Structure based protein engineering of aldehyde dehydrogenase from Azospirillum brasilense to enhance enzyme activity against unnatural 3-hydroxypropionaldehyde

2021 ◽  
Author(s):  
Hyeoncheol Francis Son ◽  
Kyung-Jin Kim
Keyword(s):  
Enzyme Activity ◽  
Protein Engineering ◽  
Aldehyde Dehydrogenase ◽  
Azospirillum Brasilense

scholarly journals Conversion of Waste Agriculture Biomass to Bioethanol by Recombinant Saccharomyces cerevisiae

2010 ◽  
Vol 2 (2) ◽  
pp. 351-361
Author(s):  
A. A. Saleh ◽  
S. Hamdan ◽  
N. Annaluru ◽  
S. Watanabe ◽  
M. R. Rahman ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Enzyme Activity ◽  
Protein Engineering ◽  
Agricultural Waste ◽  
Xylitol Dehydrogenase ◽  
Ethanol Conversion ◽  
Waste Biomass ◽  
Wild Type ◽  
Coenzyme Specificity ◽  
Recombinant Yeasts

Agricultural waste biomass has already been transferred to bioethanol and used as energy related products, although many issues such as efficiency and productivity still to be overcome. In this study, the protein engineering was applied to generate enzymes with completely reversed coenzyme specificity and developed recombinant yeasts containing those engineered enzymes for construction of an efficient biomass-ethanol conversion system. Recombinant yeasts were constructed with the genes encoding a wild type xylose reductase (XR) and the protein engineered xylitol dehydrogenase (XDH) (with NADP) of Pichia stipitis.  These recombinant yeasts were characterized based on the enzyme activity and fermentation ability of xylose to ethanol. The protein engineered enzymes were expressed significantly in Saccharomyces cerevisiae as judged by the enzyme activity in vitro. Ethanol fermentation was measured in batch culture under anaerobic conditions. The significant enhancement was found in Y-ARS strain, in which NADP+-dependent XDH was expressed; 85% decrease of unfavorable xylitol excretion with 26% increased ethanol production, when compared with the reference strain expressing the wild-type XDH.  Keywords: Agricultural waste biomass; Protein engineering; Xylitol dehydrogenase; Xylose-fermentation; Eethanol production. © 2010 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v2i2.2882               J. Sci. Res. 2 (2), 351-361 (2010) 

Effect of Soil Salinity on the Expression of Betaine Aldehyde Dehydrogenase in Leaves: Investigation of Hydraulic, Ionic and Biochemical Signals.

1992 ◽  
Vol 19 (5) ◽  
pp. 555 ◽  
Author(s):  
KF Mccue ◽  
AD Hanson
Keyword(s):  
Enzyme Activity ◽  
Aldehyde Dehydrogenase ◽  
Half Life ◽  
Mrna Level ◽  
State Level ◽  
Betaine Aldehyde Dehydrogenase ◽  
Mrna Levels ◽  
Betaine Aldehyde ◽  
Hydraulic Signal ◽  
Leaf Disks

Betaine aldehyde dehydrogenase (BADH) catalyses the last step in glycine betaine synthesis. The levels of BADH enzyme and BADH mRNA have previously been shown to be increased several-fold by salt stress. To characterise this induction more thoroughly, BADH mRNA levels and enzyme activities were analysed in leaves of sugar beet plants (Beta vulgaris L.) subjected to different salinisation regimes. Following a salt shock (transfer from 0 to 400 mM NaCI) BADH enzyme activity rose slowly for several days. In contrast, BADH mRNA level first decreased for several hours, and then increased. When salt was leached from the rooting medium of salinised plants, BADH enzyme activity declined, with a half-life of more than 4 days. However, the level of BADH mRNA declined sharply with an apparent half-life of 2 h showing that transcription of the BADH gene or the stability of BADH mRNA in leaves can respond very dynamically to salinity changes around the root. In plants which had been gradually salinised and then held at various NaCl concentrations, the steady state level of enzyme rose continuously between 0 and 500 mM NaCl, whereas that of BADH mRNA reached a plateau at 100 mM NaCl. In general, the observed BADH mRNA fluctuations could not be satisfactorily explained by assuming them to be responses to hydraulic signals. This suggests the participation of a non-hydraulic signal or signals coming from the root. The non-hydraulic signal is unlikely to be NaCl, because leaf disks exposed to salt concentrations typical of the apoplast of salinised leaves did not accumulate BADH mRNA. A biochemical messenger is thus implied. Although abscisic acid application to leaf disks elicited significant increases in BADH mRNA level, these were several-fold smaller than those observed in leaves of intact salinised plants, suggesting the involvement of some other substance.

