Characterization of the esterases of canine serum

1970 ◽  
Vol 48 (12) ◽  
pp. 1359-1367 ◽  
Author(s):  
D. J. Ecobichon

Various techniques including electrophoresis, gel filtration, and titrimetric and spectrophotometric analysis with specific and nonspecific substrates and inhibitors were used to characterize the serum esterases of male and female dogs. Electrophoresis in starch gel yielded 10 distinct bands of activity: four butyrylcholinesterase bands, an esterolytically active albumin, and five bands of aliesterase and/or arylesterase activity. Gel filtration on Sephadex G-200 yielded two distinct peaks of activity, one containing the cholinesterase bands, and the second peak containing both arylesterase and aliesterase activity in close association with the serum albumin. Kinetic characteristics determined for the canine serum esterases included (1) optimal pH; (2) Km values for esters of choline, α-naphthol, and p-nitrophenol; and (3) average rates of hydrolysis of α-naphthyl acetate, butyrylcholine iodide, p-nitrophenyl acetate, and E600 by the sera of males and females. The sensitivity of the serum esterases to inhibition by various cations, and specific and nonspecific inhibitors was investigated. The organophosphate, E600, may be a highly specific substrate for the detection and quantification of arylesterase in a mixture of nonspecific carboxylesterases.

1974 ◽  
Vol 52 (11) ◽  
pp. 1073-1078 ◽  
Author(s):  
D. J. Ecobichon

Various techniques, including electrophoresis, gel filtration, titrimetric, and spectrophotometric analysis with specific and nonspecific substrates and inhibitors, were used to characterize the serum esterases of male and female cats. Starch-gel electrophoresis yielded five bands of activity: three butyrylcholinesterase bands and two bands of nonspecific carboxylesterase activity. Gel filtration on Sephadex G-200 yielded two distinct peaks of activity, one containing the cholinesterase bands and the other, the carboxylesterase activity. Kinetic characteristics determined for feline serum esterases included: (1) optimal pH; (2) optimal substrates for cholinesterase and carboxylesterase activities; (3) Km values for the choline, α-naphthyl, and p-nitrophenyl esters. With the organophosphate paraoxon as a specific substrate for arylesterase activity, low levels of this enzyme could be detected in close association with the carboxylesterase.


2000 ◽  
Vol 66 (1) ◽  
pp. 252-256 ◽  
Author(s):  
Katsuichi Saito ◽  
Kazuya Kondo ◽  
Ichiro Kojima ◽  
Atsushi Yokota ◽  
Fusao Tomita

ABSTRACT Streptomyces exfoliatus F3-2 produced an extracellular enzyme that converted levan, a β-2,6-linked fructan, into levanbiose. The enzyme was purified 50-fold from culture supernatant to give a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The molecular weights of this enzyme were 54,000 by SDS-PAGE and 60,000 by gel filtration, suggesting the monomeric structure of the enzyme. The isoelectric point of the enzyme was determined to be 4.7. The optimal pH and temperature of the enzyme for levan degradation were pH 5.5 and 60°C, respectively. The enzyme was stable in the pH range 3.5 to 8.0 and also up to 50°C. The enzyme gave levanbiose as a major degradation product from levan in an exo-acting manner. It was also found that this enzyme catalyzed hydrolysis of such fructooligosaccharides as 1-kestose, nystose, and 1-fructosylnystose by liberating fructose. Thus, this enzyme appeared to hydrolyze not only β-2,6-linkage of levan, but also β-2,1-linkage of fructooligosaccharides. From these data, the enzyme from S. exfoliatus F3-2 was identified as a novel 2,6-β-d-fructan 6-levanbiohydrolase (EC 3.2.1.64 ).


1998 ◽  
Vol 64 (2) ◽  
pp. 789-792 ◽  
Author(s):  
Giuliano Degrassi ◽  
Benedict C. Okeke ◽  
Carlo V. Bruschi ◽  
Vittorio Venturi

ABSTRACT Bacillus pumilus PS213 was found to be able to release acetate from acetylated xylan. The enzyme catalyzing this reaction has been purified to homogeneity and characterized. The enzyme was secreted, and its production was induced by corncob powder and xylan. Its molecular mass, as determined by gel filtration, is 190 kDa, while sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed a single band of 40 kDa. The isoelectric point was found to be 4.8, and the enzyme activity was optimal at 55°C and pH 8.0. The activity was inhibited by most of the metal ions, while no enhancement was observed. The Michaelis constant (Km ) andV max for α-naphthyl acetate were 1.54 mM and 360 μmol min−1 mg of protein−1, respectively.


1987 ◽  
Vol 73 (1) ◽  
pp. 19-28 ◽  
Author(s):  
H. M. Morrison ◽  
J. A. Kramps ◽  
S. C. Afford ◽  
D. Burnett ◽  
J. H. Dijkman ◽  
...  

