Transformation of aliphatic and aromatic nitriles by a nitrilase from Pseudomonas sp.

1999 ◽  
Vol 45 (10) ◽  
pp. 811-815 ◽  
Author(s):  
Jasvinder Dhillon ◽  
Suneel Chhatre ◽  
Rishi Shanker ◽  
N Shivaraman
Keyword(s):  
Carboxylic Acids ◽  
Potassium Cyanide ◽  
Nitrogen Sources ◽  
Cell Extract ◽  
Garden Soil ◽  
Partial Purification ◽  
Pseudomonas Sp ◽  
Aromatic Nitriles ◽  
A Cell ◽  
Hydrolysis Of

A Pseudomonas sp. (S1) isolated from a garden soil possessed a unique nitrilase, which is capable of catalyzing the direct hydrolysis of both potassium and organic cyanides to their corresponding carboxylic acids and ammonia, without the formation of amide as an intermediate. The nitrilase was purified with 4.8% recovery in three steps from a cell extract of the strain. The relative mobility of the homogenous enzyme preparation in SDS and native polyacrylamide gels indicated molecular weight of 41 kDa, approximately. Pseudomonas sp. (S1) utilized all the nitriles as carbon and nitrogen sources. The enzyme was induced by both aliphatic and aromatic nitriles, while the aliphatic olefinic nitrile - acrylonitrile was the most suitable substrate. The nitrilase also catalyzed the hydrolysis of acetonitrile, adiponitrile, benzonitrile, butyronitrile, glutaronitrile, phenylacetonitrile, succinodinitrile, and potassium cyanide, with the formation of ammonia and the corresponding carboxylic acids. The Michaelis-Menten constant, Km, of the partially purified nitrilase for acetonitrile, acrylonitrile, adiponitrile, benzonitrile, and potassium cyanide presented values of 11.26, 5.88, 10.28, 12.27, and 0.75 mM, respectively.Key words: nitriles, enzyme kinetics, nitrilase, partial purification, Pseudomonas sp.

scholarly journals Ferric Hydrogensulfate As a Reusable Heterogeneous Catalyst for the Synthesis of 5-Substituted-1H-Tetrazoles and Amides

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Hossein Eshghi ◽  
Seyed Mohammad Seyedi ◽  
Elaheh Rahimi Zarei
Keyword(s):  
Heterogeneous Catalyst ◽  
Carboxylic Acids ◽  
Sodium Azide ◽  
Aromatic Nitriles ◽  
Simple Filtration ◽  
High Yields ◽  
Aqueous Conditions ◽  
Hydrolysis Of ◽  
Substituted 1

Ferric hydrogensulfate catalyzed the synthesis of 5-substituted 1H-tetrazoles via [2 + 3] cycloaddition of nitriles and sodium azide. This method has the advantages of high yields, simple methodology, and easy workup. The catalyst can be recovered by simple filtration and reused delivering good yields. Also, ferric hydrogensulfate catalyzed the hydrolysis of nitriles to primary amides under aqueous conditions. Various aliphatic and aromatic nitriles converted to the corresponding amides in good yields without any contamination with carboxylic acids.

scholarly journals Crystal structure of thermostable alkylsulfatase SdsAP from Pseudomonas sp. S9

2017 ◽  
Vol 37 (3) ◽  
Author(s):  
Lifang Sun ◽  
Pu Chen ◽  
Yintao Su ◽  
Zhixiong Cai ◽  
Lingwei Ruan ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Sodium Dodecyl ◽  
Titration Calorimetry ◽  
Pseudomonas Sp ◽  
Sterol Carrier Protein ◽  
Dimerization Domain ◽  
Alkyl Chains ◽  
Hydrolysis Of

A novel alkylsulfatase from bacterium Pseudomonas sp. S9 (SdsAP) was identified as a thermostable alkylsulfatases (type III), which could hydrolyze the primary alkyl sulfate such as sodium dodecyl sulfate (SDS). Thus, it has a potential application of SDS biodegradation. The crystal structure of SdsAP has been solved to a resolution of 1.76 Å and reveals that SdsAP contains the characteristic metallo-β-lactamase-like fold domain, dimerization domain, and C-terminal sterol carrier protein type 2 (SCP-2)-like fold domain. Kinetic characterization of SdsAP to SDS by isothermal titration calorimetry (ITC) and enzymatic activity assays of constructed mutants demonstrate that Y246 and G263 are important residues for its preference for the hydrolysis of ‘primary alkyl’ chains, confirming that SdsAP is a primary alkylsulfatase.

scholarly journals Recurrent blooms of Heterosigma akashiwo (Raphidophyceae) in the Piraquê Channel, Rodrigo de Freitas Lagoon, southeast Brazil

