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

A detailed analysis is presented of the small-angle neutron scattering curves of homogeneous solutions of influenza B virus, both intact and after treatment with bromelain, which removes the external glycoprotein spikes. The two sets of data are consistent with the following low-resolution structure: the virus particles are spherical, about 1200 A in diameter and of Mr about 180 X 10(6). The lipid bilayer is centred at a radius of 425 A, is 40 A to 50 A thick and constitutes 25% to 28% of the virus mass. The surface glycoproteins, predominantly haemagglutinin, contribute 40% to 46% of the total mass. Surprisingly little protein is found in the interior of the virus. It is suggested that the reason for this is that many particles do not contain the full complement of ribonucleoprotein complexes. These results are in good agreement with recent scanning transmission electron microscopic measurements of molecular mass and cryo-electron microscopic observations of the same preparations. Appendix 1 describes a new method of deriving spherical shell models from contrast variation neutron scattering data on viruses, in which scattering curves from all measured contrasts are used simultaneously. There is also a discussion of the assumptions and limitations implicit in the structural interpretation of such models, with emphasis on viruses containing lipid bilayers. Appendix 2 examines the effect on the scattering curves of various arrangements of the surface glycoproteins.
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PMID:Structure and composition of influenza virus. A small-angle neutron scattering study. 409 79

gamma-Glutamyltransferase was solubilized from human hepatoma tissues by bromelain treatment, and some of its properties were compared with those of the normal adult liver enzyme. An electrophoretic study showed a slightly different mobility between the two enzymes before and after neuraminidase treatment. The hepatoma tissue enzyme was distinguished from the normal liver enzyme by decreased affinity to Con A. However, the enzymes from the two sources were found to be very similar or identical with respect to molecular weight, Michaelis constant, pH optimum, thermostability, effect of various L-amino acids as acceptors, behavior to divalent cations or ethylenediaminetetraacetate, inhibition by urea or sodium dodecyl sulfate, and immunological properties. These results suggest that the hepatoma tissue gamma-glutamyltransferase is largely due to altered glycosylation of this glycoprotein in hepatoma cells.
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PMID:gamma-Glutamyltransferase from human hepatoma tissue in comparison with normal liver enzyme. 611 82

Methods were developed for the purification of the surface, membrane-bound glycoproteins haemagglutinin and neuraminidase of influenza virus strain 3QB, in antigenically active forms. The methods employed in the purification included selective removal of the neuraminidase with the proteinase, bromelain, and subsequent disruption of the residual virus particle with the detergent Sarkosyl to release the haemagglutinin. Using techniques for proteolytic digestion of intact, native proteins an antigenically active peptide was isolated from the purified haemagglutinin, the surface glycoprotein against which the major antigenic response is directed. The amino acid composition of this peptide was determined. This was a 16-residue peptide with amino-terminal isoleucine and composition Ile1 Val1 Asx2 Thr1 Ser2 Glx2 Pro1 Gly3 Ala1 Leu1 Lys1.
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PMID:Purification of haemagglutinin and neuraminidase from influenza virus strain 3QB and isolation of a peptide from an antigenic region of haemagglutinin. 615 31

Antiserum to the p15(E) polypeptide of Rauscher murine leukaemia virus (R-MuLV) precipitated two proteins from purified virions of feline leukaemia virus (FeLV) with apparent mol. wt. of 18500 and 155000 on SDS-polyacrylamide gels. These proteins have been designated p15(E) and p12(E), in line with the nomenclature for MuLV proteins. Like the analogous protein of MuLV, FeLV p15(E) was found to be disulphide-linked to the virion glycoprotein, gp70. FeLV p15(E) was sensitive to digestion of intact virus particles with the proteolytic enzyme, bromelain, indicating that this protein is on the outer surface of the virion. An analysis of cat sera for precipitating activity for FeLV p12(E) showed this only in sera from cats which had recovered from FeLV infection and had virus-neutralizing activity.
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PMID:Polypeptides of feline leukaemia virus: identification of p15(E) and p12(E). 625 28

Rabbit antibody produced in response to the purified mitogenic glycoprotein lectin from Wistaria floribunda seeds (WFM) contains anti-carbohydrate antibody. This antibody, which represents 25% of the total antibody precipitated by the homologous antigen cross-reacts with the glycoprotein hemagglutinating lectins from Sophora japonica (SJL), W. floribunda (WFA) and the glycoprotein bromelain, but not the protein lectin from Maclura pomifera seeds. The cross-reactive reaction is totally abolished by the presence of glycopeptides obtained from SJL. Utilization of a fluorometric binding assay employing fluorescein derivatized glycopeptides from SJL, bromelain, fetuin and ovalbumin, it was found that the total anti-carbohydrate antibody population best reacts with the following carbohydrate structure: MAN alpha 1 leads to 6 MAN alpha 1 leads to 6 MAN beta 1 leads to 4 GLCNAC beta 1 leads to 4 GLCNAC beta 1 leads to Asn. Substitution of the beta-mannosyl moiety at position 3 results in structures not capable of binding to the anti-carbohydrate antibody. This antibody appears to distinguish between those glycan moieties of glycoproteins commonly found in animals from those lacking 3-O-substitution of the beta-mannosyl residue as found in some plant glycoproteins.
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PMID:Rabbit anti-carbohydrate antibody elicited by the lymphocyte mitogenic glycoprotein from Wistaria floribunda seeds. 641 71

