Purification and partial characterization of peptidase-1, a sex-linked enzyme inPleurodeles waltl(urodele amphibian)

1997 ◽  
Vol 75 (6) ◽  
pp. 803-806 ◽  
Author(s):  
Etienne Rudolf ◽  
Jean-Michel Girardet ◽  
Anne-Marie Bautz ◽  
Christian Dournon

Peptidase-1 is a sex-linked enzyme, which can be purified from the liver of the amphibian urodele Pleurodeles waltl. We estimated its apparent molecular mass as 170 kDa by gel filtration chromatography. The enzyme is composed of two subunits with apparent molecular masses of 90 and 99 kDa. It is strongly inhibited by ethylenediaminotetraacetic acid, ethylene glycol bis( beta -aminoethyl ether)-N,N-tetraacetic acid, and 1,10-phenanthroline, indicating that peptidase-1 is a metallopeptidase. Peptidase-1 has optimal activity at 55°C and pH 8.5. This acidic enzyme displays two apparent isoelectric points, at 4.9 and 5.2, and is essentially located in the cytosolic subcellular fraction.Key words: peptidase-1, amphibian, purification, characterization, sex-linked enzyme.

1996 ◽  
Vol 42 (6) ◽  
pp. 609-612 ◽  
Author(s):  
Bhagyashree Joshi ◽  
Jayant M. Khire ◽  
Hephzibah SivaRaman ◽  
M. Islam Khan

A lectin was isolated from culture filtrates of Xanthomonas campestris NCIM 5028, by a simple procedure of hydrophobic chromatography on phenyl-Sepharose after ammonium sulphate precipitation. The lectin was a heterodimer, with subunit molecular masses of 30 000 and 28 000. Gel filtration on S-300 column, calibrated with markers, showed its molecular mass to be approximately 70 000. Its isoelectric point was 7.2. The agglutination of the rabbit erythrocytes by the lectin was inhibited by fetuin glycopeptides and host plant (Brassica oleracea) extracts.Key words: Xanthomonas campestris, lectin, purification.


TAPPI Journal ◽  
2013 ◽  
Vol 12 (1) ◽  
pp. 37-43 ◽  
Author(s):  
HANNU PAKKANEN ◽  
TEEMU PALOHEIMO ◽  
RAIMO ALÉN

The influence of various cooking parameters, such as effective alkali, cooking temperature, and cooking time on the formation of high molecular mass lignin-derived and low molecular mass carbohydrates-derived (aliphatic carboxylic acids) degradation products, mainly during the initial phase of softwood kraft pulping was studied. In addition, the mass transfer of all of these degradation products was clarified based on their concentrations in the cooking liquor inside and outside of the chips. The results indicated that the degradation of the major hemicellulose component, galactoglucomannan, typically was dependent on temperature, and the maximum degradation amount was about 60%. In addition, about 60 min at 284°F (140°C) was needed for leveling off the concentrations of the characteristic reaction products (3,4-dideoxy-pentonic and glucoisosaccharinic acids) between these cooking liquors. Compared with low molecular mass aliphatic acids, the mass transfer of soluble lignin fragments with much higher molecular masses was clearly slower.


2005 ◽  
Vol 387 (1) ◽  
pp. 271-280 ◽  
Author(s):  
Seonghun KIM ◽  
Sun Bok LEE

The extremely thermoacidophilic archaeon Sulfolobus solfataricus utilizes D-glucose as a sole carbon and energy source through the non-phosphorylated Entner–Doudoroff pathway. It has been suggested that this micro-organism metabolizes D-gluconate, the oxidized form of D-glucose, to pyruvate and D-glyceraldehyde by using two unique enzymes, D-gluconate dehydratase and 2-keto-3-deoxy-D-gluconate aldolase. In the present study, we report the purification and characterization of D-gluconate dehydratase from S. solfataricus, which catalyses the conversion of D-gluconate into 2-keto-3-deoxy-D-gluconate. D-Gluconate dehydratase was purified 400-fold from extracts of S. solfataricus by ammonium sulphate fractionation and chromatography on DEAE-Sepharose, Q-Sepharose, phenyl-Sepharose and Mono Q. The native protein showed a molecular mass of 350 kDa by gel filtration, whereas SDS/PAGE analysis provided a molecular mass of 44 kDa, indicating that D-gluconate dehydratase is an octameric protein. The enzyme showed maximal activity at temperatures between 80 and 90 °C and pH values between 6.5 and 7.5, and a half-life of 40 min at 100 °C. Bivalent metal ions such as Co2+, Mg2+, Mn2+ and Ni2+ activated, whereas EDTA inhibited the enzyme. A metal analysis of the purified protein revealed the presence of one Co2+ ion per enzyme monomer. Of the 22 aldonic acids tested, only D-gluconate served as a substrate, with Km=0.45 mM and Vmax=0.15 unit/mg of enzyme. From N-terminal sequences of the purified enzyme, it was found that the gene product of SSO3198 in the S. solfataricus genome database corresponded to D-gluconate dehydratase (gnaD). We also found that the D-gluconate dehydratase of S. solfataricus is a phosphoprotein and that its catalytic activity is regulated by a phosphorylation–dephosphorylation mechanism. This is the first report on biochemical and genetic characterization of D-gluconate dehydratase involved in the non-phosphorylated Entner–Doudoroff pathway.


