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)

Two component random copolypeptide membranes, consisting of N-hydroxyalkyl L-glutamine and L-alanine or L-leucine were prepared by carrying out aminolysis reactions with 2-amino-1-ethanol (E) or 5-amino-1-pentanol (Pe), together with a cross-linking reaction with 1,8-octamethylenediamine (OMDA) on membranes of the starting copolymers consisting of gamma-benzyl L-glutamate (B) and L-alanine (A) or L-leucine (L). The relationships between their bulk structure and membrane properties were investigated, such as the swelling ratio in water, aqueous vapour permeability, tensile properties and enzymatic degradation behaviour of the membranes in a pseudo-extracellular fluid (PECF). The tensile properties of the hydrophilic membranes were highly dependent on the swelling ratio of PECF, and the hydrophobicity of the side chains, whose behaviour was typical of an elastomer. We showed that a common relation was obtained between the rate of water vapour permeability and the swelling ratio of membranes in PECF despite the difference of the nature of the side chains. Biodegradation of these membranes in vitro by bromelain indicated that the degradation was a bulk rather than a surface phenomenon, and that the rate of degradation was also highly dependent on the swelling ratio of samples and on the hydrophobicity of the side chains of samples.
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PMID:Biodegradation of random copolypeptide membranes consisting of N-hydroxyalkyl L-glutamine as one component. 832 21

Two component random copolypeptide hydrogels consisting of N-hydroxyalkyl L-glutamine and L-leucine were prepared by carrying out aminolysis reactions with 3-amino-1-propanol(P) together with cross-linking reactors with 1,8-octamethylenediamine (OMDA) on hydrogels of the starting copolymers consisting of gamma-methyl-L-glutamate(M) and L-leucine(L). The relation between their bulk structure and properties was investigated with regard to the swelling ration in water, aqueous vapor permeability, tensile properties, and enzymatic degradation behavior in a pseudoextracellular fluid (PECF). The tensile property of the hydrogels was highly dependent on the swelling ratio in PECF, and on the hydrophobicity of the side chains, whose behavior was typical of an elastomer. It was shown that a common relation was obtained between the rate of water vapor permeabilities and the swelling ratio of hydrogels in PECF regardless of the difference of the nature of side chains. Biodegradation of the hydrogels in vitro by bromelain indicated that the degradation took place in bulk rather than on surface, and that the rate of degradation was also highly dependent on the swelling ratio of samples as well as on the hydrophobicity of the side chains of samples.
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PMID:Enzymatic hydrolysis of copoly(N-hydroxypropyl-L-glutamine/L-leucine) hydrogels in vitro. 877 84

Based on the wheat glutenin IgE-binding epitope, Gln-Gln-Gln-Pro-Pro, a practical method is proposed for the production of hypoallergenic wheat flour. Bromelain was found effective for decomposing the epitope structure. In practice, soft flour was mixed with water dissolving bromelain and the mixture was incubated at 37 degrees C for 4 h. The result of IgE-ELISA (enzyme-linked immunosorbent assay) suggested negative allergenicity. A mixture of bromelain-modified flour, glucose, citric, acid, a surfactant and sodium hydrogen carbonate was baked to produce hypoallergenic bread, resembling English muffins.
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PMID:Modification of wheat flour with bromelain and baking hypoallergenic bread with added ingredients. 898 41

Matrix ligands are agents for isolating proteins out of dilute crudes by coprecipitating proteins. The ligands have a strong anion sulfonate head which initiates binding to proteins having a positive net charge, ZH+ approximately 5-20. Initial binding tightens protein conformation and starts to squeeze water from conformationally motile proteins. The tails are stackable hydrophobic organic groups, azoaromatic dyes which draw protein-ligand complexes together. Proteins coprecipitate as guests, in the ligand host matrix. In addition to stacking, ligand tails displace water because of their bulk, and lower the average dielectric constant near charged groups, which reinforces the electrostatic component of binding. Matrix ligands protect proteins, scavenge them from dilute crudes (0.01-0.1 per cent protein), and densify coprecipitates. Detergent ions in low concentrations, 10(-4)-10(-5) M also sometimes serve as coprecipitating agents, entangling their tails but probably not stacking. Divalent metal ions, Zn++, sometimes are useful auxiliary agents. Preparative scaleability from crudes is demonstrated starting from 100-200 g of raw peanuts and raw pineapple to coprecipitate a lectin and bromelain enzyme respectively in 1-2 h with 80-90 per cent activity yields. Ligands are released from coprecipitates by shifting the pH and trapping the ligands with exchange resins. Protein conformation tightening in solution is seen by viscosity measurements.
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PMID:Coprecipitation of proteins with matrix ligands: scaleable protein isolation. 917 21

