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Query: EC:4.2.2.10 (
PNL
)
341
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
An arabinoxylan-rhamnogalacturonan complex, comprised of galacturonic acid, rhamnose, arabinose, xylose, and
galactose
in the ratios 75.9:4.6:5.2:3.5:5.4 and lesser amounts of other constituents, was dissociated from the water-insoluble matrix of cell walls of Zea mays by xylanase and glucuronoxylanase treatment. The solubilized complex retained its integrity when subjected to a series of separation procedures, and analysis of the sugar components throughout the elution profiles exhibited consistent ratios. The complex was subjected to controlled degradation by pectate lyase and
pectin lyase
, yielding two components comprised of rhamnose, fucose, arabinose, xylose,
galactose
, and galacturonic acid in the ratios 10.9:1.5:13.1:16.9:27.7:30.0 and 8.5:1.7:11.8:6.6:17.3:54.0, respectively, in addition to di-, tri-, and tetra-saccharides of galacturonic acid. The non-reducing terminals of the latter were characterized by the presence of 4,5-unsaturated hexuronic acid. The structural features of the two complex fractions were partially characterized.
...
PMID:Structural characterization of an arabinoxylan-rhamnogalacturonan complex from cell walls of Zea shoots. 149 30
The production of pectinase was studied in Neurospora crassa, using the hyperproducer mutant exo-1, which synthesized and secreted five to six times more enzyme than the wild-type. Polygalacturonase,
pectin lyase
and pectate lyase were induced by pectin, and this induction was glucose-repressible. Polygalacturonase was induced by
galactose
four times more efficiently than by pectin; in contrast the activity of lyases was not affected by
galactose
. The inducing effect of
galactose
on polygalacturonase was not glucose-repressible. Extracellular pectinases were separated by ion exchange chromatography. Pectate and pectin lyases eluted into three main fractions containing both activities; polygalacturonase eluted as a single, symmetrical peak, apparently free of other protein contaminants, and was purified 56-fold. The purified polygalacturonase was a monomeric glycoprotein (38% carbohydrate content) of apparent molecular mass 36.6-37.0 kDa (Sephadex G-100 and urea-SDS-PAGE, respectively). The enzyme hydrolysed predominantly polypectate. Pectin was also hydrolysed, but at 7% of the rate for polypectate. Km and Vmax for polypectate hydrolysis were 5.0 mg ml-1 and 357 mumol min-1 (mg protein)-1, respectively. Temperature and pH optima were 45 degrees C and 6.0, respectively. The purified polygalacturonase reduced the viscosity of a sodium polypectate solution by 50% with an increase of 7% in reducing sugar groups. The products of hydrolysis at initial reaction times consisted of oligogalacturonates without detectable monomer. Thus, the purified Neurospora crassa enzyme was classified as an endopolygalacturonase [poly(1,4-alpha-D-galacturonide) glycanohydrolase; EC 3.2.1.15].
...
PMID:Pectinase production by Neurospora crassa: purification and biochemical characterization of extracellular polygalacturonase activity. 183 96
Monospecific antibodies directed to a Thomsen-Friedenreich antigen (T-antigen) were obtained using artificial antigen. T-antigen immunodominant alpha-disaccharide Galbeta (1----3) GalNAc alpha 1-(T alpha) and its beta-anomer Gal beta (1----3) GalNAc beta 1-(T beta) were bound to bovine serum albumin (BSA) and cytochrome C (CCC) through a spacer (sp = -O(CH2)3NHCO (CH2)4CO-) by the azide method to give neoglycoproteins T alpha-sp-BSA, T alpha-sp-CCC and T beta-sp-BSA. Anti-T alpha antiserum was obtained by immunization of rabbits with T alpha-sp-BSA and then purified by sequential affinity chromatography on BSA-Sepharose and T alpha-sp-BSA-Sepharose to yield monospecific anti-T IgG antibodies. As elucidated by ELISA method, binding T alpha-sp-BSA to the antibodies was inhibited by T alpha-sp-CCC, T alpha-sp-OEt, asialofetuin, T alpha-OBzl, the activity of the inhibitors decreasing in the above order. Methyl beta-
galactopyranoside
, benzyl 2-acetamido-2-deoxy-alpha-D-
galactopyranoside
, disaccharide Gal beta (1----3) GalNAc and H-sp-BSA were inactive. The inhibitory analysis suggests that both disaccharide moiety T alpha- and a definite part of the spacer are important for the binding and that T alpha-OCH2 seems to be the minimal recognized structure. In immunoprecipitation tests the antibodies react with T alpha-sp-BSA but not with T beta-sp-BSA, whereas peanut (Arachis hypogaea) lectin (
PNL
) precipitated both T alpha- and T beta-sp-BSA. These data suggest the significance of the alpha-galactosaminide bond for the antibody recognition. Desialylated human erithrocites (natural T-antigen) were effectively agglutinated with the antibodies. Murine cortical thymocytes (obtained by agglutination-sedimentation method using
PNL
) were agglutinated with the antibodies only partially (67%), while these cells as well as the cells unaffected by the antibodies were completely agglutinated with
PNL
. These results indicate to different contents of glycoproteins (T alpha) and glycolipids (T beta) oligosaccharide determinants on the surface of cortical thymocytes species.
