Localization and characterization of two structurally different forms of acetyl-CoA carboxylase in young pea leaves, of which one is sensitive to aryloxyphenoxypropionate herbicides

Young pea leaves contain two structurally different forms of acetyl-CoA carboxylase (EC 6.4.1.2; ACCase). A minor form, which accounted for about 20% of the total ACCase activity in the whole leaf, was detected in the epidermal tissue. This enzyme was soluble and was purified to homogeneity from young pea leaf extracts. It consisted of a dimer of two identical biotinyl subunits of molecular mass 220 kDa. In this respect, this multifunctional enzyme was comparable with that described in other plants and in other eukaryotes. A predominant form was present in both the epidermal and mesophyll tissues. In mesophyll protoplasts, ACCase was detected exclusively in the soluble phase of chloroplasts. This enzyme was partially purified from pea chloroplasts and consisted of a freely dissociating complex, the activity of which may be restored by combination of its separated constituents. The partially purified enzyme was composed of several subunits of molecular masses ranging from 32 to 79 kDa, for a native molecular mass > 600 kDa. One of these subunits, of molecular mass 38 kDa, was biotinylated. This complex subunit structure was comparable with that of microorganisms and was referred to as a ‘prokaryotic’ form of ACCase. Biochemical parameters were determined for both ACCase forms. Finally, both pea leaf ACCases exhibited different sensitivities towards the grass ACCase herbicide, diclofop. This compound had no effect on the ‘prokaryotic’ form of ACCase, while the ‘eukaryotic’ form was strongly inhibited.

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Characterization of dissolved material during the initial phase of softwood kraft pulping

TAPPI Journal ◽

10.32964/tj12.1.37 ◽

2013 ◽

Vol 12 (1) ◽

pp. 37-43 ◽

Cited By ~ 1

Author(s):

HANNU PAKKANEN ◽

TEEMU PALOHEIMO ◽

RAIMO ALÉN

Keyword(s):

Mass Transfer ◽

Molecular Mass ◽

Initial Phase ◽

Degradation Products ◽

Kraft Pulping ◽

Reaction Products ◽

Cooking Temperature ◽

Molecular Masses ◽

Aliphatic Carboxylic Acids

The influence of various cooking parameters, such as effective alkali, cooking temperature, and cooking time on the formation of high molecular mass lignin-derived and low molecular mass carbohydrates-derived (aliphatic carboxylic acids) degradation products, mainly during the initial phase of softwood kraft pulping was studied. In addition, the mass transfer of all of these degradation products was clarified based on their concentrations in the cooking liquor inside and outside of the chips. The results indicated that the degradation of the major hemicellulose component, galactoglucomannan, typically was dependent on temperature, and the maximum degradation amount was about 60%. In addition, about 60 min at 284°F (140°C) was needed for leveling off the concentrations of the characteristic reaction products (3,4-dideoxy-pentonic and glucoisosaccharinic acids) between these cooking liquors. Compared with low molecular mass aliphatic acids, the mass transfer of soluble lignin fragments with much higher molecular masses was clearly slower.

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Kinetic studies on two isoforms of acetyl-CoA carboxylase from maize leaves

Biochemical Journal ◽

10.1042/bj3180997 ◽

1996 ◽

Vol 318 (3) ◽

pp. 997-1006 ◽

Cited By ~ 36

Author(s):

Derek HERBERT ◽

Lindsey J PRICE ◽

Claude ALBAN ◽

Laure DEHAYE ◽

Dominique JOB ◽

...

Keyword(s):

Kinetic Studies ◽

Product Inhibition ◽

Hill Equation ◽

Acetyl Coa Carboxylase ◽

Acetyl Coa ◽

Maize Leaves ◽

Ic50 Values ◽

A Minor ◽

The Hill

The steady-state kinetics of two multifunctional isoforms of acetyl-CoA carboxylase (ACCase) from maize leaves (a major isoform, ACCase1 and a minor isoform, ACCase2) have been investigated with respect to reaction mechanism, inhibition by two graminicides of the aryloxyphenoxypropionate class (quizalofop and fluazifop) and some cellular metabolites. Substrate interaction and product inhibition patterns indicated that ADP and Pi products from the first partial reaction were not released before acetyl-CoA bound to the enzymes. Product inhibition patterns did not match exactly those predicted for an ordered Ter Ter or a random Ter Ter mechanism, but were close to those postulated for an ordered mechanism. ACCase2 was about 1/2000 as sensitive as ACCase1 to quizalofop but only about 1/150 as sensitive to fluazifop. Fitting inhibition data to the Hill equation indicated that binding of quizalofop or fluazifop to ACCase1 was non-cooperative, as shown by the Hill constant (napp) values of 0.86 and 1.16 for quizalofop and fluazifop respectively. Apparent inhibition constant values (K´ from the Hill equation) for ACCase1 were 0.054 µM for quizalofop and 21.8 µM for fluazifop. On the other hand, binding of quizalofop or fluazifop to ACCase2 exhibited positive co-operativity, as shown by the napp values of 1.85 and 1.59 for quizalofop and fluazifop respectively. K´ values for ACCase2 were 1.7 mM for quizalofop and 140 mM for fluazifop. Kinetic parameters for the co-operative binding of quizalofop to maize ACCase2 were close to those of another multifunctional ACCase of limited sensitivity to graminicide, ACC220 from pea. Inhibition of ACCase1 by quizalofop was mixed-type with respect to acetyl-CoA or ATP, but the concentration of acetyl-CoA had the greater effect on the level of inhibition. Neither ACCase1 nor ACCase2 was appreciably sensitive to CoA esters of palmitic acid (16:0) or oleic acid (18:1). Approximate IC50 values were 10 µM (ACCase2) and 50 µM (ACCase1) for both CoA esters. Citrate concentrations up to 1 mM had no effect on ACCase1 activity. Above this concentration, citrate was inhibitory. ACCase2 activity was slightly stimulated by citrate over a broad concentration range (0.25–10 mM). The significance of possible effects of acyl-CoAs or citrate in vivo is discussed.

