scholarly journals Substrate Specificity of Atrazine Chlorohydrolase and Atrazine-Catabolizing Bacteria

2000 ◽  
Vol 66 (10) ◽  
pp. 4247-4252 ◽  
Author(s):  
Jennifer L. Seffernick ◽  
Gilbert Johnson ◽  
Michael J. Sadowsky ◽  
Lawrence P. Wackett
Keyword(s):  
Substrate Specificity ◽  
Homologous Gene ◽  
Clavibacter Michiganensis ◽  
Amino Groups ◽  
Substrate Analogs ◽  
Cell Extracts ◽  
Alkyl Groups ◽  
Chlorine Substituent ◽  
Cyano Groups ◽  
Hydrolysis Of

ABSTRACT Bacterial atrazine catabolism is initiated by the enzyme atrazine chlorohydrolase (AtzA) in Pseudomonas sp. strain ADP. Other triazine herbicides are metabolized by bacteria, but the enzymological basis of this is unclear. Here we begin to address this by investigating the catalytic activity of AtzA by using substrate analogs. Purified AtzA from Pseudomonas sp. strain ADP catalyzed the hydrolysis of an atrazine analog that was substituted at the chlorine substituent by fluorine. AtzA did not catalyze the hydrolysis of atrazine analogs containing the pseudohalide azido, methoxy, and cyano groups or thiomethyl and amino groups. Atrazine analogs with a chlorine substituent at carbon 2 and N-alkyl groups, ranging in size from methyl to t-butyl, all underwent dechlorination by AtzA. AtzA catalyzed hydrolytic dechlorination when one nitrogen substituent was alkylated and the other was a free amino group. However, when both amino groups were unalkylated, no reaction occurred. Cell extracts were prepared from five strains capable of atrazine dechlorination and known to containatzA or closely homologous gene sequences:Pseudomonas sp. strain ADP, Rhizobium strain PATR, Alcaligenes strain SG1, Agrobacterium radiobacter J14a, and Ralstonia picketti D. All showed identical substrate specificity to purified AtzA fromPseudomonas sp. strain ADP. Cell extracts fromClavibacter michiganensis ATZ1, which also contains a gene homologous to atzA, were able to transform atrazine analogs containing pseudohalide and thiomethyl groups, in addition to the substrates used by AtzA from Pseudomonas sp. strain ADP. This suggests that either (i) another enzyme(s) is present which confers the broader substrate range or (ii) the AtzA itself has a broader substrate range.

scholarly journals CDP-2,3-Di-O-Geranylgeranyl-sn-Glycerol:l-Serine O-Archaetidyltransferase (Archaetidylserine Synthase) in the Methanogenic Archaeon Methanothermobacter thermautotrophicus

2003 ◽  
Vol 185 (4) ◽  
pp. 1181-1189 ◽  
Author(s):  
Hiroyuki Morii ◽  
Yosuke Koga
Keyword(s):  
Substrate Specificity ◽  
Maximal Activity ◽  
Chemical Degradation ◽  
Reaction Products ◽  
Gene Encoding ◽  
Substrate Analogs ◽  
Cell Extracts ◽  
Phosphatidylserine Synthase ◽  
Methanothermobacter Thermautotrophicus ◽  
Triton X

ABSTRACT CDP-2,3-di-O-geranylgeranyl-sn-glycerol:l-serine O-archaetidyltransferase (archaetidylserine synthase) activity in cell extracts of Methanothermobacter thermautotrophicus cells was characterized. The enzyme catalyzed the formation of unsaturated archaetidylserine from CDP-unsaturated archaeol and l-serine. The identity of the reaction products was confirmed by thin-layer chromatography, fast atom bombardment-mass spectrum analysis, and chemical degradation. The enzyme showed maximal activity in the presence of 10 mM Mn2+ and 1% Triton X-100. Among various synthetic substrate analogs, both enantiomers of CDP-unsaturated archaeols with ether-linked geranylgeranyl chains and CDP-saturated archaeol with ether-linked phytanyl chains were similarly active toward the archaetidylserine synthase. The activity on the ester analog of the substrate was two to three times higher than that on the corresponding ether-type substrate. The activity of d-serine with the enzyme was 30% of that observed for l-serine. A trace amount of an acid-labile, unsaturated archaetidylserine intermediate was detected in the cells by a pulse-labeling experiment. A gene (MT1027) in M. thermautotrophicus genome annotated as the gene encoding phosphatidylserine synthase was found to be homologous to Bacillus subtilis pssA but not to Escherichia coli pssA. The substrate specificity of phosphatidylserine synthase from B. subtilis was quite similar to that observed for the M. thermautotrophicus archaetidylserine synthase, while the E. coli enzyme had a strong preference for CDP-1,2-diacyl-sn-glycerol. It was concluded that M. thermautotrophicus archaetidylserine synthase belongs to subclass II phosphatidylserine synthase (B. subtilis type) on the basis of not only homology but also substrate specificity and some enzymatic properties. The possibility that a gene encoding the subclass II phosphatidylserine synthase might be transferred from a bacterium to an ancestor of methanogens is discussed.