scholarly journals The activation of aldehyde dehydrogenase by diethylstilboestrol and 2,2′-dithiodipyridine

1982 ◽  
Vol 207 (1) ◽  
pp. 81-89 ◽  
Author(s):  
T M Kitson
Keyword(s):  
Enzyme Activity ◽  
Aldehyde Dehydrogenase ◽  
Human Liver ◽  
Common Property ◽  
Rabbit Liver ◽  
Aldehyde Dehydrogenases ◽  
Cytoplasmic Enzyme ◽  
Sheep Liver ◽  
Low Concentrations ◽  
Liver Aldehyde Dehydrogenase

1. The activation of sheep liver cytoplasmic aldehyde dehydrogenase by diethylstilboestrol and by 2,2′-dithiodipyridine is described. The effects of the two modifiers are very similar with respect to variation with acetaldehyde concentration, pH and temperature. Thus the degree of activation is maximal when the enzyme is assayed at approx. 1 mM-acetaldehyde, is greater at 25 degrees C than at 37 degrees C, and is greater at pH 7.4 than at pH 9.75. With low concentrations of acetaldehyde both modifiers decrease the enzyme activity. 2. Diethylstilboestrol affects the sheep liver cytoplasmic enzyme in a very similar way to that previously described for a rabbit liver cytoplasmic enzyme. Preliminary experiments show that the same is true for a preparation of human liver aldehyde dehydrogenase. It is proposed that sensitivity to diethylstilboestrol (and steroids) is a common property of all mammalian cytoplasmic aldehyde dehydrogenases.

scholarly journals Correlation of loss of activity of human aldehyde dehydrogenase with reaction of bromoacetophenone with glutamic acid-268 and cysteine-302 residues. Partial-sites reactivity of aldehyde dehydrogenase

1990 ◽  
Vol 266 (1) ◽  
pp. 179-187 ◽  
Author(s):  
D P Abriola ◽  
A D MacKerell ◽  
R Pietruszko
Keyword(s):  
Enzyme Activity ◽  
Glutamic Acid ◽  
Aldehyde Dehydrogenase ◽  
Scintillation Counting ◽  
Radioactive Label ◽  
Affinity Reagent ◽  
Activity Loss

Bromoacetophenone (2-bromo-1-phenylethanone) has been characterized as an affinity reagent for human aldehyde dehydrogenase (EC 1.2.1.3) [MacKerell, MacWright & Pietruszko (1986) Biochemistry 25, 5182-5189], and has been shown to react specifically with the Glu-268 residue [Abriola, Fields, Stein, MacKerell & Pietruszko (1987) Biochemistry 26, 5679-5684] with an apparent inactivation stoichiometry of two molecules of bromoacetophenone per molecule of enzyme. The specificity of bromoacetophenone for reaction with Glu-268, however, is not absolute, owing to the extreme reactivity of this reagent. When bromo[14C]acetophenone was used to label the human cytoplasmic E1 isoenzyme radioactively and tryptic fragmentation was carried out, peptides besides that containing Glu-268 were found to have reacted with reagent. These peptides were purified by h.p.l.c. and analysed by sequencing and scintillation counting to quantify radioactive label in the material from each cycle of sequencing. Reaction of bromoacetophenone with the aldehyde dehydrogenase molecule during enzyme activity loss occurs with two residues, Glu-268 and Cys-302. The activity loss, however, appears to be proportional to incorporation of label at Glu-268. The large part of incorporation of label at Cys-302 occurs after the activity loss is essentially complete. With both Glu-268 and Cys-302, however, the incorporation of label stops after one molecule of bromoacetophenone has reacted with each residue. Reaction with other residues continues after activity loss is complete.