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Structural Characterization of i-Motif Structure in the Human Acetyl-CoA Carboxylase 1 Gene Promoters and Their Role in the Regulation of Gene Expression

ChemBioChem ◽

10.1002/cbic.201800021 ◽

2018 ◽

Vol 19 (10) ◽

pp. 1078-1087 ◽

Cited By ~ 6

Author(s):

Mangesh H. Kaulage ◽

Santanu Bhattacharya ◽

K. Muniyappa

Keyword(s):

Gene Expression ◽

Structural Characterization ◽

Regulation Of Gene Expression ◽

Gene Promoters ◽

Acetyl Coa Carboxylase ◽

Acetyl Coa

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Characterization of cross-resistance patterns in acetyl-CoA carboxylase inhibitor resistant wild oat (Avena fatua)

Weed Science ◽

10.1017/s0043174500088925 ◽

1997 ◽

Vol 45 (6) ◽

pp. 750-755 ◽

Cited By ~ 34

Author(s):

Luc Bourgeois ◽

Norm C. Kenkel ◽

Ian N. Morrison

Keyword(s):

Cluster Analysis ◽

Principal Component ◽

Petri Dish ◽

Cross Resistance ◽

Wild Oat ◽

Acetyl Coa Carboxylase ◽

Acetyl Coa ◽

Pairwise Correlation ◽

Resistance Patterns

The purpose of this study was to determine cross-resistance patterns among wild oat lines resistant to acetyl-CoA carboxylase (ACCase) inhibitors and to determine which, if any, cross-resistant type was more common than another. Discriminatory concentrations of two aryloxyphenoxy-propionates (APP) and three cyclohexanediones (CHD) were determined using a petri-dish bioassay. These concentrations were then applied to 82 resistant wild oat lines identified in previous studies. In addition, two resistant standards (UM1 and UM33) and a susceptible standard (UM5) were included in the experiments. Coleoptile lengths expressed as percentages of untreated controls were used to assess the level of resistance to each herbicide. Large variations were observed among wild oat lines and herbicides. However, cluster analysis summarized the relationship between the five herbicides (variables) and the wild oat lines into three main cross-resistance types. Type A included wild oat lines with high resistance to APP herbicides and no or low resistance to CHD herbicides. Types B and C included those with low to moderate resistant and high levels of resistance to all five herbicides, respectively. Type C was the most common cross-resistance type. Relationships among herbicides were determined using pairwise correlation and principal component analysis (PCA). All correlations were high between APP herbicides and between CHD herbicides but not between APP and CHD herbicides. The first two axes of the PCA accounted for 88.4% of the total variance, with the first axis correlated to the CHD herbicides and the second axis correlated to the APP herbicides. In the PCA, wild oat lines were segregated into the three types identified in the cluster analysis. Although CHD and APP herbicides bind at the same region on the ACCase, resistant wild oat lines respond differently to them.

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Purification and characterization of a lectin from Xanthomonas campestris NCIM 5028

Canadian Journal of Microbiology ◽

10.1139/m96-082 ◽

1996 ◽

Vol 42 (6) ◽

pp. 609-612 ◽

Cited By ~ 1

Author(s):

Bhagyashree Joshi ◽

Jayant M. Khire ◽

Hephzibah SivaRaman ◽

M. Islam Khan

Keyword(s):

Molecular Mass ◽

Host Plant ◽

Xanthomonas Campestris ◽

Simple Procedure ◽

Gel Filtration ◽

Purification And Characterization ◽

Ammonium Sulphate Precipitation ◽

Molecular Masses ◽

Lectin Purification

A lectin was isolated from culture filtrates of Xanthomonas campestris NCIM 5028, by a simple procedure of hydrophobic chromatography on phenyl-Sepharose after ammonium sulphate precipitation. The lectin was a heterodimer, with subunit molecular masses of 30 000 and 28 000. Gel filtration on S-300 column, calibrated with markers, showed its molecular mass to be approximately 70 000. Its isoelectric point was 7.2. The agglutination of the rabbit erythrocytes by the lectin was inhibited by fetuin glycopeptides and host plant (Brassica oleracea) extracts.Key words: Xanthomonas campestris, lectin, purification.