Potential Inhibitors of Phosphoenolpyruvate (PEP) Carboxylase: Phosphonic Acid Substrate-Analogs Derived From Stobbe-Type Condensations of Ethyl 3-(Diethoxyphosphinoyl)propanoate

1987 ◽  
Vol 40 (10) ◽  
pp. 1619 ◽  
Author(s):  
HG Mcfadden ◽  
RLN Harris ◽  
CLD Jenkins
Keyword(s):  
Phosphonic Acid ◽  
Acid Group ◽  
Pep Carboxylase ◽  
Substrate Analogs ◽  
Alkyl Groups ◽  
Potential Inhibitors ◽  
Mild Hydrolysis ◽  
Hydrolysis Of ◽  
Acid Substrate ◽  
Partial Esters

Phosphonic acid analogues of 2-(dihydroxyphosphinoy1oxy)propenoic acid (PEP), the substrate of PEP carboxylase, were prepared and tested as inhibitors of the enzyme. The required triacids were obtained by mild hydrolysis of the partial esters prepared by Stobbe-like condensation of aryl and alkyl carbonyl compounds with ethyl 3-(diethoxyphosphinoyl)propanoate. Condensations with aldehydes gave predominantly (9-propenoates while reactions with ketones gave mixtures of (E)- and (Z)-isomers and also, in some cases, products with the double bond rearranged to the &position. Although compounds tested were inhibitory, none was as effective as previously reported phosphate PEP analogues. Results indicate that the presence of a methyl group cis to the carboxylic acid group enhances inhibitory activity but that trans alkyl groups decrease inhibitor effectiveness.

Kinetics of the Imidazolium Ring-Opening of mRNA 5'-cap Analogs in Aqueous Alkali

2006 ◽  
Vol 71 (4) ◽  
pp. 567-578 ◽  
Author(s):  
Alicja Stachelska ◽  
Zbigniew J. Wieczorek ◽  
Janusz Stępiński ◽  
Marzena Jankowska-Anyszka ◽  
Harri Lönnberg ◽  
...  
Keyword(s):  
Electrostatic Interaction ◽  
Ring Opening ◽  
Nucleophilic Attack ◽  
Amino Groups ◽  
Hydroxide Ion ◽  
Methyl Group ◽  
Structural Modifications ◽  
Alkyl Groups ◽  
Imidazolium Ring ◽  
Kinetics Of

Second-order rate constants for the hydroxide-ion-catalyzed imidazolium ring-opening of several mono- and dinucleosidic analogs of mRNA 5'-cap have been determined. Intramolecular stacking of the two nucleobases in the dinucleosidic analogs, m7GpppN (m7G = 7-methylguanosine, N = 5'-linked nucleoside), and electrostatic interaction between the N-alkylated imidazolium ring and phosphate moiety have been shown to shield the m7G moiety against the nucleophilic attack of hydroxide ion. In addition, the effect of methylation of the nucleobase amino groups and replacement of the 7-methyl group with other alkyl groups have been studied. The influence of all the structural modifications studied turned out to be modest, the cleavage rates of the most and least reactive analogs (with the exception of non-phosphorylated nucleosides) differing only by a factor of 5.

