scholarly journals Purification and Characterization of Thermostable Endo-1,5-α-l-Arabinase from a Strain of Bacillus thermodenitrificans

2002 ◽  
Vol 68 (4) ◽  
pp. 1639-1646 ◽  
Author(s):  
Makoto Takao ◽  
Kana Akiyama ◽  
Takuo Sakai

ABSTRACT A strain of a thermophilic bacterium, tentatively designated Bacillus thermodenitrificans TS-3, with arabinan-degrading activity was isolated. It produced an endo-arabinase (ABN) (EC 3.2.1.99) and two arabinofuranosidases (EC 3.2.1.55) extracellularly when grown at 60°C on a medium containing sugar beet arabinan. The ABN (tentatively called an ABN-TS) was purified 7,417-fold by anion-exchange, hydrophobic, size exclusion, and hydroxyapatite chromatographies. The molecular mass of ABN-TS was 35 kDa as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and the isoelectric point was pH 4.5. The enzyme was observed to be more thermostable than known ABNs; it had a half-life of 4 h at 75°C. The enzyme had optimal activity at 70°C and pH 6.0. The enzyme had apparent Km values of 8.5 and 45 mg/ml and apparent V max values of 1.6 and 1.1 mmol/min/mg of protein against debranched arabinan (α-1,5-arabinan) and arabinan, respectively. The enzyme had no pectin-releasing activity (protopectinase activity) from sugar beet protopectin, differing from an ABN (protopectinase-C) from mesophilic Bacillus subtilis IFO 3134. The pattern of degradation of debranched arabinan by ABN-TS indicated that the enzyme was an endo-acting enzyme and the main end products were arabinobiose and arabinose. The results of preliminary experiments indicated that the culture filtrate of strain TS-3 is suitable for l-arabinose production from sugar beet pulp at high temperature.

2010 ◽  
Vol 192 (9) ◽  
pp. 2407-2413 ◽  
Author(s):  
Jacalyn M. Green ◽  
Ryan Hollandsworth ◽  
Lenore Pitstick ◽  
Eric L. Carter

ABSTRACT The abg locus of the Escherichia coli chromosome includes three genes encoding proteins (AbgA, AbgB, and AbgT) that enable uptake and utilization of the folate breakdown product, p-aminobenzoyl-glutamate (PABA-GLU). We report on the purification and characterization of the p-aminobenzoyl-glutamate hydrolase (PGH) holoenzyme encoded by abgA and abgB. One-step purification was accomplished using a plasmid carrying abgAB with a hexahistidine tag on the carboxyl terminus of AbgB and subsequent metal affinity chromatography (MAC). Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed two subunits (∼53-kDa and ∼47-kDa proteins) of the expected masses of AbgB and AbgA; N-terminal sequencing confirmed the subunit identification, and amino acid analysis yielded a 1:1 ratio of the subunits. Size exclusion chromatography coupled with light-scattering analysis of purified PGH revealed a predominant molecular mass of 206 kDa and a minor component of 400 to 500 kDa. Both peaks contained PGH activity, and SDS-PAGE revealed that fractions containing activity were composed of both AbgA and AbgB. MAC-purified PGH was highly stimulated by manganese chloride. Kinetic analysis of MAC-purified PGH revealed a Km value for PABA-GLU of 60 ± 0.08 μM and a specific activity of 63,300 ± 600 nmol min−1 mg−1. Folic acid and a variety of dipeptides served as poor substrates of PGH. This locus of the E. coli chromosome may encode a portion of a folate catabolism pathway.


1988 ◽  
Vol 66 (1) ◽  
pp. 32-39 ◽  
Author(s):  
Eduardo T. Cánepa ◽  
Elena B.C. Llambías

Pig liver ferrochelatase was purified 465-fold with about 30% yield, to apparent homogeneity, by a procedure involving solubilization from mitochondria, ammonium sulfate fractionation, and Sephacryl S-300 chromatography. The fraction of each purification step had cobaltochelatase as well as ferrochelatase activity. A purified protein of molecular weight 40 000 was found by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. A molecular weight of approximately 240 000 was obtained by Sephacryl S-300 chromatography. Both activities of the purified fraction increased linearly with time until 2 h. but nonlinear plots were obtained with increasing concentrations of protein. Their optimum pH values were similar. Km values were, for ferrochelatase activity, 23.3 μM for the metal and 30.3 μM for mesoporphyrin. and for cobaltochelatase activity. 27 and 45.5 μM, respectively. Fe2+ and Co2+ each protected against inactivation by heat. Pb2+, Zn2+, Cu2+, or Hg2+ inhibited both activities, while Mn2+ slightly activated; Mg2+ had no effect, at the concentrations tested. There appeared to be an involvement of sulfhydryl groups in metal insertion. Lipids, in correlation with their degree of unsaturation, activated both purified activities; phospholipids also had activation effects. We conclude that a single protein catalyzes the insertion of Fe2+ or Co2+ into mesoporphyrin.


