Reversible immobilization of molybdenum cofactor on a gel matrix via sulphydryl groups

Mendel, Ralf R.; Alikulov, Z.A

doi:10.1016/s0021-9673(01)90862-3

Cited by 13 publications

(5 citation statements)

References 4 publications

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“…The presence of thiols in bactopterin was suggested by its affinity to Thiol-Sepharose and elution by reduced thiol reagents (unpub- lished data). From similar experiments, the presence of thiols in molybdopterin has been concluded [50]. It has been established that CO dehydrogenases contain a MoCo which complements aponitrate reductase with the same efficiency as do other molybdoenzymes [4,7,8,12,31].…”

Section: Bactopterinmentioning

confidence: 84%

“…This explains why MoCo does not exist stably in a free and soluble state unless special precautions are taken. On the other hand, it was relatively stable when kept under anaerobic and reducing conditions [46][47][48][49] or in the presence of thiol reagents [50].…”

Section: Molybdenum Cofactormentioning

confidence: 99%

“…In active molybdopterin the Mo atom is chelated by the thiols. Further support for the presence of thiols in molybdopterin was provided by the binding of native molybdopterin to Thiol-Sepharose [50], the presence of a thiophene ring in one of the oxidized derivatives (form B) [55,56], the inactivation of molybdopterin by thiol reagents [49,53] and analysis of sulfur by EDAX [49]. It can be expected that chemical and spectroscopic investigations will provide direct evidence for the double bond postulated between C-I and C-2 of the side chain.…”

Section: Molybdopterinmentioning

confidence: 99%

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Biochemistry and physiology of aerobic carbon monoxide-utilizing bacteria

Meyer

Jacobitz

Krüger

1986

FEMS Microbiology Letters

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The use of CO as a growth substrate by aerobic CO‐oxidizing (carboxydotrophic) bacteria requires some features not obvious in other bacteria. These are the presence of the enzyme CO dehydrogenase, a branched respiratory chain with an alternative CO‐insensitive terminal oxidase (cytochrome b653) and formation of reduced pyridine nucleotides by a pmf‐driven reversed electron transfer. Immunocytochemical localization studies revealed that CO dehydrogenase is attached to the inner aspect of the cytoplasmic membrane of Pseudomonas carboxydovorans. The enzyme is a molybdo iron‐sulfur flavoprotein containing bactopterin as the organic portion of the molybdenum cofactor. Recent findings suggest that this novel pterin is universal to eubacterial molybdenum enzymes, whereas molybdopterin is universal to eukaryotic molybdoenzymes.

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Section: Bactopterinmentioning

confidence: 84%

Section: Molybdenum Cofactormentioning

confidence: 99%

Section: Molybdopterinmentioning

confidence: 99%

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Biochemistry and physiology of aerobic carbon monoxide-utilizing bacteria

Meyer

Jacobitz

Krüger

1986

FEMS Microbiology Letters

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“…Expression of a recombinant BSO reductase as a GST fusion protein presented several potential advantages for the production of a functional molybdoprotein. First, the system allowed the affinity purification of the BSO reductase under reducing conditions which could be important when cells are broken by sonication to prevent damage of the Mo cofactor due to oxidation by free radicals, while second, glutathione-agarose has previously been used to isolate an active form of the Mo cofactor from xanthine oxidase under reducing conditions (Mendel and Alikulov, 1983) and therefore may stabilize the functional forms of Mo-containing enzymes during purification.…”