It is revealed that patients allergic to a water-soluble fraction from wheat flour were sensitive to pineapple enzyme, bromelain. Since bromelain has a high similarity to other SH-proteases such as papain, it may imply that the patients may recognize varieties of other SH-proteases as the epitope.
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PMID:[Cross-reactivity between bromelain and soluble fraction from wheat flour]. 943 35

It has been demonstrated that intraperitoneal administration of proteolytic enzymes ameliorates the progression of renal diseases in various animal models. In the present study, we employed the rat remnant kidney model to study the effectiveness of oral administration of proteases. Twenty male Wistar rats underwent sham operation (CTRL), while 25 were subjected to 5/6 nephrectomy (5/6 NX). Rats were randomised into placebo (PL) (2 ml tap water/day by gavage), or Phlogenzym (E; fixed mixture of trypsin 2.42 mg, bromelain 4.54 mg, and rutozid 5.04 mg added as antioxidant, in 2 ml tap water daily by gavage) treated group. Duration of the study was 45 days. Rats were pair-fed. Enzyme treatment exerted salutary effects on various functional and morphological parameters. Proteinuria was higher in both 5/6 NX group rats throughout the study. Administration of proteases ameliorated its rise effectively (data at sacrifice: CTRL-PL 6.27 +/- 1.25, CTRL-E 9.27 +/- 0.99, 5/6 NX-PL 74.04 +/- 21.33, 5/6 NX-E 39.09 +/- 7.93 mg/24 h; P < 0.01). Increased urinary excretion of the fibrogenic cytokine transforming growth factor (TGF-beta 1) was improved, too (CTRL-PL 0.349 +/- 0.051, CTRL-E 0.693 +/- 0.230, 5/6 NX-PL 3.044 +/- 0.540, 5/6 NX-E 1.390 +/- 0.238 ng/mumol creatinine; P < 0.05). At sacrifice, tubulointerstitial fibrosis was less pronounced in E-treated rats. Correspondingly, the volume fraction of tubulointerstitial tissue in the renal cortex was improved in 5/6 NX-E rats (CTRL-PL 9.9 +/- 0.2, CTRL-E 10.0 +/- 0.2, 5/6 NX-PL 17.9 +/- 1.8, 5/6 NX-E 13.8 +/- 0.9%; P < 0.05). The protein/DNA ratio in isolated glomeruli and tubules, as an estimate of glomerular matrix accumulation and hypertrophy of tubules, was enhanced in 5/6 NX groups and a tendency towards lower values was observed after E treatment. Renal function as evaluated by serum creatinine and urea levels was not influenced by the enzyme therapy. No between-group differences in blood pressure were observed. In summary, oral administration of proteolytic enzymes improved proteinuria and urinary TGF-beta 1 excretion, as well as the severity of tubulointerstitial fibrosis without signs of toxicity.
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PMID:The effect of oral protease administration in the rat remnant kidney model. 1063 1

A novel inhibitor of cysteine proteinases has been isolated from fruit bodies of a mushroom Clitocybe nebularis. The inhibitor was purified to homogeneity by affinity chromatography and gel filtration, followed by reverse-phase high pressure liquid chromatography. The active inhibitor has an apparent molecular mass of about 34 kDa by gel filtration and by SDS-polyacrylamide gel electrophoresis without prior boiling of the sample. Boiling in 2.5% SDS or incubation in 6 m guanidine hydrochloride resulted in a single band of 17 kDa, indicating homodimer composition with no intersubunit disulfide bonds. The inhibitor in nondenaturing buffer is resistant to boiling in water, retaining its activity and dimer composition. The mushroom protein is a tight binding inhibitor of papain (K(i) = 0.59 nm), cathepsin L (K(i) = 0.41 nm), cathepsin B (K(i) = 0.48 micrometer), and bromelain (K(i) = 0.16 micrometer) but is inactive toward cathepsin H, trypsin, and pepsin. Its isoelectric point is 4.4, and sugar analysis indicates the absence of carbohydrate. A single protein sequence of 150 amino acids, containing no cysteine or methionine residues, was obtained by amino acid sequencing. The calculated molecular mass of 16854 Da corresponds well with the value obtained by mass spectrometry. A major part of this sequence was verified by molecular cloning. The monomer sequence is clearly devoid of typical cystatin structure elements and has no similarity to any other known cysteine proteinase inhibitors but bears some similarity to a lectin-like family of proteins from mushrooms. The inhibitor, which is present in at least two other members of the Clitocybe genus, has been named clitocypin (Clitocybe cysteine proteinase inhibitor).
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PMID:Clitocypin, a new type of cysteine proteinase inhibitor from fruit bodies of mushroom clitocybe nebularis. 1074 21

