The Purification and Properties of an Amidohydrolase from Soybean

1974 ◽  
Vol 52 (10) ◽  
pp. 903-910 ◽  
Author(s):  
Robert E. Hoagland ◽  
George Graf
Keyword(s):  
Arrhenius Plot ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Exchange Chromatography ◽  
Hydrolysis Rate ◽  
Ph Optimum ◽  
Purification And Properties ◽  
Hydrolysis Rates ◽  
Hydrolysis Of

An amidohydrolase (EC 3.5.1.13) was isolated from the roots of soybean (Glycine max Merril, var. Hawkeye) seedlings and purified 130-fold over the crude extract with 30% recovery. The purification steps entailed ammonium sulfate precipitation, gel filtration, cellulose ion-exchange chromatography, and polyacrylamide gel electrophoresis. The specific activity of the purified enzyme for the hydrolysis of Nα-benzoyl-DL-arginine p-nitroanilide (BAPA) was 810 mU/mg. The Km of the enzyme for this substrate was 5.78 × 10−6 M. The enzyme possessed a broad substrate specificity and catalyzed the hydrolysis of BAPA, glycine p-nitroanilide, L-leucine p-nitroanilide, and L-lysine p-nitroanilide. Specificity studies with a series of aminoacyl β-naphthylamides revealed a high hydrolysis rate on Nα-benzoyl-L-arginine β-naphthylamide, and lower hydrolysis rates on several other aminoacyl-substituted β-naphthylamides. The enzyme also displayed dipeptide hydrolase activity on several dipeptide substrates. The enzyme had a pH optimum of 8.0 in 0.05 M phosphate buffer with Nα-benzoyl-DL-arginine p-nitroanilide as substrate. The temperature optimum was 50 °C. The apparent activation energy determined from an Arrhenius plot was 6.3 kcal/mol (26 400 J/mol). The molecular weight estimated by gel filtration was approximately 63 000. Mercury (II) ion, silver (I) ion, p-benzoquinone, p-chloromercuribenzoate, and N-ethylmaleimide were effective inhibitors of the enzyme.

Purification and Properties of a Neutral Protease from Soil Bacterium WM 122

1977 ◽  
Vol 37 (03) ◽  
pp. 556-565 ◽  
Author(s):  
S. E Papaioannou ◽  
W. J Marsheck
Keyword(s):  
Methyl Ester ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
High Specific Activity ◽  
Soil Bacterium ◽  
Ester Hydrochloride ◽  
Apparent Homogeneity ◽  
Purification And Properties ◽  
Hydrolysis Of

SummaryAn extracellular protease SN 687, secreted by the soil bacterium isolate WM 122, has been purified by means of gel filtration, ammonium sulfate precipitation, DEAE-Sephadex and hydroxylapatite chromatography. Apparent homogeneity was ascertained by Polyacrylamide gel electrophoresis. The protease was inactivated by ethylenediamine tetracetic acid (EDTA) but not by diisopropylfluorophosphate (DFP), and it was partially inhibited by serum inhibitors. SN 687 was shown to be of high specific activity against casein and fibrin, but it did not hydrolyze L- lysine -methyl ester dihydrochloride (LME), p-tosyl-L-arginine-methyl ester hydrochloride (TAME) and N-benzoyl-L-tyrosine-ethyl ester hydrochloride (BTEE) synthetic substrates. The optimum pH for hydrolysis of casein was 7.5 and the molecular weight, as determined by gel filtration, was 31,000.

scholarly journals Purification and properties of neutral maltase from human granulocytes

1989 ◽  
Vol 263 (3) ◽  
pp. 647-652 ◽  
Author(s):  
P Delqué Bayer ◽  
C Vittori ◽  
P Sudaka ◽  
J Giudicelli
Keyword(s):  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Human Kidney ◽  
Ph Optimum ◽  
Major Band ◽  
Purification And Properties ◽  
A Minor ◽  
Triton X ◽  
Human Polymorphonuclear Leukocytes