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.


1986 ◽  
Vol 239 (3) ◽  
pp. 699-704 ◽  
Author(s):  
S Chaudhuri ◽  
J M Lambert ◽  
L A McColl ◽  
J R Coggins

A procedure has been developed for the purification of 3-dehydroquinase from Escherichia coli. Homogeneous enzyme with specific activity 163 units/mg of protein was obtained in 19% overall yield. The subunit Mr estimated from polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate was 29,000. The native Mr, estimated by gel permeation chromatography on Sephacryl S-200 (superfine) and on TSK G3000SW, was in the range 52,000-58,000, indicating that the enzyme is dimeric. The catalytic properties of the enzyme have been determined and shown to be very similar to those of the biosynthetic 3-dehydroquinase component of the arom multifunctional enzyme of Neurospora crassa.


1981 ◽  
Vol 60 (2) ◽  
pp. 199-205 ◽  
Author(s):  
Naotika Toki ◽  
Hiroyuki Sumi ◽  
Sumiyoshi Takasugi

1. A kallikrein-like enzyme in plasma of patients with acute pancreatitis was further purified by successive hydroxyapatite/cellulose and Sepharose-4B column chromatography. 2. By these procedures 0.26 mg of purified enzyme with a specific activity of 215 S-2266 chromozyme units/mg of protein was obtained from 10 ml of original plasma. 3. The purified material was homogeneous as ascertained by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and had an apparent molecular weight of 31 000 as measured by gel filtration on Sephadex G-200. 4. It was confirmed immunologically that this enzyme was pancreatic kallikrein, which is distinct from plasma kallikrein, and that it could combine with α2-macroglobulin only in the presence of trypsin.


1983 ◽  
Vol 29 (10) ◽  
pp. 1361-1368 ◽  
Author(s):  
Thomas P. Poirier ◽  
Stanley C. Holt

Capnocytophaga ochracea acid (AcP; EC 3.1.3.2) and alkaline (AlP; EC 3.1.3.1) phosphatase was isolated by Ribi cell disruption and purified by sodium dodecyl sulphate – polyacrylamide gel electrophoresis (SDS–PAGE.) Both phosphatases eluted from Sephadex G-150 consistent with molecular weights (migration) of 140 000 and 110 000. SDS–PAGE demonstrated a 72 000 and 55 000 subunit molecular migration for AcP and AlP, respectively. The kinetics of activity of purified AcP and AIP on p-nitrophenol phosphate and phosphoseryl residues of the phosphoproteins are presented.


1984 ◽  
Vol 160 (3) ◽  
pp. 772-787 ◽  
Author(s):  
J A Schmidt

A protocol for the rapid, efficient purification of the major charged species of human interleukin 1 (IL-1) has been developed using high performance anion exchange and size exclusion chromatography. The isolated material is pure as determined by sodium dodecyl sulfate (SDS) gradient polyacrylamide gel electrophoresis (PAGE) and analytical isoelectric focusing (IEF). The molecular weight of the purified material is 15,000 and the isoelectric point (pI) is 6.8, values that are in good agreement with those previously reported for human IL-1. 10(-10) M concentrations of the purified material give half-maximal stimulation in the thymocyte proliferation assay. Amounts of IL-1 sufficient for receptor studies and detailed biochemical analysis can now be produced on a regular basis.


2018 ◽  
Vol 10 (1) ◽  
pp. 33-45
Author(s):  
Syed Abid Ali ◽  
Fozia Humayun ◽  
Iqra Munir ◽  
Shakil Ahmad ◽  
Zarrien Ayub ◽  
...  

Objective: The present study was conducted to investigate the biomass assessment, morphological and molecular identification, nutritive status and biochemical characterization of three major Thais species (T. bufo, T. hippocastanum and T. rudolphi) from the Sindh Coast, Pakistan. Methods: Samples were collected from Buleji and Paradise Point at the Sindh Coast. Species were identified morphologically as well as genetically by amplifying two mitochondrial 16S rDNA & Cytochrome Oxidase I (COI) and one nuclear (Histone H3) genes. Shell microstructure and chemistry were also studied by scanning electron microscopy and Energy Dispersive X-ray spectrometry (EDX). The body muscle was dissected and used for nutritional composition determination such as estimation of total protein, carbohydrates, lipids, protein fingerprinting by Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis (SDS-PAGE) and Size-Exclusion - Fast Protein Liquid Chromatography (SEC-FPLC), amino acid and fatty acid analysis. Results: Nutritionally, the total protein was found to be the major content followed by carbohydrate and lipid in the three Thais sp. The presence of medicinally important hemocyanin as abundant hemolymph protein was confirmed via SDS-PAGE and SEC FPLC. Nine different types of fatty acids and a high concentration of essential amino acids were also determined. Conclusion: Our findings suggest that Thais sp. are nutritionally rich and can be consumed as a valuable marine resource to overcome the malnutrition problem in developing countries.


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