Stabilizing effect of chemical additives against oxidation of lactate dehydrogenase

Andersson, Maria; Breccia, Javier D.; Hatti‐Kaul, Rajni

doi:10.1042/ba20000014

Cited by 80 publications

(51 citation statements)

References 36 publications

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“…In silico analysis of the Ϫ10 and Ϫ35 sequences of these regions showed that ectAp1 and ectAp2 may be dependent on the main vegetative factor 70 , whereas ectAp3 and ectBp were similar to S -and 32 -dependent promoters, respectively. In agreement with these predictions, expression of an ectAp (1)(2)(3)(4)::lacZ fusion was osmoregulated and depended in part on the general stress factor S , whereas ectBp was induced by continuous growth at a high temperature. Very interestingly, expression from ectAp was reduced when excess iron (50 M FeCl 3 ) was added to the medium, suggesting that there is a regulatory link between iron homeostasis and the osmostress response in C. salexigens (11).…”

supporting

confidence: 66%

“…Hydroxyectoine was able to protect lactate dehydrogenase from metal-catalyzed oxidation (2) and to protect plasmid DNA from damage by a number of OH radical-producing systems, including 0.1 mM FeCl 3 (45). Therefore, our interpretation is that this is a way for C. salexigens to respond to the oxidative stress imposed by excess iron (50 M FeCl 3 ).…”

Section: Discussionmentioning

confidence: 82%

“…Compared to the expression in the wild type, the steady-state level of ectA expression in the fur mutant was similar in cells grown at low salinity, but it was 10-fold lower in cells grown with 2.5 M NaCl, suggesting that Fur functions as a positive regulator of the ectABC genes under high-salt conditions. As previously described by Calderón et al (11) using a ectAp (1)(2)(3)(4)::lacZ fusion, ectA expression was downregulated by excess iron in wild-type cells grown with 0.75 M NaCl. The repression was even greater (the levels were 5-fold lower than the levels under low-iron conditions) in cells grown at high salinity (Fig.…”

mentioning

confidence: 94%

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Interplay between Iron Homeostasis and the Osmotic Stress Response in the Halophilic Bacterium Chromohalobacter salexigens

Argandoña¹,

Nieto²,

Iglesias‐Guerra

et al. 2010

Appl Environ Microbiol

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In this study, the connection between iron homeostasis and the osmostress response in the halophile Chromohalobacter salexigens was investigated. A decrease in the requirement for both iron and histidine and a lower level of siderophore synthesis were observed at high salinity, and these findings were correlated with a lower protein content in salt-stressed cells. A six-gene operon (cfuABC-fur-hisI-orf6 operon) located downstream of the ectABC ectoine synthesis genes was characterized. A fur strain (in which the ferric iron uptake regulator Fur was affected) had the Mn resistance phenotype typical of fur mutants, was deregulated for siderophore production, and displayed delayed growth under iron limitation conditions, indicating that fur encodes a functional iron regulator. hisI was essential for histidine synthesis, which in turn was necessary for siderophore production. Fur boxes were found in the promoters of the cfuABC-fur-hisI-orf6 and ectABC operons, suggesting that Fur directly interacts with DNA in these regions. Fur mediated the osmoregulated inhibition of cfuABC-fur-hisI-orf6 operon expression by iron and functioned as a positive regulator of the ectABC genes under high-salinity conditions, linking the salt stress response with iron homeostasis. Excess iron led to a higher cytoplasmic hydroxyectoine content, suggesting that hydroxyectoine protects against the oxidative stress caused by iron better than ectoine. This study provides the first evidence of involvement of the iron homeostasis regulator Fur as part of the complex circuit that controls the response to osmotic stress in halophilic bacteria.

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supporting

confidence: 66%

Section: Discussionmentioning

confidence: 82%

mentioning

confidence: 94%

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Interplay between Iron Homeostasis and the Osmotic Stress Response in the Halophilic Bacterium Chromohalobacter salexigens

Argandoña¹,

Nieto²,

Iglesias‐Guerra

et al. 2010

Appl Environ Microbiol

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“…Porcine muscle lactate dehydrogenase was submitted to oxidation in the presence of metal ions and hydrogen peroxide, in the presence of a variety of compounds [211]. The best protecting agent was found to be the poly(ethyleneimine), followed by EDTA.…”