A procedure for the purification of neutral maltase from human polymorphonuclear leukocytes is described, involving solubilization with Triton X-100, proteolytic attack and three chromatographic steps: DEAE ion exchange, AcA 22 gel filtration and a second DEAE chromatography. The enzyme was obtained with a final specific activity of 30 units/mg of protein, comparable with that of other neutral maltases previously purified. The Mr of the enzyme was 550,000 as determined by gel filtration. SDS/polyacrylamide-gel electrophoresis, under non-denaturing conditions, led to a major band of 500,000 and a minor one of 260,000, both active, suggesting a polymeric or aggregated form of the protein. The catalytic properties of the human granulocytic neutral maltase were investigated. The pH optimum was around 6. The enzyme exhibited a broad range of substrate specificity, hydrolysing di- and oligosaccharides with alpha (1→2), alpha (1→3) and alpha (1→4) glucosidic linkages. The highest activities were observed for alpha (1→4) glucose oligomers of three to five residues. It was also found to hydrolyse polysaccharides such as starch and glycogen. The results of the inhibition studies are interpreted in terms of the existence of a large site including several subsites. The enzyme properties are broadly similar to those observed for other purified neutral alpha-glucosidases, in particular that of human kidney origin.

scholarly journals Proteins of the kidney microvillar membrane. Purification and properties of the phosphoramidon-insensitive endopeptidase (‘endopeptidase-2’) from rat kidney

1987 ◽  
Vol 245 (2) ◽  
pp. 515-524 ◽  
Author(s):  
A J Kenny ◽  
J Ingram
Keyword(s):  
Rat Kidney ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Staining Intensity ◽  
Aminopeptidase Activity ◽  
Ph Optimum ◽  
Reducing Conditions ◽  
Purification And Properties ◽  
Relationship Of ◽  
Hydrolysis Of

A second endopeptidase is present in the renal microvillar membrane of rats that can be distinguished from endopeptidase-24.11 by its insensitivity to inhibition by phosphoramidon. The purification of this enzyme, referred to as endopeptidase-2, is described. The enzyme was efficiently released from the membrane by treatment with papain. The subsequent four steps depended on ion-exchange and gel-filtration chromatography. These steps were monitored by the hydrolysis of various substrates: 125I-insulin B chain (the normal assay substrate), benzoyl-L-tyrosyl-p-aminobenzoate (Bz-Tyr-pAB), azocasein and benzyloxycarbonyl-L-phenylalanyl-L-arginine 7-amino-4-methylcoumarylamide (Z-Phe-Arg-NMec). All four assays revealed comparable stepwise increases in activity in the main stages of the purification, although it was apparent that the last-named fluorogenic assay depended on traces of aminopeptidase activity present in the preparation. The Km for 125I-insulin B chain was 16 microM and that for Bz-Tyr-pAB was 4.7 mM. Several experimental approaches confirmed that both peptides were hydrolysed by the same enzyme. The pH optimum was 7.3. Phosphate buffers were inhibitory and shifted the optimum to above pH 9. Zinc was detected in the purified enzyme; EDTA and 1,10-phenanthroline were strongly inhibitory. SDS/polyacrylamide-gel electrophoresis revealed polypeptides of equal staining intensity of Mr 80,000 and 74,000 in reducing conditions. In non-reducing conditions a single band of apparent Mr 220,000 was seen. Gel filtration yielded an Mr of 436,000. These results are consistent with an oligomeric structure in which the alpha and beta chains are linked by disulphide bridges. Endopeptidase-2 hydrolysed a number of neuropeptides. Enkephalins resisted attack, only the heptapeptide [Met]enkephalin-Arg6-Phe7 being susceptible to slow hydrolysis. Luliberin (luteinizing-hormone-releasing hormone) and bradykinin were rapidly hydrolysed. Neurotensin was shown to be slowly attacked at the Tyr3-Glu4 bond. Thus the specificity appears to be limited to the hydrolysis of bonds involving the carboxy group of aromatic residues, provided that this P1 residue is extended by additional residues, at least to the P3′ position. The relationship of this membrane metalloendopeptidase to mouse meprin and human ‘PABA peptidase’ is discussed.

scholarly journals Purification and properties of three (1→3)-β-d-glucanase isoenzymes from young leaves of barley (Hordeum vulgare)

1993 ◽  
Vol 289 (2) ◽  
pp. 453-461 ◽  
Author(s):  
M Hrmova ◽  
G B Fincher
Keyword(s):  
Hordeum Vulgare ◽  
Elevated Temperatures ◽  
Gel Filtration ◽  
Degree Of Polymerization ◽  
Exchange Chromatography ◽  
Purification And Properties ◽  
Young Leaves ◽  
Monomeric Proteins ◽  
Ph Range ◽  
Hydrolysis Of