We have detected an endoglycosidase activity produced by Flavobacterium meningosepticum. This enzyme, named endo F, cleaves glycans of both the high-mannose and the complex type linked through asparagine to the protein backbone. The data indicate that cleavage occurs via hydrolysis of the glycosidic bond of the N,N'-diacetylchitobiose core structure adjacent to asparagine, similar to that due to endo H and endo D. Extreme variability was noted in the availability of this cleavage site among N-linked glycoproteins. Glycoproteins of retrovirus, lymphocytic choriomeningitis virus, Pichinde virus, and HLA-A and -B antigens were readily cleaved in the presence of nonionic detergent. Others, such as ovalbumin, fetuin, bromelain, ovomucoid, alpha 1-acid glycoprotein, immunoglobulin G, and influenza virus hemagglutinin became susceptible only after reduction and alkylation or when cleavage was performed in the presence of 1% 2-mercaptoethanol. Endo F should prove useful in the study of glycans and protein backbones as discrete entities and for defining the nature of the glycan-protein interface.
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PMID:endo-beta-N-acetylglucosaminidase F: endoglycosidase from Flavobacterium meningosepticum that cleaves both high-mannose and complex glycoproteins. 681 50

Effects of bromelain (BR) on rabbit sputum consistency were investigated in vitro and in vivo. On the sputum showing relatively low viscosity, BR and other enzymes such as serratiopeptidase (SP), the mixed preparation of pronase and pancreatin, and lysozyme exerted lowering effects; and the effect of BR was the most potent. However, bromhexine had virtually no effect. On the sputum showing relatively high viscosity, BR exerted more potent lowering effects on the viscosity and yield value of sputum than those of SP. Furthermore, 320,000 U/head BR and 120,000 U/head SP lowered the viscosity significantly and yield value of sputum in rabbits with oral administration for 3 days. The lowering effect on the yield value of BR was more potent than that of SP. BR also increased the sputum volume in rabbits. BR and SP showed tendencies to decrease the contents of acid glycoprotein and sialic acid in sputum. It can be considered that these results support the effectiveness of BR as an expectorant in clinical use.
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PMID:[Experimental study of the effects of bromelain on the sputum consistency in rabbits]. 686 20

A conformational change in the hemagglutinin glycoprotein of influenza virus has been observed to occur to pH values corresponding to those optimal for the membrane fusion activity of the virus. CD, electron microscopic, and sedimentation analyses show that, in the pH range 5.2-4.9, bromelain-solubilized hemagglutinin (BHA) aggregates as protein-protein rosettes and acquires the ability to bind both lipid vesicles and nonionic detergent. Trypsin treatment of BHA in the pH 5.0-induced conformation indicates that aggregation is a property of the BHA2 component and that the conformation change also involves BHA1. The implications of these observations for the role of the glycoprotein in membrane fusion are discussed.
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PMID:Changes in the conformation of influenza virus hemagglutinin at the pH optimum of virus-mediated membrane fusion. 695 Nov 81

1. Neuraminidase was obtained by (A) bromelain solubilization or (B) by treatment with N-lauroylsarcosine. 2. 5-N-acetyl-2-O-(3-methoxyphenyl)-alpha-D-neuraminic acid, employed as substrate, avoids the interference produced by the thiobarbituric acid method, and is not interfered by the ampholytes. 3. Only about 20% of original enzyme activity was lost after electrofocusing. The sample from procedure A showed two peaks, corresponding to pIs 4.4 and 5.6. The sample from procedure B, having a higher activity, showed only one peak at pI 4.4. 4. Samples A and B showed different Km and hydrolysis rate with N-acetylneuraminyl-lactose and glycophorin A. It was not found significantly different with other substrates: alpha 1-acid glycoprotein, brain gangliosides, 5-N-acetyl-2-O-(3-methoxyphenyl)-alpha-D-neuraminic acid and 2'-(4-methyl umbelliferyl)-alpha-D-N-acetylneuraminic acid.
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PMID:Studies on neuraminidase from influenza virus A(H3N2) obtained by two procedures. 706 10

L-selectin, the peripheral lymph node "homing receptor," is an adhesion protein that mediates lymphocyte binding to lymph node high endothelial venules. Ligands for this protein have been identified only on endothelial cells, and recent murine studies indicate that CD34 on endothelial cells is an L-selectin ligand. To investigate whether CD34 expressed on hematopoietic cells functions as an L-selectin ligand, we used an in vitro binding assay to examine lymphocyte adherence to KG1a, a CD34+ human hematopoietic progenitor cell line. We observed specific L-selectin-mediated adherence of lymphocytes to KG1a: the binding was calcium-dependent, was strictly inhibited by anti-L-selectin antibodies and by carbohydrate ligands of L-selectin, and was abrogated by induction of L-selectin shedding from the lymphocyte membrane by treatment with phorbol esters. However, blocking studies using anti-CD34 antibodies, and experiments using KG1a cells sorted for CD34 expression and COS-7 cells transfected with full-length CD34 cDNA indicate that the ligand on KG1a is not CD34; moreover, RPMI 8402, a CD34+ cell line, does not support lymphocyte adherence in the binding assay. Treatment of KG1a with the enzymes neuraminidase, chymotrypsin, and bromelain abrogated lymphocyte binding to the cells, indicating that the ligand is a glycoprotein. These experiments show that CD34 on hematopoietic cells is not an L-selectin ligand and provide the first evidence of a ligand for L-selectin present on a non-endothelial cell.
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PMID:Detection of an L-selectin ligand on a hematopoietic progenitor cell line. 752 35


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