Section: Discussionmentioning

confidence: 99%

Biotin Sulfoxide Reductase

Pollock

Barber

1997

Journal of Biological Chemistry

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Rhodobacter sphaeroides f. sp. denitrificans biotin sulfoxide reductase has been heterologously expressed in Escherichia coli as a functional 106-kDa glutathione S-transferase fusion protein. Following cleavage with Factor Xa and purification to homogeneity, the soluble 83-kDa enzyme retained biotin sulfoxide reductase activity using reduced methyl viologen or reduced benzyl viologen as artificial electron donors. Initial rate kinetics indicated a specific activity at pH 8.0 of 0.9 mol of biotin sulfoxide reduced per min/nmol of enzyme and K m values of 29 and 15 M for reduced methyl viologen and biotin sulfoxide reductase, respectively. Biotin sulfoxide reductase was also capable of reducing nicotinamide N-oxide, methionine sulfoxide, trimethylamine-N-oxide, and dimethyl sulfoxide, although with varying efficiencies, and could directly utilize NADPH as a reducing agent, both for the reduction of biotin sulfoxide and ferricyanide. The enzyme contained the prosthetic group, molybdopterin guanine dinucleotide, and did not require any accessory proteins for functionality. These results represent the first successful heterologous expression and characterization of a functional molybdopterin guanine dinucleotide-containing enzyme and the demonstration of reduced pyridine nucleotide-dependent biotin sulfoxide reductase activity.Biotin sulfoxide (BSO) 1 reductase, which catalyzes the reduction of d-biotin d-sulfoxide to d-biotin according to the following scheme,has been postulated to function in a variety of roles in bacterial metabolism (Pierson and Campbell, 1990) including scavenging biotin sulfoxide from the environment and thus allowing bacteria to utilize this oxidized form of biotin for biosynthetic reactions: reducing bound intracellular biotin, such as bound to biotin-containing carboxylases or protein degradation products, that have become oxidized in aerobic environments; or as a potential protector of the cell from oxidative damage similar to the proposed roles of methionine sulfoxide reductase (Ejiri et al., 1980;Brot et al., 1981;Rahman et al., 1992) and superoxide dismutase (Fridovich, 1989).BSO reductase has been partially purified from Escherichia coli and demonstrated to be a soluble protein that requires an unidentified form of the Mo cofactor (Rajagopalan and Johnson, 1992) and several accessory proteins for activity (del CampilloCampbell and Campbell, 1982). These accessory proteins include a small, heat stable, thioredoxin-like protein moiety, referred to as protein-(SH) 2 and which functions as a source of reducing equivalents and an unidentified flavoprotein (del Campillo-Campbell et al., 1979). The extensive characterization of BSO reductase has been limited by the low natural abundance of the protein, its constitutive expression, and the requirement for auxiliary proteins for activity coupled with the difficulty of its detection in the absence of specific antibodies. While the E. coli BSO reductase bisC structural gene has been cloned and sequenced, the enzyme has not been produced using hete...

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“…The presence of a dithiolene group in MPT would be expected to contribute to the extreme lability of the molecule [40]. It therefore seemed probable that isolation of a stable MPT derivative retaining both sulfur atoms would require attenuation of the reactivity of the thiol groups [9].…”

Section: The Discovery Of Mocomentioning

confidence: 99%

The history of the discovery of the molybdenum cofactor and novel aspects of its biosynthesis in bacteria

Leimkühler

Wuebbens

Rajagopalan

2011

Coordination Chemistry Reviews

121

154

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Biosynthesis of the molybdenum cofactor in bacteria is described with a detailed analysis of each individual reaction leading to the formation of stable intermediates during the synthesis of molybdopterin from GTP. As a starting point, the discovery of molybdopterin and the elucidation of its structure through the study of stable degradation products are described. Subsequent to molybdopterin synthesis, the molybdenum atom is added to the molybdopterin dithiolene group to form the molybdenum cofactor. This cofactor is either inserted directly into specific molybdoenzymes or is further modified by the addition of nucleotides to the molybdopterin phosphate group or the replacement of ligands at the molybdenum center.

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Reversible immobilization of molybdenum cofactor on a gel matrix via sulphydryl groups

Cited by 13 publications

References 4 publications

Biochemistry and physiology of aerobic carbon monoxide-utilizing bacteria

Biochemistry and physiology of aerobic carbon monoxide-utilizing bacteria

Biotin Sulfoxide Reductase

The history of the discovery of the molybdenum cofactor and novel aspects of its biosynthesis in bacteria

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