Synthesis and Tautomerism of Curcumin Derivatives and Related Compounds

2015 ◽  
Vol 68 (2) ◽  
pp. 224 ◽  
Author(s):  
Hiroyasu Taguchi ◽  
Daijiro Yanagisawa ◽  
Shigehiro Morikawa ◽  
Koichi Hirao ◽  
Nobuaki Shirai ◽  
...  
Keyword(s):  
Parent Compound ◽  
Amyloid Plaques ◽  
Enol Form ◽  
19F Nmr ◽  
Enolic Form ◽  
Curcumin Derivatives ◽  
Alkyl Groups ◽  
Alzheimer Brain ◽  
Hydrolysis Of ◽  
Related Compounds

1,7-Bis(4′-hydroxy-3′-trifluoromethoxyphenyl)-1,6-heptadiene-3,5-dione (2a), related to curcumin, and thirteen 4-substituted derivatives were prepared and their keto/enol ratio in DMSO[D6] was determined by 19F NMR because the enolic form of these related curcumins had been shown to bind to amyloid plaques in the Alzheimer brain. The parent compound and the 4-ethoxycarbonyl derivative were almost 100 % in the enolic form that contains a conjugated hepta-1,4,6-trien-3-on-5-ol backbone. Enolisation decreased to varying amounts in the derivatives that had 4-substituted alkyl groups. Attempts to prepare the 4-hydroxypropyl derivative by hydrolysis of O-methoxymethyl 2m or O-tetrahydropyranyloxy 2n protected derivatives led to cyclised products. A related pyrimidine compound 6b that mimicked a fixed enol form was also prepared.

scholarly journals Erratum to: “Self-assembling catalytic systems based on new amphiphile containing purine fragment, exhibiting substrate specificity in hydrolysis of phosphorus acids esters”

2017 ◽  
Vol 87 (7) ◽  
pp. 1649-1649
Author(s):  
D. A. Samarkina ◽  
D. R. Gabdrakhmanov ◽  
V. E. Semenov ◽  
F. G. Valeeva ◽  
L. M. Gubaidullina ◽  
...  
Keyword(s):  
Substrate Specificity ◽  
Catalytic Systems ◽  
Self Assembling ◽  
Hydrolysis Of

Characterization of a factor that stimulates hydrolysis of GTP bound to ras gene product p21 (GTPase-activating protein) and correlation of its activity to cell density

1988 ◽  
Vol 8 (10) ◽  
pp. 4169-4173
Author(s):  
M Hoshino ◽  
M Kawakita ◽  
S Hattori
Keyword(s):  
Gene Product ◽  
Cell Density ◽  
Cultured Cells ◽  
Specific Activity ◽  
Gtpase Activating Protein ◽  
Ras Gene ◽  
Cell Extracts ◽  
Mouse Tissues ◽  
Almost All ◽  
Hydrolysis Of

The postmicrosomal fraction of the extract from NIH 3T3 and BALB/c 3T3 cells stimulated the hydrolysis of GTP bound to H-ras gene product p21 by severalfold. The stimulation was observed with normal p21 but not with p21 with valine as the 12th residue. This specificity is similar to that of GTPase-activating protein (GAP) for N-ras p21 described by M. Trahey and F. McCormick (Science 238:542-545, 1987). Consistent with this specificity, analysis of p21-bound nucleotides in living cells revealed that almost all normal p21 bound GDP, whereas oncogenic mutant p21s bound both GTP and GDP. Similar activity was also found in various mouse tissues, with brain tissue showing the highest specific activity. When cell extracts were prepared from cultured cells, there was a linear relationship between GAP activity and cell density. These results suggest the factor is involved in the regulation of cell proliferation.

A simple procedure using trinitrobenzenesulphonic acid for monitoring proteolysis in cheese

1988 ◽  
Vol 55 (4) ◽  
pp. 585-596 ◽  
Author(s):  
Anna Polychroniadou
Keyword(s):  
Simple Procedure ◽  
Water Soluble ◽  
Acid Solutions ◽  
Amino Groups ◽  
Total N ◽  
Cheese Ripening ◽  
Amino Acid Solutions ◽  
Hydrolysis Of ◽  
Good Agreement