2014 ◽  
Vol 74 (3) ◽  
pp. 529-537 ◽  
Author(s):  
S Branco ◽  
M Menezes ◽  
C Alves-de-Souza ◽  
P Domingos ◽  
MA Schramm ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Cell Extract ◽  
Heterosigma Akashiwo ◽  
Subsurface Water ◽  
Fish Mortality ◽  
Middle Section ◽  
Channel Depth ◽  
Southeast Brazil ◽  
A Cell ◽  
Janeiro State

Six blooms of Heterosigma akashiwo(Raphidophyceae) were observed from March 2007 through March 2008 in the Rodrigo de Freitas Lagoon, a semi-confined eutrophic system located in Rio de Janeiro state, southeast Brazil. Vegetative cells of H. akashiwo analysed by optical and electron microscopy showed morphology as described in the literature. The blooms (2.8 × 104 to 4 × 108 cell.L–1) were restricted to the middle section of the Piraquê Channel, which is situated in the northeastern part of the lagoon and receives freshwater inflow. The salinity of subsurface water and the channel depth showed significant negative correlations with H. akashiwo abundances, and appeared to restrict the blooms to this compartment of the lagoon. No fish mortality was associated with the H. akashiwo blooms, nor were brevetoxins detected in a cell extract obtained from the bloom observed on 19 March 2007.

Reaction Kinetics for the Hydrolysis of Titanium Isopropoxide Carboxylate Complexes

1992 ◽  
Vol 271 ◽  
Author(s):  
Charles D. Gagliardi ◽  
Dilum Dunuwila ◽  
Beatrice A. Van Vlierberge-Torgerson ◽  
Kris A. Berglund
Keyword(s):  
Carboxylic Acids ◽  
Ceramic Materials ◽  
Titanium Isopropoxide ◽  
General Interest ◽  
Chemical Transformations ◽  
Molecular Precursors ◽  
Novel Applications ◽  
Kinetics Of ◽  
Hydrolysis Of

ABSTRACTTitanium alkoxides modified by carboxylic acids have been widely studied as the molecular precursors to ceramic materials. These alkoxide complexes have also been very useful in the formation of stable, porous, optically clear films having many novel applications such as chemical sensors, catalytic supports, and ion-exchange media. To improve the processing of these materials, it is essential to better understand the kinetics of the chemical transformations which occur.The kinetics of the hydrolysis reaction are studied for selected carboxylic acids using Raman spectroscopy to probe the chemistry of the process. The study has a special emphasis on the titanium isopropoxide-valeric acid system due to the superior quality of these films over other carboxylates. Greater knowledge of the hydrolysis kinetics allows increased control over the quality of the film materials and should be of general interest to those working with modified metal alkoxides.

A Dictyostelium mutant with severe defects in alpha-actinin: its characterization using cDNA probes and monoclonal antibodies

1988 ◽  
Vol 90 (1) ◽  
pp. 59-71
Author(s):  
M. Schleicher ◽  
A. Noegel ◽  
T. Schwarz ◽  
E. Wallraff ◽  
M. Brink ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Polypeptide Chain ◽  
Mutant Cell ◽  
Polyacrylamide Gel Electrophoresis ◽  
Cell Extract ◽  
Binding Activity ◽  
Partial Purification ◽  
Wild Type ◽  
Coding Region ◽  
In The Wild

Cells of a Dictyostelium discoideum mutant deficient in binding a monoclonal antibody to alpha-actinin have previously been shown to grow and develop similarly to the wild type and to exert unimpaired chemotaxis as well as patching and capping of membrane proteins. Here we show that the normal 3.0 kb message for alpha-actinin is replaced in the mutant by two RNA species of approximately 3.1 and 2.8 kb. The 3.1 kb RNA was recognized by DNA fragments from all parts of the coding region, while the 2.8 kb RNA hybridized to all but a 3′-terminal fragment. Proteins synthesized in the mutant were analysed using four monoclonal antibodies that in the wild type specifically recognize the 95 × 10(3) Mr polypeptide of alpha-actinin. Cleavage mapping indicated that the binding sites of these antibodies are distributed over a region comprising more than half of the alpha-actinin polypeptide chain. In the mutant, three of the antibodies faintly labelled two polypeptides of 95 × 10(3) Mr and 88 × 10(3) Mr; the fourth antibody, which binds closest to one end of the polypeptide chain, faintly labelled the 95 × 10(3) Mr polypeptide only. The 88 × 10(3) Mr polypeptide most probably lacks the C-terminal portion of alpha-actinin. The binding of an antibody that recognized both polypeptides was quantified by a radio-immuno competition assay using wild-type alpha-actinin as a reference. In a mutant cell extract containing total soluble proteins the antibody binding activity was decreased to 1.1% when compared with wild-type extract. After their partial purification and SDS-polyacrylamide gel electrophoresis the mutant 95 × 10(3) Mr and 88 × 10(3) Mr polypeptides were barely detectable as Coomassie Blue-stained bands, indicating that in the mutant not only certain epitopes of alpha-actinin were altered but the entire molecule is almost completely lacking. When the fitness of mutant cells relative to wild type was determined during growth in nutrient medium, a slight disadvantage for the mutant was indicated, by finding selection coefficients between 0.03 and 0.05.

