DEGRADATION OF RUTIN BY ASPERGILLUS FLAVUS. PURIFICATION AND CHARACTERIZATION OF RUTINASE

1961 ◽  
Vol 7 (6) ◽  
pp. 921-932 ◽  
Author(s):  
G. W. Hay ◽  
D. W. S. Westlake ◽  
F. J. Simpson
Keyword(s):  
Aspergillus Flavus ◽  
Partial Purification ◽  
Dihydroxybenzoic Acid ◽  
Purification And Characterization ◽  
Dihydroxyphenylacetic Acid ◽  
The Common ◽  
Hydrolysis Of

Aspergillus flavus produces an adaptive glycosidase (rutinase) that hydrolyzes rutin to quercetin and rutinose. Production of rutinase occurs when the mold is grown on the glycosides rutin, hyperosid, and naringin, and on the aglycones quercetin, kaempferol, rhamnetin, 2,4-dihydroxybenzoic acid, and 3,4-dihydroxyphenylacetic acid, but not when grown on glucose, galactose, rhamnose, or rutinose. Rutinase, after partial purification, is relatively stable when stored at −20 °C, and is most stable and most active at pH 5.6. The enzyme is quite specific, hydrolyzing the 5-glucoside of sakuranetin, the 3-rutinoside and 3-galactoside of quercetin, but not the 3-L-rhamnoside nor any of the common glycosides. The hydrolysis of rutin is carried to completion aided by the insolubility of the aglycone quercetin in water.

DEGRADATION OF RUTIN BY ASPERGILLUS FLAVUS. PRODUCTION, PURIFICATION, AND CHARACTERIZATION OF AN ESTERASE

1963 ◽  
Vol 9 (5) ◽  
pp. 653-664 ◽  
Author(s):  
J. J. Child ◽  
F. J. Simpson ◽  
D. W. S. Westlake
Keyword(s):  
Aspergillus Flavus ◽  
Tannic Acid ◽  
Absorption Maximum ◽  
Potassium Ferricyanide ◽  
Ethyl Butyrate ◽  
Dihydroxybenzoic Acid ◽  
Purification And Characterization

Aspergillus flavus produces an inducible esterase that hydrolyzes the depside, 2-(3′,4′-dihydroxybenzoyloxy)-4,6-dihydroxybenzoic acid. The activity of this enzyme may be followed by measurement of the rate of production of protocatechnic acid, which reacts with alkaline potassium ferricyanide to give a product with an absorption maximum at 540 mμ. Synthesis of the esterase is induced when the organism is grown on rutin, robinin, hyperosid, kaempferol, rhamnetin, myricetin, quercetin, and fisetin, but not when grown on apigenin, galangin, glucose, naringenin, morin, rhamnose, robinetin, or taxifolin. The esterase has been partially purified and separated from the rutinase and quercetinase enzymes. The esterase is most active at pH 4.5. Eighty percent of the activity remained after holding the enzyme for 10 minutes at 60 °C. The enzyme readily attacked the depside linkages in tannic acid but did not hydrolyze common ester substrates such as ethyl butyrate.

Post-proline endopeptidase. Partial purification and characterization of the enzyme from pig kidneys

1982 ◽  
Vol 47 (4) ◽  
pp. 1139-1148 ◽  
Author(s):  
Karel Hauzer ◽  
Linda Servítová ◽  
Tomislav Barth ◽  
Karel Jošt
Keyword(s):  
Specific Activity ◽  
Gel Filtration ◽  
Peptide Bond ◽  
Exchange Chromatography ◽  
Partial Purification ◽  
Purification And Characterization ◽  
Optimum Ph ◽  
Hydrolysis Of ◽  
Prolyl Leucyl Glycinamide

Post-proline endopeptidase was isolated from pig kidneys and partially purified. The procedure consisted of fractionation with ammonium sulphate, ion exchange chromatography on DEAE-Sephadex A-50, gel filtration on Sephadex G-200 and rechromatography on DEAE-Sephadex A-50. The preparation had 55 times higher specific activity than the crude extract and did not contain any contaminating enzymic activities. The enzyme cleaved a number of proline-containing peptides and was strictly specific in catalyzing the hydrolysis of the peptide bond on the carboxyl side of the proline residue. The optimum pH for the hydrolysis of the synthetic peptides benzyl-oxycarbonylglycyl-prolyl-leucyl-glycinamide and benzyloxycarbonyl-glycyl-proline β-naphtylamide was 7.8-8.0 and, in the case of benzyloxycarbonylglycyl-proline p-nitroanilide, 7.2 to 7.5. For the hydrolysis of the tetrapeptide benzyloxycarbonylglycyl-prolyl-leucyl-glycinamide, the Km value of 75 μ mol l-1 was obtained.

scholarly journals Biosynthesis of proline in Pseudomonas aeruginosa. Partial purification and characterization of γ-glutamyl kinase

1979 ◽  
Vol 181 (1) ◽  
pp. 215-222 ◽  
Author(s):  
R V Krishna ◽  
T Leisinger
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Kinase Activity ◽  
Wild Type Strain ◽  
Deae Cellulose ◽  
Partial Purification ◽  
Purification And Characterization ◽  
Gamma Glutamyl ◽  
Hydrolysis Of ◽  
Molecular Sieving

A gamma-glutamyl kinase (ATP-L-glutamate 5-phosphotransferase) was purified about 85-fold from crude extracts of Pseudomonas aeruginosa strain PAO 1 by (NH4)2SO4 precipitation, molecular-sieving by Sephadex G-150 and DEAE-cellulose chromatography. The molecular weight of this enzyme was 84,000. The preparation catalysed formation of gamma-glutamyl hydroxamate from L-glutamate, ATP and Mg2+ or Mn2+ with concomitant hydrolysis of ATP to ADP + Pi. L-Proline inhibited the gamma-glutamyl kinase activity by 50% at 5 mM and almost completely at 30 mM. The inhibition of L-proline was non-competitive, wherease L-methionine-DL-sulphoximine inhibited the enzyme competitively. Proline was found to inhibit the gamma-glutamyl kinase activity of the wild-type strain and of representatives of two of the three transductional classes of proline-auxotrophic mutants. Strain PAO 879, a mutant representing the third transductional class of proline auxotrophs, lacked proline-inhibitible gamma-glutamyl kinase. Thiol-blocking reagents inhibited the gamma-glutamyl kinase and this effect was prevented by dithiothreitol.

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