SummaryA simple, rapid and sensitive spectrophotometric assay was developed and evaluated for monitoring proteolysis during cheese ripening, based on the fact that α-amino groups released by hydrolysis of cheese proteins react with trinitrobenzenesulphonic acid to form products that absorb strongly at 420 nm. A linear relationship was shown to exist between A420 and concentration of free α amino groups up to 0·5 HIM (r = 0·999, 38 df, P < 0·001). Repeatability of the method was satisfactory. The coefficient of variance was 0·53% for amino acid solutions and 1·19% for cheese extracts. Average recovery of glycine added to the cheese was 104 ± 2·9%. A comparison of the above method with that of determination of water-soluble N to total N ratio showed that there was good agreement between these two methods of assessment of proteolysis in cheese (r = 0·857, 32 df, P < 0·001). Mainly Feta and Teleme cheese were examined, but a similar correlation was obtained with hard Greek cheeses. Analytical conditions of the procedure are discussed.

Dinuclear Zinc(II) Complexes of Linear and Cyclic Peptides Containing Two Bis(2-pyridylmethyl)amino Groups as Catalysts for Hydrolysis of RNA Model Substrate

2001 ◽  
pp. 516-517
Author(s):  
Masao Kawai ◽  
Hatsuo Yamamura ◽  
Nobuko Izuhara ◽  
Tomotsugu Kawaguchi ◽  
Ryoji Tanaka ◽  
...  
Keyword(s):  
Cyclic Peptides ◽  
Amino Groups ◽  
Hydrolysis Of

scholarly journals Biodegradation of low molecular weight polyacrylamide under aerobic and anaerobic conditions: effect of the molecular weight

2020 ◽  
Vol 81 (2) ◽  
pp. 301-308 ◽  
Author(s):  
Wenzhe Song ◽  
Yu Zhang ◽  
Amir Hossein Hamidian ◽  
Min Yang
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Carbon Chain ◽  
Anaerobic Treatment ◽  
Low Molecular Weight ◽  
Amino Groups ◽  
Molecular Weights ◽  
Weight One ◽  
Hydrolysis Of ◽  
Aerobic And Anaerobic

Abstract The biodegradation of polyacrylamide (PAM) includes the hydrolysis of amino groups and cleavage of the carbon chain; however, the effect of molecular weight on the biodegradation needs further investigations. In this study, biodegradation of low molecular weight PAM (1.6 × 106 Da) was evaluated in two aerobic (25 °C and 40 °C) and two anaerobic (35 °C and 55 °C) reactors over 100 days. The removal of the low molecular weight PAM (52.0–52.6%) through the hydrolysis of amino groups by anaerobic treatment (35 °C and 55 °C) was much higher than that of the high molecular weight (2.2 × 107 Da, 11.2–17.0%) observed under the same conditions. The molecular weight was reduced from 1.6 × 106 to 6.45–7.42 × 105 Da for the low molecular weight PAM, while the high molecular weight PAM declined from 2.2 × 107 to 3.76–5.87 × 106 Da. The results showed that the amino hydrolysis of low molecular weight PAM is easier than that of the high molecular weight one, while the cleavage of its carbon chain is still difficult. The molecular weights of PAM in the effluents from the two aerobic reactors (25 °C and 40 °C) were further reduced to 4.31 × 105 and 5.68 × 105 Da by the biofilm treatment, respectively. The results would be useful for the management of wastewater containing PAM.

THE ACETYLATION OF THROMBIN

1959 ◽  
Vol 37 (1) ◽  
pp. 1361-1366 ◽  
Author(s):  
Ricardo H. Landaburu ◽  
Walter H. Seegers
Keyword(s):  
Methyl Ester ◽  
Proteolytic Activity ◽  
Basic Structure ◽  
Amino Groups ◽  
Spontaneous Hydrolysis ◽  
Optimum Ph ◽  
Hydrolysis Of

Purified thrombin-C loses its clotting power upon acetylation. The thrombin-E which is produced during the acetylation has approximately twice the proteolytic activity as the original thrombin-C. Evidently amino groups are not necessary to have thrombin-E activity, but if o-acyl groups are also produced the enzyme does not hydrolyze p-toluenesulphonylarginine methyl ester (TAMe). The activity can be recovered by spontaneous hydrolysis of the o-acyl groups at pH 8.5. Thrombin-E does not activate fibrinogen, but does lyse fibrin. The optimum pH with TAMe as substrate is 8.8. It may be that thrombin-C is a dimer of the basic structure in thrombin-E.

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