Three (1->3)-beta-D-glucan glucanohydrolase (EC 3.2.1.39) isoenzymes GI, GII and GIII were purified from young leaves of barley (Hordeum vulgare) using (NH4)2SO4 fractional precipitation, ion-exchange chromatography, chromatofocusing and gel-filtration chromatography. The three (1->3)-beta-D-glucanases are monomeric proteins of apparent M(r)32,000 with pI values in the range 8.8-10.3. N-terminal amino-acid-sequence analyses confirmed that the three isoenzymes represent the products of separate genes. Isoenzymes GI and GII are less stable at elevated temperatures and are active over a narrower pH range than is isoenzyme GIII, which is a glycoprotein containing 20-30 mol of hexose equivalents/mol of enzyme. The preferred substrate for the enzymes is laminarin from the brown alga Laminaria digitata, an essentially linear (1->3)-beta-D-glucan with a low degree of glucosyl substitution at 0-6 and a degree of polymerization of approx. 25. The three enzymes are classified as endohydrolases, because they yield (1->3)-beta-D-oligoglucosides with degrees of polymerization of 3-8 in the initial stages of hydrolysis of laminarin. Kinetic analyses indicate apparent Km values in the range 172-208 microM, kcat. constants of 36-155 s-1 and pH optima of 4.8. Substrate specificity studies show that the three isoenzymes hydrolyse substituted (1->3)-beta-D-glucans with degrees of polymerization of 25-31 and various high-M(r), substituted and side-branched fungal (1->3;1->6)-beta-D-glucans. However, the isoenzymes differ in their rates of hydrolysis of a (1->3;1->6)-beta-D-glucan from baker's yeast and their specific activities against laminarin vary significantly. The enzymes do not hydrolyse (1->3;1->4)-beta-D-glucans, (1->6)-beta-D-glucan, CM-cellulose, insoluble (1->3)-beta-D-glucans or aryl beta-D-glycosides.

scholarly journals Isolation, partial purification and characterization of phospholipase A2 from Naja Katiensis venom

2021 ◽  
Vol 13 (2) ◽  
pp. 107-112
Author(s):  
C.F. Okechukwu ◽  
P.L. Shamsudeen ◽  
R.K. Bala ◽  
B.G. Kurfi ◽  
A.M. Abdulazeez
Keyword(s):  
Ion Exchange ◽  
Phospholipase A2 ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Partial Purification ◽  
Crude Venom

The most effective and acceptable therapy for snakebite victims is the immediate administration of antivenin which is limited by problems of hypersensitivity reactions in some individuals and its inability to resolve the local effects of the venom. The aim of this study was to isolate, partially purify and characterize phospholipase A2 from Naja Katiensis venom. Phospholipase A2 was partially purified via a two-step process: gel filtration on Sephadex G-75 and ion exchange chromatography using CM Sephadex, and subjected to SDS-PAGE analysis. From the results, the specific activity of the partially purified PLA2 decreased from 0.67μmol/min/mg in crude venom to 0.29μmol/min/mg after ion exchange chromatography with a yield of 5% and purification fold of 0.43. The optimum temperature of the purified PLA2 was found to be 35ºC and optimum p.H of 7. velocity studies for the determination of kinetic constants using L-a-lecithin as substrate revealed a Km  of 1.47mg/ml and Vmax  of 3.32μ moles/min/mg. The sodium dodecyl sulphate polyacrylamide gel electrophoresis of the purified PLA2 showed a distinct band with molecular weight estimated to be 14KDa. In conclusion, the present study shows that phospholipase A2 was isolated, purified and characterized. This may serve as a promising candidate for future development of a novel anti-venin drug.

scholarly journals Purification, characterization and inhibition of human skin collagenase

1978 ◽  
Vol 169 (2) ◽  
pp. 265-276 ◽  
Author(s):  
David E. Woolley ◽  
Robert W. Glanville ◽  
Dennis R. Roberts ◽  
John M. Evanson
Keyword(s):  
Human Skin ◽  
Culture Medium ◽  
Serum Proteins ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Polyacrylamide Gel ◽  
Collagen Fibrils ◽  
Ph Optimum

