The purification and characterization of a β-glucosidase from Alcaligenes faecalis

1986 ◽  
Vol 64 (9) ◽  
pp. 914-922 ◽  
Author(s):  
Anthony G. Day ◽  
Stephen G. Withers
Keyword(s):  
Glucose Production ◽  
High Specificity ◽  
Alcaligenes Faecalis ◽  
Divalent Metal ◽  
Exchange Chromatography ◽  
Good Choice ◽  
Divalent Metal Ions ◽  
Purification And Characterization ◽  
Glucanase Activity

The β-glucosidase from Alcaligenes faecalis has been purified to homogeneity (880-fold purification, 11% yield) using a combination of classical techniques and medium pressure ion-exchange chromatography. It is a dimeric enzyme of monomer molecular weight 50 000 and has no specific requirement for divalent metal ions. It has a high specificity for β-glucosides and hydrolyses a wide variety of different chemical types with retention of configuration at the anomeric centre. It has no exo-β-1,4-glucanase activity. It is reversibly inhibited by a variety of sugars which have been shown previously to be very active against glucosidases, suggesting a normal mechanism of action. Measured Km values for cellobiose and p-nitrophenyl β-D-glucopyranoside are quite low (0.70 and 0.08 mM, respectively), making this a good choice for cocloning into a cellulase system optimized for glucose production.

Purification and Characterization of Three Extracellular Proteinases Produced by Pseudomonas fluorescens INIA 745, an Isolate from Ewe's Milk

1999 ◽  
Vol 62 (5) ◽  
pp. 543-546 ◽  
Author(s):  
J. FERNÁNDEZ ◽  
A. F. MOHEDANO ◽  
P. GAYA ◽  
M. MEDINA ◽  
M. NUÑEZ
Keyword(s):  
Pseudomonas Fluorescens ◽  
Culture Medium ◽  
Inhibitory Effect ◽  
Divalent Metal ◽  
Divalent Metal Ions ◽  
Purification And Characterization ◽  
Ph Optimum ◽  
Extracellular Proteinases ◽  
Ewe's Milk

Three proteinases were isolated from culture medium of Pseudomonas fluorescens INIA 745 and purified to homogeneity by a combination of Phenyl-Sepharose, DEAE-Sepharose, and Sephadex G-100 chromatography. Optimal temperature for enzymatic activity was 45°C for all three proteinases. The pH optimum of proteinases I and II was found to be 7.0, while that of proteinase III was 8.0. Divalent metal ions like Cu2+, Co2+, Zn2+, Fe2+, and Hg2+ were inhibitory to proteinase activity while Ca2+, Mg2+, and Mn2+ had little or no inhibitory effect. The three enzymes were strongly inhibited by EDTA and 1,10-phenantroline and partially by cysteine. The three enzymes are metalloproteinases since they were inhibited by chelators and reactivated by Co2+, Mn2+, Cu2+, and Zn2+. The Km values of proteinases I, II, and III for casein were calculated to be 3.2, 2.6, and 5.2 mg/ml, respectively. Proteinases II and III rapidly degraded β-casein, with preference to αs1-casein, whereas proteinase I hydrolyzed both casein fractions at a slow rate.

Extracellular nucleases of Lysobacter enzymogenes: purification and characterization of a ribonuclease

1981 ◽  
Vol 27 (10) ◽  
pp. 1080-1086 ◽  
Author(s):  
R. G. vonTigerstrom
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Polypeptide Chain ◽  
Maximum Activity ◽  
Divalent Metal ◽  
Divalent Metal Ions ◽  
Purification And Characterization ◽  
Lysobacter Enzymogenes ◽  
Base Specificity

The ribonuclease of Lysobacter enzymogenes is one of two major extracellular nucleolytic enzymes produced by the organism. The enzyme was purified 560-fold and appeared to be free of contaminating proteins and interfering enzymes. The Lysobacter RNAase consists of one polypeptide chain with a molecular weight of 46 000 – 47 000. The enzyme was most active at pH 8.0–8.5 and in the presence of Mg2+. Approximately 45% of the maximum activity was obtained in the presence of Ca2+, whereas little or no activity was obtained in the presence of Mn2+ or without divalent metal ions. RNA, poly(A), and poly(C) served as substrates but DNA was not hydrolysed. High molecular weight RNA was degraded by the RNAase to short oligonucleotides with 5′-phosphate ends and there was no apparent base specificity.

scholarly journals UDP-glucose:solasodine glucosyltransferase from eggplant (Solanum melongena L.) leaves: partial purification and characterization.