...
PMID:[Monospecific antibodies against synthetic T-antigen. Characteristics of their specificity and use in the identification of T-antigenic determinants on the cell surface]. 241 65
Histochemical study by traditional staining methods (AB, PAS, HID) and by the use of five peroxidase-labelled lectins (ConA, WGL, WPL, SBL,
PNL
) were carried out to characterize glycoconjugates in the secretory cells of the nasal mucosa of the Lacertid lizard Podarcis sicula campestris De Betta. The mucus covering the nasal epithelium is produced by the supporting cells and the Bowman glands in the olfactory area, and by typical goblet cells and, probably, a second type of secretory cell, in the non-sensory area. Neutral glycoconjugates containing N-acetyl-D-glucosamine and terminal N-acetyl-D-galactosamine,
D-mannose
and
D-glucose
residues were present in the secretory product of the Bowman glands. L-fucose and D-
galactose
were absent. In the supporting cells the secretory product consisted mainly of sulfated glycoproteins containing D-
galactose
, N-acetyl-D-galactosamine, N-acetyl-D-glucosamine,
D-mannose
,
D-glucose
, but not L-fucose. Glycoconjugates containing terminal sialic acid and penultimate D-
galactose
were present in typical goblet cells as was N-acetyl-D-glucosamine.
...
PMID:Lectin histochemistry of secretory cell glycoconjugates in the nasal mucosa of Podarcis sicula campestris De Betta (Reptilia, Lacertidae). 281 23
We investigated the structure of glycoconjugates contained within the secretory end-pieces and ductal segments in the rabbit submandibular and sublingual glands. Glycosidic sequences were examined by means of enzymatic degradation with specific glycosidases (sialidase, alpha-fucosidase, beta-galactosidase, alpha-mannosidase) followed by lectin binding with
PNL
-HRP, WPL-HRP, WGL-HRP, SBL-HRP, Con A-HRP. It was found that this procedure represents a valid tool for studying carbohydrates, in so far as their characterization and localization were based only on colour reactions. In particular, this research showed that sialic acid was present in the terminal dimers sialic acid-beta-
galactose
and sialic acid-N-acetyl-D-galactosamine within the submandibular gland, whereas in the sublingual gland it was only present as the sequence sialic acid-beta-
galactose
. Conversely, fucose had as the subterminal sugar N-acetyl-D-glucosamine in both glands. Also, elucidations about structural sequences concerning other non-terminal sugars were obtained.
...
PMID:Visualization of carbohydrate chains in rabbit salivary glands by means of enzymatic degradation and plant lectins. 314 37
Mucous cells and enteroendocrine cells of the pyloric region of the ruin lizard (Podarcis sicula campestris De Betta) have been examined by lectin histochemical and immunohistochemical methods. Binding to five plant lectins (Canavalia ensiformis, Con A; Triticum vulgare, wheat germ, WGL; Lotus tetragonolobus, winged pea, WPL; Glycine max, soybean, SBL; Arachis hypogaea, peanut,
PNL
) was performed to characterize glycoconjugates in the secretory products of superficial and glandular mucous cells. Lectin histochemistry revealed the presence of N-acetyl-D-galactosamine, D-
galactose
and N-acetyl-D-glucosamine in the pyloric superficial cells. Mucous glandular cells mainly contained neutral glycoproteins with terminal residues of
galactose
, N-acetyl-D-glucosamine and N-acetyl-D-galactosamine. These cells did not react with Con A after periodate oxidation-sodium borohydride reduction (Paradoxical Con A staining). In the pyloric glands three different types of endocrine cells were identified immunohistochemically: gastrin-, serotonin- and somatostatin-immunoreactive cells; VIP-, bombesin- or cholecystokinin-immunoreactive cells have not been found in the pyloric mucosa.
...
PMID:Immunohistochemical investigations on the pyloric glands of the ruin lizard (Podarcis sicula campestris de Betta). 791 80
The effects on liver function and hepatic lidocaine elimination using 20% Intralipid as a source of non-protein calories (30%) in parenteral nutrition were studied using an isolated rat liver perfusion procedure. Rats were randomly assigned to one of the three treatment groups:
PNL
group (n = 6), consisting of 16.94%
dextrose
, 2.46% Intralipid, and 5.2% amino acids; PN group (n = 5), consisting of 24.2%
dextrose
and 5.2% amino acids; and CF group (n = 6), chow fed (rat chow and water). The rate of lidocaine metabolism was significantly reduced after 7 d in the two PN treated groups when compared to CF. Steatosis was observed in five out of six
PNL
treated animals and two out of five PN treated animals. Intrinsic clearance was reduced by 80% in the
PNL
group and by 60% in the PN animals (p < 0.05). Molar metabolite to drug ratios revealed significant reductions in N-dealkylation, m-hydroxylation, and aryl methyl hydroxylation in groups
PNL
and PN; these values amounted to 67-92% (p < 0.05). These findings suggest that a
dextrose
-amino acid solution induced steatosis and reduced the rate of lidocaine metabolism. The incorporation of Intralipid caused further deterioration.