Section: Keeping Hydrogen Peroxide Concentration At Low Levelsmentioning

confidence: 99%

Hydrogen Peroxide in Biocatalysis. A Dangerous Liaison

Hernández

Berenguer-Murcia²,

Rodrigues³

et al. 2012

COC

140

107

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Hydrogen peroxide is a substrate or side-product in many enzyme-catalyzed reactions. For example, it is a side-product of oxidases, resulting from the re-oxidation of FAD with molecular oxygen, and it is a substrate for peroxidases and other enzymes. However, hydrogen peroxide is able to chemically modify the peptide core of the enzymes it interacts with, and also to produce the oxidation of some cofactors and prostetic groups (e.g., the hemo group). Thus, the development of strategies that may permit to increase the stability of enzymes in the presence of this deleterious reagent is an interesting target. This enhancement in enzyme stability has been attempted following almost all available strategies: site-directed mutagenesis (eliminating the most reactive moieties), medium engineering (using stabilizers), immobilization and chemical modification (trying to generate hydrophobic environments surrounding the enzyme, to confer higher rigidity to the protein or to generate oxidation-resistant groups), or the use of systems capable of decomposing hydrogen peroxide under very mild conditions. If hydrogen peroxide is just a side-product, its immediate removal has been reported to be the best solution. In some cases, when hydrogen peroxide is the substrate and its decomposition is not a sensible solution, researchers coupled one enzyme generating hydrogen peroxide "in situ" to the target enzyme resulting in a continuous supply of this reagent at low concentrations thus preventing enzyme inactivation.This review will focus on the general role of hydrogen peroxide in biocatalysis, the main mechanisms of enzyme inactivation produced by this reactive and the different strategies used to prevent enzyme inactivation caused by this "dangerous liaison". Outlook

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“…Hydroxyectoine has previously been reported to modestly improve survival of freeze-dried E. coli (23). It can also protect susceptible enzymes against desiccation and other stresses in vitro (1,22), although other authors have shown that hydroxyectoine inhibits certain enzyme activities and DNA-protein complex formation (25), implying a potentially negative impact on metabolism.…”

Section: Discussionmentioning

confidence: 99%

Hydroxyectoine Is Superior to Trehalose for Anhydrobiotic Engineering of Pseudomonas putida KT2440

Manzanera

Castro

Tøndervik

et al. 2002

Appl Environ Microbiol

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Anhydrobiotic engineering aims to increase the level of desiccation tolerance in sensitive organisms to that observed in true anhydrobiotes. In addition to a suitable extracellular drying excipient, a key factor for anhydrobiotic engineering of gram-negative enterobacteria seems to be the generation of high intracellular concentrations of the nonreducing disaccharide trehalose, which can be achieved by osmotic induction. In the soil bacterium Pseudomonas putida KT2440, however, only limited amounts of trehalose are naturally accumulated in defined high-osmolarity medium, correlating with relatively poor survival of desiccated cultures. Based on the enterobacterial model, it was proposed that increasing intracellular trehalose concentration in P. putida KT2440 should improve survival. Using genetic engineering techniques, intracellular trehalose concentrations were obtained which were similar to or greater than those in enterobacteria, but this did not translate into improved desiccation tolerance. Therefore, at least for some populations of microorganisms, trehalose does not appear to provide full protection against desiccation damage, even when present at high concentrations both inside and outside the cell. For P. putida KT2440, it was shown that this was not due to a natural limit in desiccation tolerance since successful anhydrobiotic engineering was achieved by use of a different drying excipient, hydroxyectoine, with osmotically preconditioned bacteria for which 40 to 60% viability was maintained over extended periods (up to 42 days) in the dry state. Hydroxyectoine therefore has considerable potential for the improvement of desiccation tolerance in sensitive microorganisms, particularly for those recalcitrant to trehalose.Disaccharides and other polyols have been shown to be highly effective stabilizers of dried biological molecules and membranes in vitro, and the protection conferred by trehalose, in particular, has attracted considerable attention (7, 9, 10). Trehalose is also thought to be crucial for the survival of many anhydrobiotic organisms, which are able to maintain viability throughout long periods in a dried state (reviewed in reference 8). It is therefore reasonable to suppose that trehalose (or related molecules, such as sucrose) could be used to improve the desiccation tolerance of otherwise sensitive organisms, and several groups have demonstrated this for microorganisms (2,17,21,23,37).However, the stability of the dried bacteria in these experiments falls far short of that observed in anhydrobiotic organisms. For example, Louis et al. (23) showed that Escherichia coli loses between 1 and 4 logs of viability 6 weeks after being dried in 0.5 M trehalose and stored at 4°C. Welsh and Herbert (37) reported maximal survival rates of 4.2 and 6.5% of initial CFU after 50 days at ambient temperature when E. coli was dried in the presence of 0.25 M extracellular trehalose or with a similar concentration of intracellular trehalose, respectively. Billi et al. (2) genetically engineered E. coli to pr...

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Stabilizing effect of chemical additives against oxidation of lactate dehydrogenase

Cited by 80 publications

References 36 publications

Interplay between Iron Homeostasis and the Osmotic Stress Response in the Halophilic Bacterium Chromohalobacter salexigens

Interplay between Iron Homeostasis and the Osmotic Stress Response in the Halophilic Bacterium Chromohalobacter salexigens

Hydrogen Peroxide in Biocatalysis. A Dangerous Liaison

Hydroxyectoine Is Superior to Trehalose for Anhydrobiotic Engineering of Pseudomonas putida KT2440

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