 1-135 + 146-191; and with intact disulfide bridges), which exhibits substantial growth-promoting and insulin-like activities.
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PMID:Complementation of human growth hormone (GH) peptide 1-134 with C-terminal fragments of human GH produced by digestion with bromelain. 682 9

The thiol protease, bromelain, an extract from pineapple stem, was suggested to have antithrombotic and anticoagulant activities in vivo. We studied the effects of bromelain on cell size distribution of isolated human platelets in vitro by Coulter Counter measurements. Preincubation of platelets with bromelain (10 micrograms/mL) completely prevented the thrombin (0.2 U/mL) induced platelet aggregation. Papain was less active in preventing platelet aggregation. In vitro, bromelain (0.1 microgram/mL) reduced the adhesion of bound, thrombin stimulated, fluorescent labeled platelets to bovine aorta endothelial cells. In addition, preincubation of platelets with bromelain, prior to thrombin, activation, reduced the platelet adhesion to the endothelial cells to the low binding value of unstimulated platelets. On the basis of mass concentrations, the proteases papain and trypsin were as effective as bromelain. Using a laser thrombosis model, the in vivo effects of orally and intraveneously applied bromelain on thrombus formation in rat mesenteric vessels were studied. Bromelain, orally applied at 60 mg/kg body weight, inhibited the thrombus formation in a time dependent manner, the maximum being after 2 hours in 11% of arterioles and 6% of venoles. Intravenous application at 30 mg/kg was slightly more active in reducing thrombus formation in arterioles (13%) and venoles (5%), suggesting that orally applied bromelain is biologically active. These results may help to explain some of the clinical effects observed after bromelain treatment in patients with thrombosis and related diseases.
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PMID:Bromelain proteases reduce human platelet aggregation in vitro, adhesion to bovine endothelial cells and thrombus formation in rat vessels in vivo. 1021 25

The development of a simultaneous multiple substrate enzymatic assay based on electrospray ionization mass spectrometry (ESI-MS) detection is described. This multiplexing assay scheme was employed in a parallel proteolytic enzyme activity screening. As model systems, the respective activities of trypsin, thrombin, chymotrypsin, bromelain, ficin and elastase towards seven different substrates were assessed. The resulting activity patterns were evaluated semi-quantitatively ranking the enzymatic activities in five classes of activity (very high, high, medium, low and no activity) with respect to the individual substrates. The validity of the MS-based multiplexing assay scheme was proved by comparison with the results obtained from single substrate assays detected by means of UV/vis absorption at 405 nm, showing good agreement of the resulting activity patterns and classifications.
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PMID:Assessing protease activity pattern by means of multiple substrate ESI-MS assays. 1591 32

Bauninia forficata is trivially known as cow paw, and popularly used in Brazil for treatment of diabetes mellitus. Denominated baupain a cysteine proteinase was purified from B. forficata leaves. In this study, we investigated the baupain effect on aggregation of isolated human platelets in vitro and the results show that baupain hinders thrombin - but not ADP- and collagen- induced platelet aggregation. With synthetic quenched-fluorescent peptides, the kinetics of the cleavage site of human proteinase-activated receptor 1 / 2 / 3 and 4 [PAR-1 / 2 / 3 and 4] by baupain was determined. In conclusion, similar to bromelain and papain, baupain hinders human platelets aggregation, probably through an unspecific cleavage in the Phe-Leu bond of PAR1.
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PMID:Baupain, a plant cysteine proteinase that hinders thrombin-induced human platelet aggregation. 2218 3


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