Isocarbostyrils. II. The Conversion of 2-Methyl-4-acyl-5-nitroisocarbostyrils to 2-Substituted Indole-4-carboxylic Acids

1971 ◽  
Vol 49 (17) ◽  
pp. 2797-2802 ◽  
Author(s):  
D. E. Horning ◽  
G. Lacasse ◽  
J. M. Muchowski
Keyword(s):  
Sulfuric Acid ◽  
Carboxylic Acid ◽  
Carboxylic Acids ◽  
Alkaline Hydrolysis ◽  
Mannich Reaction ◽  
Reductive Cyclization ◽  
Acid Catalyzed ◽  
Acid Anhydrides ◽  
Hydrolysis Of ◽  
Derivatives Of

The sulfuric acid catalyzed acylation of 2-methyl-5-nitroisocarbostyril with carboxylic acid anhydrides gave the corresponding 4-acylated derivatives 3, which underwent reductive cyclization to 2-substituted derivatives of 4-methyl-1,3,4,5-tetrahydropyrrolo[4.3.2.de]isoquinolin-5-one (4). Alkaline hydrolysis of the six-membered lactam in 4 was accompanied by a retro-Mannich reaction to produce 2-substituted indole-4-carboxylic acids in about 40 % overall yield from 3.

Syntheses of methyl glycosides of 6-deoxyheptoses

1994 ◽  
Vol 72 (1) ◽  
pp. 247-251 ◽  
Author(s):  
Gerald O. Aspinall ◽  
Armando G. McDonald ◽  
Ramesh K. Sood
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Gas Chromatography ◽  
Magnetic Resonance ◽  
Potassium Cyanide ◽  
Diisobutylaluminum Hydride ◽  
Carbohydrate Polymers ◽  
Magnetic Resonance Data ◽  
Resonance Data ◽  
Campylobacter Species ◽  
Hydrolysis Of

Methyl α-D-glycopyranosides of 6-deoxy-D-altro-heptose, 6-deoxy-D-manno-heptose, and 6-deoxy-D-talo-heptose have been prepared. Displacements of methyl 2,3,4-tri-O-benzylhexopyranoside 6-trifluoromethanesulfonates with potassium cyanide, followed by reduction of the resulting heptopyranosidurononitriles with diisobutylaluminum hydride, hydrolysis of the imine, further reduction with sodium borohydride, and catalytic O-debenzylation, give the corresponding methyl 6-deoxyheptopyranosides. Configurational change at C-4 of methyl 6-deoxy-7-O-tert-butyldiphenylsilyl-α-D-manno-heptopyranoside to give the talo isomer was effected by oxidation followed by stereoselective reduction. 1H nuclear magnetic resonance data of the glycosides, and gas chromatography of acetylated glycosides of (R)- and (S)-2-butanol serve to establish ring and enantiomeric configurations of the parent sugars when these are encountered as constituents of lipopolysaccharides or extracellular carbohydrate polymers, as in Campylobacter species.

scholarly journals Molecular Identification of Family 38 α-Mannosidase of Bacillus sp. Strain GL1, Responsible for Complete Depolymerization of Xanthan

2002 ◽  
Vol 68 (6) ◽  
pp. 2731-2736 ◽  
Author(s):  
Hirokazu Nankai ◽  
Wataru Hashimoto ◽  
Kousaku Murata
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Cell Extract ◽  
Amino Acid Sequences ◽  
Glycoside Hydrolase Family ◽  
Sequence Information ◽  
Reading Frame ◽  
A Cell ◽  
Terminal Amino ◽  
Amino Acid Sequence Information

ABSTRACT When cells of Bacillus sp. strain GL1 were grown in a medium containing xanthan as a carbon source, α-mannosidase exhibiting activity toward p-nitrophenyl-α-d-mannopyranoside (pNP-α-d-Man) was produced intracellularly. The 350-kDa α-mannosidase purified from a cell extract of the bacterium was a trimer comprising three identical subunits, each with a molecular mass of 110 kDa. The enzyme hydrolyzed pNP-α-d-Man (Km = 0.49 mM) and d-mannosyl-(α-1,3)-d-glucose most efficiently at pH 7.5 to 9.0, indicating that the enzyme catalyzes the last step of the xanthan depolymerization pathway of Bacillus sp. strain GL1. The gene for α-mannosidase cloned most by using N-terminal amino acid sequence information contained an open reading frame (3,144 bp) capable of coding for a polypeptide with a molecular weight of 119,239. The deduced amino acid sequence showed homology with the amino acid sequences of α-mannosidases belonging to glycoside hydrolase family 38.

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