...
PMID:Effects of intravenous lipid as a source of energy in parenteral nutrition associated hepatic dysfunction and lidocaine elimination: a study using isolated rat liver perfusion. 942 44
Three bacterial pectate lyases, a
pectin lyase
from Aspergillus niger, the structures of rhamnogalacturonase A from Aspergillus aculeatus, RGase A, and the P22-phage tailspike protein, TSP, display the right-handed parallel beta-helix architecture first seen in pectate lyase. The lyases have 7 complete coils while RGase A and TSP have 11 and 12, respectively. Each coil contains three beta-strands and three turn regions named PB1, T1, PB2, T2, PB3, and T3 in their order of occurrence. The lyases have homologous sequences but RGase A and TSP do not show obvious sequence homology either to the lyases or to each other. However, the structural similarities between all these molecules are so extensive that divergence from a common ancestor is much more probable than convergence to the same fold. The region PB2-T2-PB3 is the best conserved region in the lyases and shows the clearest structural similarity. Not only is the pleating and the direction of the hydrogen bonding in the sheets conserved, but so is the unusual alphaL-conformation turn between the two sheets. However, the overall shape, the position of long loops, a conserved alpha-helix that covers the amino-terminal end of the parallel beta-helix and stacks of residues in alphaR-conformation at the start of PB1 all suggest a common ancestor. The functional similarity, that the enzymes all bind
alpha-galactose
containing polymers at an equivalent site involving PB1 and its two flanking turn regions, further supports divergent evolution. We suggest that the stacking of the coils and the unusual near perpendicular junction of PB2 and PB3 make the parallel beta-helix fold especially likely to maintain similar main chain conformations during divergent evolution even after all vestige of similarity in primary structure has vanished.
...
PMID:Structure and evolution of parallel beta-helix proteins. 972 25
The exo-1 mutant of Neurospora crassa produced and secreted pectolytic activities when incubated in the presence of pectin-containing biological materials. This study shows that polygalacturonase, pectate lyase and
pectin lyase
activities were induced in media supplemented with
galactose
or galacturonic acid, indicating that these sugars induced the synthesis of pectinases. Pectinesterase activity was undetectable. Polygalacturonase activity was better induced by
galactose
than by galacturonic acid. The reverse was true for lyase activities. The inducing effect of
galactose
and galacturonic acid seemed to be different: (i) a mixture of
galactose
and galacturonic acid synergistically increased the production of pectic enzymes, as compared to that in the presence of one of these sugars; (ii) the inducing effect of galacturonic acid was partially repressed by glucose; (iii) in contrast, the inducing effect of
galactose
, rather than repressed, was enhanced by the presence of glucose. Altogether, these data point out to a complex mechanism of regulation of pectolytic enzymes by pectin-containing organic substances.
...
PMID:Regulation of pectic enzymes from the exo-1 mutant strain of Neurospora crassa: effects of glucose, galactose, and galacturonic acid. 972 23
Germlings of Botrytis cinerea, an important fungal pathogen of plants, produce an extracellular matrix (ECM), or ensheathing film, that serves, in part, in their attachment (R. P. Doss, et al., Appl. Environ. Microbiol. 61:260-265, 1995). The composition of this film has been ascertained by using samples obtained by growing germlings on a glass surface, removing the fungal mycelium by vigorous washing, and collecting the tightly attached film by scraping the substratum with a razor blade. Slightly over half of the dry weight of the ECM was found to be carbohydrates (about 20%), proteins (about 28%), and lipids (about 6%). Hydrolysis of the carbohydrate portion of the ECM revealed that glucose was the most prominent monosaccharide present, comprising about 60% of the total monosaccharides. Also present were
mannose
(about 35%) and myo-inositol (about 5%). The proteinaceous fraction of the ECM was made up of a number of polypeptides separable by polyacrylamide gel electrophoresis. The lipid fraction of the ECM, analyzed by thin-layer chromatography, was made up of several simple lipid components, including free fatty acid, mono- and triacylglycerol, wax ester, fatty alcohol, and several unidentified components. No complex lipids were detected. Isolated ECM exhibited polygalacturonase and laccase activity and was able to catalyze the hydrolysis of p-nitrophenyl butyrate, a model substrate for assessing cutinase activity. Cellulase,
pectin lyase
, and pectin methyl esterase activities were noted with both heated and unheated ECM preparations. Proteinase activity was not detected.
...
PMID:Composition and enzymatic activity of the extracellular matrix secreted by germlings of botrytis cinerea. 992 60
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