1. Anti-elastase function in sputum sol-phase from patients with α1-proteinase inhibitor (α1PI) deficiency was compared with sol-phase from patients with cigarette smoke-induced bronchitis and emphysema. 2. Both α1PI (2P < 0.01) and anti-leucoprotease (ALP) (2P < 0.01) concentrations were lower in sol-phase from the α1PI-deficient group, although α2-macroglobulin (α2M) levels were similar. 3. There was no difference in α1PI function between the two groups, but the inhibitor was only ≃ 30% active. 4. The absolute neutrophil elastase (NE) inhibitory capacity was similar in both groups (median 185 μg of NE inhibited/ml of sputum, range 80–480, for the α1PI-deficient group; median 175, range 80–300, for the bronchitic group). A substantial proportion of NE inhibition in secretions could not be accounted for by the amount of α1PI, ALP and α2M present (median 74.8%, range 43.2–97.4, for α1PI-deficient sol-phase; median 50.0%, range 0–80.8, for bronchitic sol-phase). 5. Gel filtration of sol-phase demonstrated the presence of NE inhibition in the low molecular weight fractions which was markedly sensitive to changes in substrate concentration and ionic strength, in contrast to purified α1PI and ALP. 6. Sputum sol-phase from both groups failed to prevent hydrolysis of elastin–fluorescein or succinyltrialanyl-p-nitroanilide by NE completely during prolonged incubation in the presence of an excess of functional inhibitors. This was more apparent in secretions from subjects with α1PI deficiency and may explain why such patients have a more rapidly progressive form of emphysema.


1979 ◽  
Vol 177 (1) ◽  
pp. 107-114 ◽  
Author(s):  
T G Villa ◽  
V Notario ◽  
J R Villanueva

The endo-1,3-beta-glucanase (EC 3.2.1.6) secreted into the culture medium by cells of Candida utilis was isolated and purified to homogeneity on polyacrylamide-gel electrophoresis and in ultracentrifugation studies (s20,w = 1.97S). The purified enzyme represented only 0.001% of the total 1,3-beta-glucanase activity, the remainder being due to an exo-1,3-beta-glucanase enzyme, and behaved as an acidic glycoprotein (pI 3.3) in isoelectric-focusing experiments. The mol.wt. was estimated to be 21 000 by gel filtration and polyacrylamide-gel electrophoresis. Studies on the hydrolysis of different substrates showed that the enzyme was only able to break down (1 leads to 3)-beta-linkages, by an endo-splitting mechanism. Glucono-delta-lactone, D-glucoronolactone and heavy metal ions such as Hg2+ were inhibitors of the enzyme activity. The function of this endo-beta-glucanase in C. utilis is discussed.


1996 ◽  
Vol 316 (3) ◽  
pp. 841-846 ◽  
Author(s):  
Stuart M. PITSON ◽  
Robert J. SEVIOUR ◽  
Barbara M. McDOUGALL ◽  
Bruce A. STONE ◽  
Maruse SADEK

An endo-(1 → 6)-β-glucanase has been isolated from the culture filtrates of the filamentous fungus Acremonium persicinum and purified by (NH4)2SO4 precipitation followed by anion-exchange and gel-filtration chromatography. SDS/PAGE of the purified enzyme gave a single band with an apparent molecular mass of 42.7 kDa. The enzyme is a non-glycosylated, monomeric protein with a pI of 4.9 and pH optimum of 5.0. It hydrolysed (1 → 6)-β-glucans (pustulan and lutean), initially yielding a series of (1 → 6)-β-linked oligoglucosides, consistent with endo-hydrolytic action. Final hydrolysis products from these substrates were gentiobiose and gentiotriose, with all products released as β-anomers, indicating that the enzyme acts with retention of configuration. The purified enzyme also hydrolysed Eisenia bicyclis laminarin, liberating glucose, gentiobiose, and a range of larger oligoglucosides, through the apparent hydrolysis of (1 → 6)-β- and some (1 → 3)-β-linkages in this substrate. Km values for pustulan, lutean and laminarin were 1.28, 1.38, and 1.67 mg/ml respectively. The enzyme was inhibited by N-acetylimidazole, N-bromosuccinimide, dicyclohexylcarbodi-imide, Woodward's Regent K, 2-hydroxy-5-nitrobenzyl bromide, KMnO4 and some metal ions, whereas D-glucono-1,5-lactone and EDTA had no effect.