1997 ◽  
Vol 44 (1) ◽  
pp. 43-53 ◽  
Author(s):  
C Paczkowski ◽  
M Kalinowska ◽  
Z A Wojciechowski
Keyword(s):  
Molecular Mass ◽  
Solanum Melongena ◽  
Divalent Metal ◽  
Partial Purification ◽  
Divalent Metal Ions ◽  
Purification And Characterization ◽  
Ph Optimum ◽  
Cytosol Fraction ◽  
Ammonium Sulphate Precipitation ◽  
Unripe Fruits

Uridine 5'-diphosphoglucose-dependent glucosyltransferase which catalyzes the glycosylation of solasodine i.e. UDP-glucose:solasodine glucosyltransferase, is present in leaves, roots, unripe fruits and unripe seeds of eggplant (Solanum melongena L.). The glucosylation product is chromatographically identical with authentic solasodine 3 beta-D-monoglucoside, a putative intermediate in the biosynthesis of solasodine-based glycoalkaloids characteristic of the eggplant. The enzyme was purified about 50-fold from crude cytosol fraction of eggplant leaves by ammonium sulphate precipitation and column chromatography on Q-Sepharose and Sephadex G-100. The native enzyme has a molecular mass of approx. 55 kDa and pH optimum of 8.5. Divalent metal ions are not required for its activity but the presence of free-SH groups is essential. Besides solasodine (Km = 0.04 microM), the enzyme effectively glucosylates tomatidine, another steroidal alkaloid of the spirosolane type, but it is virtually inactive towards the solanidane-type steroidal alkaloids such as solanidine or demissidine. The enzyme is specific for UDP-glucose (Km = 2.1 microM) since unlabelled ADP-, GDP-, CDP- or TDP-glucose could not effectively compete with UDP-[14C]glucose used as the sugar donor for solasodine glucosylation. Moreover, no synthesis of labelled solasodine galactoside was observed when UDP-[14C]glucose was replaced with UDP-[14C]galactose.

scholarly journals Purification and Characterization of Endoglucanase from local isolate of Aspergillus flavus

2013 ◽  
Vol 10 (3) ◽  
pp. 844-853
Author(s):  
Baghdad Science Journal
Keyword(s):  
Aspergillus Flavus ◽  
Specific Activity ◽  
Gel Filtration ◽  
Temperature Stability ◽  
Exchange Chromatography ◽  
Purification And Characterization ◽  
Original Activity ◽  
A Value ◽  
Optimum Ph

Endoglucanase produced from Aspergillus flavus was purified by several steps including precipitation with 25 % ammonium sulphate followed by Ion –exchange chromatography, the obtained specific activity was 377.35 U/ mg protein, with a yield of 51.32 % .This step was followed by gel filtration chromatography (Sepharose -6B), when a value of specific activity was 400 U/ mg protein, with a yield of 48 %. Certain properties of this purified enzyme were investigated, the optimum pH of activity was 7 and the pH of its stability was 4.5, while the temperature stability was 40 °C for 60 min. The enzyme retained 100% of its original activity after incubation at 40 °C for 60 min; the optimum temperature for enzyme activity was 40 °C.

scholarly journals Purification and characterization of human neuropeptide Y from adrenal-medullary phaeochromocytoma tissue

1984 ◽  
Vol 219 (3) ◽  
pp. 699-706 ◽  
Author(s):  
R Corder ◽  
P C Emson ◽  
P J Lowry
Keyword(s):  
Amino Acid ◽  
Neuropeptide Y ◽  
Amino Acid Analysis ◽  
Gel Filtration ◽  
Exchange Chromatography ◽  
Carboxypeptidase Y ◽  
Purification And Characterization ◽  
Reverse Phase ◽  
Tryptic Fragment

Human neuropeptide Y was isolated from acid extracts of adrenal-medullary phaeochromocytoma tissue. After (NH4)2SO4 fractionation, the neuropeptide Y-like immunoreactivity was purified from the resolubilized 80%-saturation-(NH4)2SO4 peptide-rich precipitate, by gel filtration, cation-exchange chromatography and reverse-phase high-pressure liquid chromatography. Amino acid analysis of the peptide revealed a composition almost identical with that of the pig peptide, the exception being the loss of one leucine residue and its replacement with methionine. Tryptic digestion of the peptide and subsequent amino acid analysis of the fragments further confirmed the identity of the peptide. Carboxypeptidase Y digestion of the (1-19)-peptide tryptic fragment has shown the methionine to be located at position 17 in human neuropeptide Y.