1988 ◽  
Vol 254 (2) ◽  
pp. 419-426 ◽  
Author(s):  
P M Wiest ◽  
E J Tisdale ◽  
W L Roberts ◽  
T L Rosenberry ◽  
A A F Mahmoud ◽  
...  

Biosynthetic labelling experiments with cercariae and schistosomula of the multicellular parasitic trematode Schistosoma mansoni were performed to determine whether [3H]palmitate or [3H]ethanolamine was incorporated into proteins. Parasites incorporated [3H]palmitate into numerous proteins, as judged by SDS/polyacrylamide-gel electrophoresis and fluorography. The radiolabel was resistant to extraction with chloroform, but sensitive to alkaline hydrolysis, indicating the presence of an ester bond. Further investigation of the major 22 kDa [3H]palmitate-labelled species showed that the label could be recovered in a Pronase fragment which bound detergent and had an apparent molecular mass of 1200 Da as determined by gel filtration on Sephadex LH-20. Schistosomula incubated with [3H]ethanolamine for up to 24 h incorporated this precursor into several proteins; labelled Pronase fragments recovered from the three most intensely labelled proteins were hydrophilic and had a molecular mass of approx. 200 Da. Furthermore, reductive methylation of such fragments showed that the [3H]ethanolamine bears a free amino group, indicating the lack of an amide linkage. We also evaluated the effect of phosphatidylinositol-specific phospholipase C from Staphylococcus aureus: [3H]palmitate-labelled proteins of schistosomula and surface-iodinated proteins were resistant to hydrolysis with this enzyme. In conclusion, [3H]palmitate and [3H]ethanolamine are incorporated into distinct proteins of cercariae and schistosomula which do not bear glycophospholipid anchors. The [3H]ethanolamine-labelled proteins represent a novel variety of protein modification.


1999 ◽  
Vol 181 (1) ◽  
pp. 91-99 ◽  
Author(s):  
Hisayo Ono ◽  
Kazuhisa Sawada ◽  
Nonpanga Khunajakr ◽  
Tao Tao ◽  
Mihoko Yamamoto ◽  
...  

ABSTRACT 1,4,5,6-Tetrahydro-2-methyl-4-pyrimidinecarboxylic acid (ectoine) is an excellent osmoprotectant. The biosynthetic pathway of ectoine from aspartic β-semialdehyde (ASA), in Halomonas elongata, was elucidated by purification and characterization of each enzyme involved. 2,4-Diaminobutyrate (DABA) aminotransferase catalyzed reversively the first step of the pathway, conversion of ASA to DABA by transamination with l-glutamate. This enzyme required pyridoxal 5′-phosphate and potassium ions for its activity and stability. The gel filtration estimated an apparent molecular mass of 260 kDa, whereas molecular mass measured by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was 44 kDa. This enzyme exhibited an optimum pH of 8.6 and an optimum temperature of 25°C and had Km s of 9.1 mM forl-glutamate and 4.5 mM for dl-ASA. DABA acetyltransferase catalyzed acetylation of DABA to γ-N-acetyl-α,γ-diaminobutyric acid (ADABA) with acetyl coenzyme A and exhibited an optimum pH of 8.2 and an optimum temperature of 20°C in the presence of 0.4 M NaCl. The molecular mass was 45 kDa by gel filtration. Ectoine synthase catalyzed circularization of ADABA to ectoine and exhibited an optimum pH of 8.5 to 9.0 and an optimum temperature of 15°C in the presence of 0.5 M NaCl. This enzyme had an apparent molecular mass of 19 kDa by SDS-PAGE and a Km of 8.4 mM in the presence of 0.77 M NaCl. DABA acetyltransferase and ectoine synthase were stabilized in the presence of NaCl (>2 M) and DABA (100 mM) at temperatures below 30°C.


1996 ◽  
Vol 319 (3) ◽  
pp. 977-983 ◽  
Author(s):  
Jeong Heon KO ◽  
Cheorl Ho KIM ◽  
Dae-Sil LEE ◽  
Yu Sam KIM