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Purification and Characterization of Gentisate 1,2-Dioxygenases from Pseudomonas alcaligenes NCIB 9867 and Pseudomonas putida NCIB 9869

Applied and Environmental Microbiology ◽

10.1128/aem.65.3.946-950.1999 ◽

1999 ◽

Vol 65 (3) ◽

pp. 946-950 ◽

Cited By ~ 46

Author(s):

Yongmei Feng ◽

Hoon Eng Khoo ◽

Chit Laa Poh

Keyword(s):

Pseudomonas Putida ◽

Molecular Mass ◽

Amino Acid Residues ◽

Stability Range ◽

Native Molecular Mass ◽

Heat Stable ◽

A Subunit ◽

Pseudomonas Alcaligenes ◽

Similar Kinetic

ABSTRACT Two 3-hydroxybenzoate-inducible gentisate 1,2-dioxygenases were purified to homogeneity from Pseudomonas alcaligenes NCIB 9867 (P25X) and Pseudomonas putida NCIB 9869 (P35X), respectively. The estimated molecular mass of the purified P25X gentisate 1,2-dioxygenase was 154 kDa, with a subunit mass of 39 kDa. Its structure is deduced to be a tetramer. The pI of this enzyme was established to be 4.8 to 5.0. The subunit mass of P35X gentisate 1,2-dioxygenase was 41 kDa, and this enzyme was deduced to exist as a dimer, with a native molecular mass of about 82 kDa. The pI of P35X gentisate 1,2-dioxygenase was around 4.6 to 4.8. Both of the gentisate 1,2-dioxygenases exhibited typical saturation kinetics and had apparent Km s of 92 and 143 μM for gentisate, respectively. Broad substrate specificities were exhibited towards alkyl and halogenated gentisate analogs. Both enzymes had similar kinetic turnover characteristics for gentisate, with k cat/Km values of 44.08 × 104 s−1 M−1 for the P25X enzyme and 39.34 × 104 s−1M−1 for the P35X enzyme. Higherk cat/Km values were expressed by both enzymes against the substituted gentisates. Significant differences were observed between the N-terminal sequences of the first 23 amino acid residues of the P25X and P35X gentisate 1,2-dioxygenases. The P25X gentisate 1,2-dioxygenase was stable between pH 5.0 and 7.5, with the optimal pH around 8.0. The P35X enzyme showed a pH stability range between 7.0 and 9.0, and the optimum pH was also 8.0. The optimal temperature for both P25X and P35X gentisate 1,2-dioxygenases was around 50°C, but the P35X enzyme was more heat stable than that from P25X. Both enzymes were strongly stimulated by 0.1 mM Fe2+ but were completely inhibited by the presence of 5 mM Cu2+. Partial inhibition of both enzymes was also observed with 5 mM Mn2+, Zn2+, and EDTA.

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Purification and characterization of methionine γ-lyase from Trichomonas vaginalis

Biochemical Journal ◽

10.1042/bj2790675 ◽

1991 ◽

Vol 279 (3) ◽

pp. 675-682 ◽

Cited By ~ 65

Author(s):

B C Lockwood ◽

G H Coombs

Keyword(s):

Molecular Mass ◽

Trichomonas Vaginalis ◽

Protozoan Parasite ◽

Purification And Characterization ◽

Native Molecular Mass ◽

Substrate Analogues ◽

Beta Elimination ◽

Derivatives Of ◽

Methionine Gamma Lyase

Methionine gamma-lyase (EC 4.4.1.11) was purified to homogeneity from the anaerobic protozoan parasite Trichomonas vaginalis by a series of f.p.l.c. procedures. The enzyme catalyses alpha gamma- and alpha beta-elimination reactions of a number of derivatives of methionine and cysteine. It also catalyses gamma-replacement reactions of the thiomethyl group of methionine, homocysteine and ethionine to yield the corresponding S-substituted homocysteine derivative. The enzyme is pyridoxal 5′-phosphate-dependent, has a native molecular mass of approx. 160 kDa and consists of four apparently identical subunits of molecular mass 43-45 kDa. The absorption spectrum of the enzyme is typical of those obtained for other pyridoxal 5′-phosphate-dependent enzymes, and the holoenzyme can be resolved to the apoenzyme by incubation with hydroxylamine and reconstituted by addition of the cofactor. The enzyme activity is significantly affected by carbonyl and thiol reagents, is competitively inhibited by a number of substrate analogues and is completely inactivated by the suicide inhibitor DL-propargylglycine. The T. vaginalis enzyme is similar, in terms of activity and properties, to the enzymes found in a number of species of bacteria that metabolize methionine under anaerobic conditions. It is suggested that methionine catabolism may be of particular importance to the survival of T. vaginalis under microaerophilic conditions in its host.

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