Abstract:SUMMARYFormate dehydrogenase (EC 1.2.1.2) from an aerobic organism was found to be metal-dependent. 1his NAD +-dependent enzyme ~equired the presence of tungsten or molybdenum to express high enzyme levels in the facultative methylotrophic Methylobacterium sp. RXM. The apparent Vm,,x of the reaction increased 22-fold in a tungstate-contaming medium when compared with a non-metal-supplemented growth medium. The absence of those metals in the culture medium resulted in the partial loss of an energyyielding step … Show more
“…This result may be related to observations that high concentrations of tungstate and W-pterin guanidine dinucleotide cofactor intermediates in the pterin pathway can cause cellular toxicity 28 , 29 . Interestingly, optimum concentration of tungstate seems to repress the degradation of recombinant MeFDH1 (Figure S1 of Supplementary Information), which implies that tungstate deficiency may cause improper production of apoprotein, and apoprotein may be more vulnerable to endogenous degradation 30 . Figure 5 Relative expression level of MeFDH1 depending on cofactor (W) concentration and formate productivity in electrochemical CO 2 reduction system (0.6 g wet-cell, 10 mM MV, pH 6.0; CO 2 gas purging (99.999%, rate: 1 mL/s)).…”
The conversion of carbon dioxide to formate is a fundamental step for building C1 chemical platforms. Methylobacterium extorquens AM1 was reported to show remarkable activity converting carbon dioxide into formate. Formate dehydrogenase 1 from M. extorquens AM1 (MeFDH1) was verified as the key responsible enzyme for the conversion of carbon dioxide to formate in this study. Using a 2% methanol concentration for induction, microbial harboring the recombinant MeFDH1 expressing plasmid produced the highest concentration of formate (26.6 mM within 21 hours) in electrochemical reactor. 60 μM of sodium tungstate in the culture medium was optimal for the expression of recombinant MeFDH1 and production of formate (25.7 mM within 21 hours). The recombinant MeFDH1 expressing cells showed maximum formate productivity of 2.53 mM/g-wet cell/hr, which was 2.5 times greater than that of wild type. Thus, M. extorquens AM1 was successfully engineered by expressing MeFDH1 as recombinant enzyme to elevate the production of formate from CO2 after elucidating key responsible enzyme for the conversion of CO2 to formate.
“…This result may be related to observations that high concentrations of tungstate and W-pterin guanidine dinucleotide cofactor intermediates in the pterin pathway can cause cellular toxicity 28 , 29 . Interestingly, optimum concentration of tungstate seems to repress the degradation of recombinant MeFDH1 (Figure S1 of Supplementary Information), which implies that tungstate deficiency may cause improper production of apoprotein, and apoprotein may be more vulnerable to endogenous degradation 30 . Figure 5 Relative expression level of MeFDH1 depending on cofactor (W) concentration and formate productivity in electrochemical CO 2 reduction system (0.6 g wet-cell, 10 mM MV, pH 6.0; CO 2 gas purging (99.999%, rate: 1 mL/s)).…”
The conversion of carbon dioxide to formate is a fundamental step for building C1 chemical platforms. Methylobacterium extorquens AM1 was reported to show remarkable activity converting carbon dioxide into formate. Formate dehydrogenase 1 from M. extorquens AM1 (MeFDH1) was verified as the key responsible enzyme for the conversion of carbon dioxide to formate in this study. Using a 2% methanol concentration for induction, microbial harboring the recombinant MeFDH1 expressing plasmid produced the highest concentration of formate (26.6 mM within 21 hours) in electrochemical reactor. 60 μM of sodium tungstate in the culture medium was optimal for the expression of recombinant MeFDH1 and production of formate (25.7 mM within 21 hours). The recombinant MeFDH1 expressing cells showed maximum formate productivity of 2.53 mM/g-wet cell/hr, which was 2.5 times greater than that of wild type. Thus, M. extorquens AM1 was successfully engineered by expressing MeFDH1 as recombinant enzyme to elevate the production of formate from CO2 after elucidating key responsible enzyme for the conversion of CO2 to formate.
“…When this organism was grown using methanol as the sole carbon source, the addition of Mo or W to the growth medium led to a two-fold increase in the cell yield [227]. In addition, the specific activity of FDH in the cell-free extract increased five-fold when Mo was added and 22-fold if W was present, and in the absence of either element, formate accumulated in the medium [227]. These results clearly suggest that Methylobacterium sp.…”
Section: Aerobic and Facultatively Aerobic Bacteriamentioning
Tungsten (atomic number 74) and the chemically analogous and very similar metal molybdenum (atomic number 42) are minor yet equally abundant elements on this planet. The essential role of molybdenum in biology has been known for decades and molybdoenzymes are ubiquitous. Yet, it is only recently that a biological role for tungsten has been established in prokaryotes, although not as yet in eukaryotes. The best characterized organisms with regard to their metabolism of tungsten are certain species of hyperthermophilic archaea (Pyrococcus furiosus and Thermococcus litoralis), methanogens (Methanobacterium thermoautotrophicum and Mb. wolfei), Gram-positive bacteria (Clostridium thermoaceticum, C. formicoaceticum and Eubacterium acidaminophilum), Gram-negative anaerobes (Desulfovibrio gigas and Pelobacter acetylenicus) and Gram-negative aerobes (Methylobacterium sp. RXM). Of these, only the hyperthermophilic archaea appear to be obligately tungsten-dependent. Four different types of tungstoenzyme have been purified: formate dehydrogenase, formyl methanofuran dehydrogenase, acetylene hydratase, and a class of phylogenetically related oxidoreductases that catalyze the reversible oxidation of aldehydes. These are carboxylic reductase, and three ferredoxin-dependent oxidoreductases which oxidize various aldehydes, formaldehyde and glyceraldehyde 3-phosphate. All tungstoenzymes catalyze redox reactions of very low potential (< -420 mV) except one (acetylene hydratase) which catalyzes a hydration reaction. The tungsten in these enzymes is bound by a pterin moiety similar to that found in molybdoenzymes. The first crystal structure of a tungsten-or pterin-containing enzyme, that of aldehyde ferredoxin oxidoreductase from P. furiosus, has revealed a catalytic site with one W atom coordinated to two pterin molecules which are themselves bridged by a magnesium ion. The geochemical, ecological, biochemical and phylogenetic basis for W-vs. Mo-dependent organisms is discussed.
“…Notably, the structures of two molybdoenzymes have subsequently been determined. , Thus, for the first time, direct comparisons at the atomic level between these two classes of enzyme are now possible. Moreover, in addition to acetogens, methanogens, and hyperthermophiles, tungstoenzymes have been purified from acetylene-utilizing and sulfate-reducing anaerobes, and although not purified, a tungstoenzyme appears to be present in some aerobic, methylotrophic organisms. , …”
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