Production, purification, and characterization of an extracellular endo-β-1, 3-glucanase from a monokaryon of Schizophyllum commune ATCC 38548 defective in exo-β-1, 3-glucanase formation

1994 ◽  
Vol 40 (1) ◽  
pp. 18-23 ◽  
Author(s):  
Andreas Prokop ◽  
Peter Rapp ◽  
Fritz Wagner
Keyword(s):  
Molecular Mass ◽  
Schizophyllum Commune ◽  
Gel Filtration ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Glucanase Activity ◽  
Sds Page ◽  
S 100 ◽  
Reduced Activity

Production of extracellular β-1, 3-glucanase activity by a monokaryotic Schizophyllum commune strain was monitored and results indicated that the β-glucanase activity consisted of an endo- β-1, 3-glucanase activity, besides a negligible amount of β-1, 6-glucanase and β-glucosidase activity. Unlike the β-1, 3-glucanase production of the dikaryotic parent strain S. commune ATCC 38548, the β-1, 3-glucanase formation of the monokaryon was not regulated by catabolite repression. The endo- β-1, 3-glucanase of the monokaryon was purified from the culture filtrate by lyophilization, anion exchange chromatography on Mono Q, and gel filtration on Sephacryl S-100. It appeared homogeneous on SDS-PAGE with a molecular mass of 35.5 kDa and the isoelectric point was 3.95. The enzyme was only active toward glucans containing β-1, 3-linkages, including lichenan, a β-1, 3-1, 4-D-glucan. It attacked laminarin in an endo-like fashion to form laminaribiose, laminaritriose, and high oligosaccharides. While the extracellular β-glucanases from the dikaryotic S. commune ATCC 38548 degraded significant amounts of schizophyllan, the endo- β-1, 3-glucanase from the monokaryon showed greatly reduced activity toward this high molecular mass β-1, 3-/β-1, 6-glucan. The Km of the endoglucanase, using laminarin as substrate, was 0.28 mg/mL. Optimal pH and temperature were 5.5 and 50 °C, respectively. The enzyme was stable between pH 5.5 and 7.0 and at temperatures below 50 °C. The enzyme was completely inhibited by 1 mM Hg2+. Growth of the monokaryotic S. commune strain was not affected by its constitutive endo- β-1, 3-glucanase formation.Key words: endo- β-1, 3-glucanase, Schizophyllum commune, monokaryon, constitutive endo- β-1, 3-glucanase formation.

scholarly journals Purification and characterization of the heat-stable serine proteinase from Thermomonospora fusca YX

1987 ◽  
Vol 246 (2) ◽  
pp. 511-517 ◽  
Author(s):  
T W Gusek ◽  
J E Kinsella
Keyword(s):  
Thermal Stability ◽  
Ionic Strength ◽  
Serine Proteinase ◽  
Maximum Activity ◽  
Exchange Chromatography ◽  
Cation Exchange Chromatography ◽  
Purification And Characterization ◽  
Thermomonospora Fusca ◽  
Heat Stable

The proteinase secreted from Thermomonospora fusca YX grown on cellulose was purified by (NH4)2SO4 fractionation and cation-exchange chromatography. The isolated proteinase readily hydrolysed several proteins and demonstrated activity towards casein from 35 to 95 degrees C (at pH 8.0) with maximum activity at 80 degrees C. It exhibited broad pH and ionic-strength optima centered at pH 9.0 and 0.2 M-NaCl respectively, and it retained high activity in the presence of 2% (w/v) SDS, 20 mM-dithiothreitol and 1.0 M-NaCl. The proteinase, which was fully inhibited by phenylmethanesulphonyl fluoride, had an Mr of 14,500 and an isoelectric point at 9.21. A measurement of proteinase thermal stability demonstrated a T50% (15 min) of 85 degrees C at pH 4.5.

Overproduction, purification and characterization of FtmPT1, a brevianamide F prenyltransferase from Aspergillus fumigatus

Microbiology ◽  
2005 ◽  
Vol 151 (7) ◽  
pp. 2199-2207 ◽  
Author(s):  
Alexander Grundmann ◽  
Shu-Ming Li
Keyword(s):  
Aspergillus Fumigatus ◽  
Enzymic Activity ◽  
Divalent Metal Ions ◽  
Purification And Characterization ◽  
Turnover Number ◽  
Dimethylallyl Diphosphate ◽  
Dimethylallyltryptophan Synthase ◽  
Aromatic Substrates ◽  
Prenyl Diphosphate

A putative prenyltransferase gene, ftmPT1, was identified in the genome sequence of Aspergillus fumigatus. ftmPT1 was cloned and expressed in Escherichia coli, and the protein FtmPT1 was purified to near homogeneity and characterized biochemically. This enzyme was found to catalyse the prenylation of cyclo-l-trp-l-Pro (brevianamide F) at the C-2 position of the indole nucleus. FtmPT1 is a soluble monomeric protein, which does not contain the usual prenyl diphosphate binding site (N/D)DXXD found in most prenyltransferases, and which does not require divalent metal ions for its enzymic activity. K m values for brevianamide F and dimethylallyl diphosphate were determined as 55 and 74 μM, respectively. The turnover number was 5·57 s−1. FtmPT1 showed a high substrate specificity towards dimethylallyl diphosphate, but accepted different tryptophan-containing cyclic dipeptides. Together with dimethylallyltryptophan synthase of ergot alkaloid biosynthesis, FtmPT1 belongs to a new group of prenyltransferases with aromatic substrates.

Sign in / Sign up

Export Citation Format

Share Document