1973 ◽  
Vol 51 (5) ◽  
pp. 506-513 ◽  
Author(s):  
D. J. Ecobichon

The esterases of canine liver and kidney were separated electrophoretically into nine bands with identical migration patterns in both tissues. An additional pair of rapidly migrating anodic bands were observed in hepatic extracts. Based on substrate specificity, the predominant tissue esterases were identified as nonspecific carboxylesterases (aliesterases). No cholinesterase activity was detected in the tissue extracts. Kinetic characteristics determined for the hepatic and renal esterases included (1) optimal pH; (2) Km values for esters of α-naphthyl and p-nitrophenol; (3) average rates of hydrolysis of α-naphthyl acetate and p-nitrophenyl acetate by the tissue extracts. Inhibition studies revealed the presence of two types of esterase activity in each tissue: one type being sensitive to organophosphorus esters, the second being resistant. A study of preferential substrate hydrolysis in the presence of known characteristic activators and inhibitors of esterases revealed approximately 5% and 20% arylesterase activity in liver and kidney, respectively. The presence of arylesterase activity in these tissues was confirmed by the hydrolysis of paraoxon (E600).


1984 ◽  
Vol 219 (2) ◽  
pp. 437-444 ◽  
Author(s):  
N E Mackenzie ◽  
J P Malthouse ◽  
A I Scott

The kinetics of the trypsin-catalysed hydrolysis of the highly specific substrate N alpha-benzyloxycarbonyl-L-lysine p-nitrophenyl ester were studied under cryoenzymological conditions by 13C-n.m.r. spectroscopy at pH approx. 3.0. The kinetics of this reaction are shown to be in agreement with similar studies made with the use of u.v.-visible-absorption-spectrophotometric techniques. A combination of 13C-n.m.r. spectroscopy and cryoenzymology has for the first time detected an acyl-trypsin intermediate in the hydrolysis of this highly specific substrate. The advantages and difficulties of using 13C-n.m.r. spectroscopy coupled with cryoenzymology in the detection and characterization of enzyme-substrate intermediates are discussed.


1982 ◽  
Vol 47 (4) ◽  
pp. 1139-1148 ◽  
Author(s):  
Karel Hauzer ◽  
Linda Servítová ◽  
Tomislav Barth ◽  
Karel Jošt

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.


2017 ◽  
Vol 37 (1) ◽  
pp. 31
Author(s):  
Fitria Fitria ◽  
Nanik Rahmani ◽  
Sri Pujiyanto ◽  
Budi Raharjo ◽  
Yopi Yopi

Enzyme xylanase (EC 3.2.1.8) is widely used in various industrial  fields for the hydrolysis of xylan (hemicellulose) into xylooligosaccharide and xylose. The aims of this study were to  conduct partial purification and characterization of xylanase from marine Bacillus safencis strain LBF P20 and to obtain the  xylooligosaccharide types from xylan hydrolysis by this enzyme.  Based on this research, the optimum time for enzyme production  occurred at 96 hours with the enzyme activity of 6.275 U/mL and  enzyme specific activity of 5.093 U/mg. The specific activities were  obtained from precipitation by amicon® ultra-15 centrifugal filter devices, gel filtration chromatography and anion exchange chromatography that were increased by 15.07, 34.7, and 96.0  U/mg. The results showed that the highest activity at pH 7, temperature of 60 °C, and stable at 4 °C. Type of  xylooligosaccharide produced by this study were xylohexoses, xylotriose, and xylobiose. SDS-PAGE analysis and zimogram  showed that the molecular weight of xylanase protein were about  25 kDa. ABSTRAKEnzim xilanase (EC 3.2.1.8) digunakan dalam hidrolisis xilan  (hemiselulosa) menjadi xilooligosakarida dan xilosa. Penelitian  ini bertujuan untuk melakukan purifikasi parsial dan karakterisasi xilanase dari bakteri laut Bacillus safencis strain LBF P20 serta uji  hidrolisis untuk mengetahui jenis xilooligosakarida yang  dihasilkan oleh enzim tersebut. Berdasarkan hasil penelitian, waktu optimum untuk produksi enzim terjadi pada jam ke 96  dengan aktivitas enzim sebesar 6,275 U/mL dan aktivitas spesifik enzim sebesar 5,093 (U/mg). Aktivitas spesifik enzim hasil  pemekatan dengan amicon® ultra-15 centrifugal filter devices,  kromatografi filtrasi gel dan kromatografi penukar anion  mengalami peningkatan berturut-turut sebesar 15,1; 34,7 dan96,0 U/mg. Hasil karakterisasi menunjukkan aktivitas  tertinggi pada pH 7, suhu 60 °C dan stabil pada suhu 4 °C. Analisis SDS-PAGE dan zimogram menunjukkan berat molekul protein xilanase berkisar 25 kDa. Jenis gula reduksi yang  dihasilkan yaitu xiloheksosa, xilotriosa, dan xilobiosa.


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