We have used in situ tapping mode atomic force microscopy (AFM) to study the structural morphology of two fragments of the influenza hemagglutinin protein bound to supported bilayers. The two proteins that we studied are the bromelain-cleaved hemagglutinin (BHA), corresponding to the full ectodomain of the hemagglutinin protein, and FHA2, the 127 amino acid N-terminal fragment of the HA2 subunit of the hemagglutinin protein. While BHA is water soluble at neutral pH and is known to bind to membranes via specific interactions with a viral receptor, FHA2 can only be solubilized in water with an appropriate detergent. Furthermore, FHA2 is known to readily bind to membranes at neutral pH in the absence of a receptor. Our in situ AFM studies demonstrated that, when bound to supported bilayers at neutral pH, both these proteins are self-assembled as single trimeric molecules. In situ acidification resulted in further lateral association of the FHA2 without a large perturbation of the bilayer. In contrast, BHA remained largely unaffected by acidification, except in areas of exposed mica where it is aggregated. Remarkably, these results are consistent with previous observations that FHA2 promotes membrane fusion while BHA only induces liposome leakage at low pH. The results presented here are the first example of in situ imaging of the ectodomain of a viral envelope protein allowing characterization of the real-time self-assembly of a membrane fusion protein.
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PMID:Self-assembly of influenza hemagglutinin: studies of ectodomain aggregation by in situ atomic force microscopy. 1147 88

Lambda DNA terminase, the enzyme that cleaves virion-length chromosomes from multigenomic concatemers and packages them into the bacteriophage head, is composed of two subunits, gpNu1 and gpA. Direct determination of the structure of gpNu1, the smaller subunit, has not been possible because of its insolubility in aqueous solutions. Therefore, to identify smaller and potentially water-soluble domains of gpNu1, we analyzed the nature of the products obtained by limited digestion of the protein with several proteases. The gpNu1 subunit was obtained from E. coli cells transfected with the plasmid pH6-Nu1 that overproduces the protein. Incubation of gpNu1 solubized in 2.5 M guanidinium chloride with chymotrypsin resulted in the formation of at least eight discrete protein bands, while treatment with endoproteinase glu-C and bromelain yielded three and one major bands, respectively. The peptides generated by digestion with the various proteases were separated by two-dimensional gel electrophoresis and transferred to Immobilon membranes. Amino acid sequencing of the peptides allowed for the precise assignment of their N-terminal amino acid, while their estimated molecular weights permitted the identification of their C-terminal ends. The results reveal that in the presence of 2.5 M guanidinium chloride, gpNu1 is partially folded in at least four distinct structural domains that correspond to functional domains as determined by previously reported genetic experiments. This information is key to design new plasmids to overproduce these domains for further structural analysis.
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PMID:The bacteriophage lambda DNA packaging enzyme: identification of four structural domains of the gpNu1 subunit using limited proteolysis. 1171 58

In the past year there have been many advances in the area of small bowel physiology and pathology and therapy. In preparation for this review, over 1500 papers were assessed. The focus is on presenting clinically useful information for the practising gastroenterologist. Selected important clinical learning points include the following: (1) glucose absorption mediated by SGLT1 is controlled by mRNA abundance, as well as by posttranscriptional processes including protein trafficking; (2) inducers of cytochrome P-450 decrease glucose and fructose absorption and increase glucose consumption in the intestine; (3) the regulated release of nutrients from the stomach into the upper intestine ensures that the modest intestinal transport reserve capacity is not exceeded; (4) hepatocyte growth factor and short-chain fatty acids may enhance intestinal adaptation and prevent the atrophy seen when total parenteral nutrition is infused; (5) inhibitors of pancreatic lipase and phospholipase H2 may be useful clinically to reduce absorption as part of a treatment program for obesity and hyperlipidemia; (6) several membrane-bound and cytosolic proteins have been identified in the enterocyte as well as in the hepatocyte and may be the target for the future therapeutic manipulation of bile acid metabolism and control of hyperlipidemia; (7) suspect bile acid malabsorption in the patient with otherwise unexplained chronic diarrhea; (8) a proportion of lipid absorption is protein-mediated, and this opens the way to targeting these proteins and thereby therapeutically modifying lipid absorption; (9) a high protein diet may be useful to increase the intestinal absorption of drugs transported by the H+/dipeptide cotransporter; (10) a metal transporter DCT1 has been identified, and this may open the way to a better understanding of disorders of, for example, iron and zinc metabolism; (11) the nutrient transporters such as SGLT1 are responsible for a portion of the intestinal absorption of water; (12) the influence of nitric oxide on intestinal water absorption and secretion depends on its concentration; (13) a trial of bile acid-sequestering agent may prove useful in the treatment of the patient who experiences diarrhea while taking an enteral diet; (14) a proteolytic extract from pineapple stems may prove to be useful to treat diarrhea, although the mechanism of this effect remains to be established; and (15) the antisecretory effect of the new peptide, sorbin, needs to be tested in a clinical situation on patients with diarrhea. Other new and promising antidiarrheal agents include bromelain, an extract from pineapple stems, and igmesine, a final sigma ligand.
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PMID:Small bowel review: normal physiology part 1. 1176 47


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