An extremely thermostable ADP-glucose pyrophosphorylase (AGPase) has been purified from Thermus caldophilus GK-24 to homogeneity by chromatographic methods, including gel filtration and ion-exchange and affinity chromatography. The specific activity of the enzyme was enriched 134.8-fold with a recovery of 10.5%. The purified enzyme was a single band by SDS/PAGE with a molecular mass of 52 kDa. The homotetrameric structure of the native enzyme was determined by gel filtration analysis, which showed a molecular mass of 230 kDa on a Superose-12 column, indicating that the structure of the enzyme is different from the heterotetrameric structures of higher-plant AGPases. The enzyme was most active at pH 6.0. The activity was maximal at 73–78 °C and its half-life was 30 min at 95 °C. Kinetic and regulatory properties were characterized. It was found that AGPase activity could be stimulated by a number of glycolytic intermediates. Fructose 6-phosphate, fructose 1,6-bisphosphate, phenylglyoxal and glucose 6-phosphate were effective activators, of which fructose 1,6-bisphosphate was the most effective. The enzyme was inhibited by phosphate, AMP or ADP. ATP and glucose 1-phosphate gave hyperbolic-shaped rate-concentration curves in the presence or absence of activator. A remarkable aspect of the amino acid composition was the existence of the hydrophobic and Ala+Gly residues. The N-terminal and internal peptide sequences were determined and compared with known sequences of various sources. It was apparently similar to those of AGPases from other bacterial and plant sources, suggesting that the enzymes are structurally related.


1994 ◽  
Vol 300 (2) ◽  
pp. 557-565 ◽  
Author(s):  
C Alban ◽  
P Baldet ◽  
R Douce

Young pea leaves contain two structurally different forms of acetyl-CoA carboxylase (EC 6.4.1.2; ACCase). A minor form, which accounted for about 20% of the total ACCase activity in the whole leaf, was detected in the epidermal tissue. This enzyme was soluble and was purified to homogeneity from young pea leaf extracts. It consisted of a dimer of two identical biotinyl subunits of molecular mass 220 kDa. In this respect, this multifunctional enzyme was comparable with that described in other plants and in other eukaryotes. A predominant form was present in both the epidermal and mesophyll tissues. In mesophyll protoplasts, ACCase was detected exclusively in the soluble phase of chloroplasts. This enzyme was partially purified from pea chloroplasts and consisted of a freely dissociating complex, the activity of which may be restored by combination of its separated constituents. The partially purified enzyme was composed of several subunits of molecular masses ranging from 32 to 79 kDa, for a native molecular mass > 600 kDa. One of these subunits, of molecular mass 38 kDa, was biotinylated. This complex subunit structure was comparable with that of microorganisms and was referred to as a ‘prokaryotic’ form of ACCase. Biochemical parameters were determined for both ACCase forms. Finally, both pea leaf ACCases exhibited different sensitivities towards the grass ACCase herbicide, diclofop. This compound had no effect on the ‘prokaryotic’ form of ACCase, while the ‘eukaryotic’ form was strongly inhibited.


2002 ◽  
Vol 22 (16) ◽  
pp. 6000-6013 ◽  
Author(s):  
Steven L. Sanders ◽  
Krassimira A. Garbett ◽  
P. Anthony Weil

ABSTRACT We previously defined Saccharomyces cerevisiae TFIID as a 15-subunit complex comprised of the TATA binding protein (TBP) and 14 distinct TBP-associated factors (TAFs). In this report we give a detailed biochemical characterization of this general transcription factor. We have shown that yeast TFIID efficiently mediates both basal and activator-dependent transcription in vitro and displays TATA box binding activity that is functionally distinct from that of TBP. Analyses of the stoichiometry of TFIID subunits indicated that several TAFs are present at more than 1 copy per TFIID complex. This conclusion was further supported by coimmunoprecipitation experiments with a systematic family of (pseudo)diploid yeast strains that expressed epitope-tagged and untagged alleles of the genes encoding TFIID subunits. Based on these data, we calculated a native molecular mass for monomeric TFIID. Purified TFIID behaved in a fashion consistent with this calculated molecular mass in both gel filtration and rate-zonal sedimentation experiments. Quite surprisingly, although the TAF subunits of TFIID cofractionated as a single complex, TBP did not comigrate with the TAFs during either gel filtration chromatography or rate-zonal sedimentation, suggesting that TBP has the ability to dynamically associate with the TFIID TAFs. The results of direct biochemical exchange experiments confirmed this hypothesis. Together, our results represent a concise molecular characterization of the general transcription factor TFIID from S. cerevisiae.


1994 ◽  
Vol 40 (1) ◽  
pp. 18-23 ◽  
Author(s):  
Andreas Prokop ◽  
Peter Rapp ◽  
Fritz Wagner

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.


1979 ◽  
Vol 183 (2) ◽  
pp. 303-307 ◽  
Author(s):  
K Tryggvason ◽  
K Majamaa ◽  
J Risteli ◽  
K I Kivirikko

Prolyl 3-hydroxylase was purified up to about 5000-fold from an (NH4)2SO4 fraction of chick-embryo extract by a procedure consisting of affinity chromatography on denatured collagen linked to agarose, elution with ethylene glycol and gel filtration. The molecular weight of the purified enzyme is about 160000 by gel filtration The enzyme is probably a glycoprotein, since (a) its activity is inhibited by concanavalin A, and (b) the enzyme is bound to columns of this lectin coupled to agarose and can be eluted with a buffer containing methyl alpha-D-mannoside. The Km values for Fe2+, 2-oxoglutarate, O2 and ascorbate in the prolyl 3-hydroxylase reaction were found to be very similar to those previously reported for these co-substrates in the prolyl 4-hydroxylase and lysyl hydroxylase reactions.


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