1. The neutral collagenase released into the culture medium by explants of human skin tissue was purified by ultrafiltration and column chromatography. The final enzyme preparation had a specific activity against thermally reconstituted collagen fibrils of 32μg of collagen degraded/min per mg of enzyme protein, representing a 266-fold increase over that of the culture medium. Electrophoresis in polyacrylamide disc gels showed it to migrate as a single protein band from which enzyme activity could be eluted. Chromatographic and polyacrylamide-gel-elution experiments provided no evidence for the existence of more than one active collagenase. 2. The molecular weight of the enzyme estimated from gel filtration and sodium dodecyl sulphate/polyacrylamide-gel electrophoresis was approx. 60000. The purified collagenase, having a pH optimum of 7.5–8.5, did not hydrolyse the synthetic collagen peptide 4-phenylazobenzyloxycarbonyl-Pro-Leu-Gly-Pro-d-Arg-OH and had no non-specific proteinase activity when examined against non-collagenous proteins. 3. It attacked undenatured collagen in solution at 25°C, producing the two characteristic products TCA(¾) and TCB(¼). Collagen types I, II and III were all cleaved in a similar manner by the enzyme at 25°C, but under similar conditions basement-membrane collagen appeared not to be susceptible to collagenase attack. At 37°C the enzyme attacked gelatin, producing initially three-quarter and one-quarter fragments of the α-chains, which were degraded further at a lower rate. As judged by the release of soluble hydroxyproline peptides and electron microscopy, the purified enzyme degraded insoluble collagen derived from human skin at 37°C, but at a rate much lower than that for reconstituted collagen fibrils. 4. Inhibition of the skin collagenase was obtained with EDTA, 1,10-phenanthroline, cysteine, dithiothreitol and sodium aurothiomaleate. Cartilage proteoglycans did not inhibit the enzyme. The serum proteins α2-macroglobulin and β1-anti-collagenase both inhibited the enzyme, but α1-anti-trypsin did not. 5. The physicochemical and enzymic properties of the skin enzyme are discussed in relation to those of other human collagenases.

scholarly journals Carbonic anhydrase isoenzymes in the erthrocytes and dorsolateral prostate of the rat

1969 ◽  
Vol 114 (3) ◽  
pp. 463-476 ◽  
Author(s):  
J. E. A. McIntosh
Keyword(s):  
Carbonic Anhydrase ◽  
High Activity ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Exchange Chromatography ◽  
Kinetic Properties ◽  
Efficient Catalyst ◽  
Molecular Weights ◽  
Hydrolysis Of ◽  
Low Activity

1. Three forms of the zinc-containing enzyme carbonic anhydrase (EC 4.2.1.1) were isolated from the erythrocytes of the rat and two forms from the dorsolateral prostate of the rat. Several additional minor components were observed but not isolated. Separation of the isoenzymes was achieved by ion-exchange chromatography, polyacrylamide-gel electrophoresis and isoelectric focusing. 2. The general properties of the isolated isoenzymes, their molecular weights and their contents of zinc were closely similar. As catalysts of the hydration of carbon dioxide, however, they were distinctly different. The two most abundant isoenzymes of the erythrocytes, which were found in equal proportions, differed 70-fold in specific activity, whereas the isoenzymes of the dorsolateral prostate were similar to one another and resembled the high-activity component of the erythrocytes. The inhibition of the latter by acetazolamide (5-acetamido-1-thia-3,4-diazole-2-sulphonamide) was mainly competitive, whereas in identical conditions the low-activity erythrocyte component and the dorsolateral prostate isoenzymes were non-competitively inhibited. 3. The use of chloroform–ethanol to remove haemoglobin from the rat haemolysate was found (a) to bring about changes in the kinetic properties of the soluble isoenzymes and (b) to cause the appearance of an additional isoenzyme. 4. The actions were compared of the inhibitors acetazolamide, 1,1-dimethylaminonaphthalene-5-sulphonamide and ethoxzolamide (6-ethoxybenzothiazole-2-sulphonamide) on the hydrolysis of p-nitrophenyl acetate catalysed by the isoenzymes. 5. The low-activity erythrocyte isoenzyme was an efficient catalyst of the hydrolysis of β-naphthyl acetate whereas the high-activity forms were much less active towards this ester. Neither of the isoenzymes present in the dorsolateral prostate catalysed this reaction. 6. Carbonic anhydrase in the rat dorsolateral prostate accounts for no more than 5% of the unusually high content of zinc in this organ.