scholarly journals Arthrobacter d-xylose isomerase: chemical modification of carboxy groups and protein engineering of pH optimum

1993 ◽  
Vol 296 (3) ◽  
pp. 685-691 ◽  
Author(s):  
K S Siddiqui ◽  
T Loviny-Anderton ◽  
M Rangarajan ◽  
B S Hartley
Keyword(s):  
Enzyme Activity ◽  
Protein Engineering ◽  
Coupling Reaction ◽  
Xylose Isomerase ◽  
Kinetic Studies ◽  
Exchange Chromatography ◽  
Water Soluble ◽  
Native Enzyme ◽  
Ph Optimum ◽  
Isomerase Activity

To try to lower the pH optimum, the carboxy groups of Arthrobacter D-xylose isomerase were coupled to glycinamide using a water-soluble carbodi-imide. In conditions that substituted all of the 59 carboxy groups in the denatured monomer, a maximum of 30 groups/monomer reacted in the native enzyme, whether in presence or absence of ligands, and the enzyme remained fully active and tetrameric throughout the coupling reaction. Purification by f.p.l.c. ion-exchange chromatography gave broad symmetrical peaks with increased pI, suggesting that the modified enzymes are essentially homogeneous. However, they are less stable than native enzyme in 8 M urea or on heating (‘melting points’ of 59 degrees versus 73 degrees C for the apoenzymes and 67 degrees versus 81.5 degrees C for the Mg(2+)-enzymes). Kinetic studies of the D-fructose isomerase activity at 30 degrees C showed that the glycinamidylated enzyme had unaltered activation constant for Mg2+, and Km was also similar to that of the native enzyme at pH 7.3, but increased rapidly at higher pH rather than remaining constant. Vmax. was constant from pH 6.2 to 8.0, suggesting a reduced pKa for His-219, which controls Vmax. in the native enzyme (normally 6.0). Three mutants were constructed by protein engineering with a view to reducing the pH optimum of enzyme activity. Two of these, Glu140→Lys and Asp189→Lys, could be detected in crude extracts of Escherichia coli by SDS/PAGE, but could not be purified, whereas mutant Trp136→Glu was produced as a tetramer in amounts similar to the wild-type enzyme. However, it did not show any enzyme activity and was less stable in 0-9 M urea gradient PAGE.

scholarly journals Characterization of glutamine synthetase from the ammonium-excreting strain HM053 of Azospirillum brasilense

2022 ◽  
Vol 82 ◽  
Author(s):  
Fernanda Ghenov ◽  
Edileusa Cristina Marques Gerhardt ◽  
Luciano Fernandes Huergo ◽  
Fabio Oliveira Pedrosa ◽  
Roseli Wassem ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Glutamine Synthetase ◽  
Affinity Chromatography ◽  
Azospirillum Brasilense ◽  
Nitrogen Assimilation ◽  
Atp Hydrolysis ◽  
Nitrogen Fixing ◽  
Wild Type ◽  
E Coli

Abstract Glutamine synthetase (GS), encoded by glnA, catalyzes the conversion of L-glutamate and ammonium to L-glutamine. This ATP hydrolysis driven process is the main nitrogen assimilation pathway in the nitrogen-fixing bacterium Azospirillum brasilense. The A. brasilense strain HM053 has poor GS activity and leaks ammonium into the medium under nitrogen fixing conditions. In this work, the glnA genes of the wild type and HM053 strains were cloned into pET28a, sequenced and overexpressed in E. coli. The GS enzyme was purified by affinity chromatography and characterized. The GS of HM053 strain carries a P347L substitution, which results in low enzyme activity and rendered the enzyme insensitive to adenylylation by the adenilyltransferase GlnE.

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