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)

Young adult Sprague-Dawley rats were partially hepatectomized (two-thirds organ removal) and administered a basal diet supplemented with various animal- and plant-derived enzymes (trypsin, alpha-chymotrypsin, pepsin, lipase, alpha-amylase, malt diastase, ficin and bromelain) over a post-operative period of up to 10 days. Porcine or bovine dialyzed and lyophilized crystalline trypsin products containing 2400-3200 NF u/mg in addition to enteric-coated tablets with trypsin to chymotrypsin in a ratio of 6:1, were tested at supplementary levels of up to 4980 u/g ration. With the weight of tissue regenerated or the liver increment as indicator, trypsin in excess of 1000-1200 u/g ration proved inhibitory. This effect did not extend to alpha-chymotrypsin (levels of up to 4000 u/g diet) and the remaining 6 enzyme products specified above, nor to the s.c. injection of trypsin daily at 12,860 u/rat for the 1st 7 days. The last route promoted little change in increment with soy bean trypsin inhibitor (8.0 mg/rat daily for days 1 to 9). When a portion of the group fed a trypsin supplement of 2000 u/g was injected with phenobarbital i.p. at 80 mg/kg daily on each of the last 3 days, the resulting liver increment rose to the control range. As with lysine and arginine, acids of pertinence in tryptic proteolysis, no significant change was elicited by feeding a diet supplemented with peptone from tryptic digestion of casein. The enzyme-containing diets fed to sham-operated rats over a similar interval, did not affect the wet- or dry-liver weight per 100 g body weight. Microsomal parameters as total protein, cytochrome P-450 and the enzymes, aminopyrine demethylase and benzo[a]pyrene hydroxylase of livers from the partially hepatectomized or sham-operated rats fed trypsin and the other enzyme diets, presented no significant changes in the respective levels. The possible action of dietary trypsin in conjunction with inhibitors and growth factors controlling liver regeneration is discussed.
 ...
PMID:Liver regeneration in trypsin-fed partially hepatectomized rats. 843 34

Two fluorescent conjugates of sialic acid have been prepared, with a convenient synthetic route that involves preparation of an unsaturated benzyl ester by cross-metathesis, followed by combined hydrogenation/ hydrogenolysis to provide a sialoside bearing a delta-carboxybutyl group, suitable for coupling with the chosen fluorophores. The fluorescent conjugates bound to bromelain-cleaved hemagglutinin (BHA) with affinities in the low microM range. Binding was accompanied by approximately 4.5-fold fluorescence enhancement for the dansyl conjugate 1 and approximately 3-fold fluorescence quenching for the pyrene conjugate 3.
 ...
PMID:Fluorescent ligands for the hemagglutinin of influenza A: synthesis and ligand binding assays. 1722 77

Interaction of the plant cysteine protease bromelain with SDS has been studied using CD spectroscopy, intrinsic fluorescence emission, extrinsic fluorescence probe pyrene, isothermal calorimetric (ITC) investigations and inhibition of hydrolyzing activity. Results exhibit number of synchronous transitions when plotted against the total SDS concentration. SDS at submicellar level caused conformation change of bromelain leading to a stable entity. ITC and pyrene experiments suggest that the structural modifications below 5 mM, the cmc(app) of SDS solutions containing bromelain, are the result of alterations of solvent hydrophobicity or non-specific weak binding and/or adsorption of SDS monomers. Melting temperature (T(m)) and the free energy change for thermal unfolding (DeltaG(unf)) of the SDS induced conformers was decreased by 5 degrees C and 0.5 kcal/mol respectively, compared to native bromelain. Below 5 mM, SDS caused large decrease in V(max) without affecting K(m) for the substrate Z-Arg-Arg-NHMec. Analysis of kinetic data imply that SDS acts as a partial non-competitive inhibitor since even at 100 mM, the residual activity of bromelain was retained by 3%. Inhibition studies show an IC(50) of 0.55 mM and a high K(i) of 0.145 mM. These demonstrate that bromelain is resistant to SDS binding and denaturation, a property known for beta-sheet rich kinetically stable proteins.
 ...
PMID:Resistance of bromelain to SDS binding. 1916 52