Purification and characterization of the extracellular α-amylase activity of the yeast Schwanniomyces alluvius

1987 ◽  
Vol 65 (10) ◽  
pp. 899-908 ◽  
Author(s):  
F. Moranelli ◽  
M. Yaguchi ◽  
G. B. Calleja ◽  
A. Nasim
Keyword(s):  
Amino Acid ◽  
Amylase Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Deae Cellulose ◽  
Exchange Chromatography ◽  
Proteinase K ◽  
Ph Optimum ◽  
Sds Page

The extracellular α-amylase activity of the yeast Schwanniomyces alluvius has been purified by anion-exchange chromatography on DEAE-cellulose and gel-filtration chromatography on Sephadex G-100. Sodium dodecyl sulfate – polyacrylamide gel electrophoresis (SDS–PAGE) and N-terminal amino acid analysis of the purified sample indicated that the enzyme preparation was homogeneous. The enzyme is a glycoprotein having a molecular mass of 52 kilodaltons (kDa) estimated by SDS–PAGE and 39 kDa by gel filtration on Sephadex G-100. Chromatofocusing shows that it is an acidic protein. It is resistant to trypsin but sensitive to proteinase K. Its activity is inhibited by the divalent cation chelators EDTA and EGTA and it is insensitive to sulfhydryl-blocking agents. Exogenous divalent cations are inhibitory as are high concentrations of monovalent salts. The enzyme has a pH optimum between 3.75 and 5.5 and displays maximum stability in the pH range of 4.0–7.0. Under the conditions tested, the activity is maximal between 45 and 50 °C and is very thermolabile. Analysis of its amino acid composition supports its acidic nature.

scholarly journals Purification and properties of l-mandelate dehydrogenase and comparison with other membrane-bound dehydrogenases from Acinetobacter calcoaceticus

1987 ◽  
Vol 248 (3) ◽  
pp. 871-876 ◽  
Author(s):  
M E Hoey ◽  
N Allison ◽  
A J Scott ◽  
C A Fewson
Keyword(s):  
Lactate Dehydrogenase ◽  
Ion Exchange ◽  
Gel Filtration ◽  
Acinetobacter Calcoaceticus ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Ph Optimum ◽  
Purification And Properties ◽  
Potential Inhibitors ◽  
Triton X

L-Mandelate dehydrogenase was purified from Acinetobacter calcoaceticus by Triton X-100 extraction from a ‘wall + membrane’ fraction, ion-exchange chromatography on DEAE-Sephacel, (NH4)2SO4 fractionation and gel filtration followed by further ion-exchange chromatography. The purified enzyme was partially characterized with respect to its subunit Mr (44,000), pH optimum (7.5), pI value (4.2), substrate specificity and susceptibility to various potential inhibitors including thiol-blocking reagents. FMN was identified as the non-covalently bound cofactor. The properties of L-mandelate dehydrogenase are compared with those of D-mandelate dehydrogenase, D-lactate dehydrogenase and L-lactate dehydrogenase from A. calcoaceticus.

scholarly journals Purification and properties of 6-phosphogluconate dehydrogenase from rabbit mammary gland

1975 ◽  
Vol 151 (2) ◽  
pp. 263-270 ◽  
Author(s):  
S A Betts ◽  
R J Mayer
Keyword(s):  
Molecular Weight ◽  
Mammary Gland ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Phosphogluconate Dehydrogenase ◽  
Purification And Properties ◽  
Competitive Inhibitors ◽  
Final Purification Step

1. 6-Phosphogluconate dehydrogenase from rabbit mammary gland was purified to homogeneity by the criterion of polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate. The molecular weight of the subunit is 52 000. The enzyme was purified 150-fold with a final specific activity of 20 mumol of NADP+ reduced/min per mg of protein and overall yield of 3%. The molecular weight of the native enzyme is estimated to be 104 000 from gel-filtration studies. The final purification step was carried out by affinity chromatography with NADP+-Sepharose. 2. The Km values for 6-phosphogluconate and NADP+ are approx. 54 muM and 23 muM respectively. 3. Citrate and pyrophosphate are competitive inhibitors of the enzyme with respect to both 6-phosphogluconate and NADP+. 4. MgCl2 affects the apparent Km for NADP+ at saturating concentrations of 6-phosphogluconate.

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