[41] Isolation, preparation, and assay of pyrroloquinoline quinone

Meer, Robert A. van der; Groen, Barend W.; Kleef, M.A.G. van; Frank, Johannes; Jongejan, Jaap A.; Duine, J. A.

doi:10.1016/0076-6879(90)88043-a

Cited by 47 publications

(30 citation statements)

References 39 publications

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“…1 ) (further reduction to PQQH, is possible [40], but this seems to be an unnatural compound). The reduced forms are unstable under physiological conditions (except when enzyme-bound) : under aerobic conditions, PQQH, is relatively insensitive to 0, oxidation only at low pH; PQQH' (which can be formed from comproportionation of PQQ and PQQH, or by pulse radiolysis of a PQQ solution [441) is only stable at high pH and anaerobic conditions [45].…”

Section: Structure Und Reactivitymentioning

confidence: 99%

“…Although a linear relationship exists between the dye formed and the amount of PQQ added, the method is not selective, and is thus unreliable, since other biochemicals are also active [36]. In this respect, the bio-assays, based on reconstitution of apo-quinoprotein dehydrogenases [40], should be recommended as they are specific and very sensitive. Using samples from plants and animals in which high amounts of PQQ are found with the redox-cycling assay, negative results were obtained with a bio-assay [36].…”

Section: Detection and Quantijicationmentioning

confidence: 99%

“…The method of Corey and Tramontano [74] has been further elaborated in our laboratory in order to develop a process at the 100-g scale [40]. The preparation of specifically labelled (2H, I3C) PQQ and of PQQ analogues has been described [75].…”

Section: Chemical Synthesismentioning

confidence: 99%

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Quinoproteins: enzymes containing the quinonoid cofactor pyrroloquinoline quinone, topaquinone or tryptophan‐tryptophan quinone

Duine¹

1991

European Journal of Biochemistry

197

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The presently best known and largest group of quinoproteins consists of enzymes using the cofactor 2,7,9-tricarboxy-1 H-pyrrolo[2,3-S]quinoline-4,5-dione (PQQ), a compound having a pyrrole ring fused to a quinoline ring with an o-quinone group in it. Representatives of this group are found among the bacterial, NAD(P)-independent, periplasmic dehydrogenases. Despite their high midpoint redox potential, the overall behaviour of quinoprotein dehydrogenases is similar to that of their counterparts, those using a flavin cofactor or a nicotinamide coenzyme. Apart from an exceptional Gram-positive one, the sole organisms where the presence of PQQ has really been established are Gram-negative bacteria. Evidence for the occurrence of covalently bound PQQ is lacking since it has now been shown that several enzymes previously considered to contain this prosthetic group do not in fact do so.Another group of quinoproteins, consisting of amine oxidoreductases, has a protein chain containing one of the following quinonoid aromatic amino acids: 6-hydroxy-phenylalanine-3,4-dione (TPQ) or 4-(2'-tryptophy1)-tryptophan-6,7-dione (TTQ). There is no doubt that these o-quinones play a role as cofactor, in the case of TPQ in prokaryotic as well as eukaryotic amine oxidases. It appears, therefore, that a novel class of amino-acid-derived cofactors is emerging, ranging from the free radical form of tyrosine and tryptophan to those containing a dicarbonyl group (like the already known pyryvoyl group and the o-quinones here described). THE QUINONOID COFACTORS IdentificationAbout ten years ago, the structure of the cofactor of methanol dehydrogenase (EC 1.1.99.8) was elucidated [l, 21. The compound (Fig. 1) has been given the names of pyrroloquinoline quinone (PQQ) and methoxatin. Since it appeared that many other dehydrogenases from Gram-negaCorrespondence to J. A. Duine, Department of Microbiology and Enzymology, Delft University of Technology, Julianalaan 67, NL-2628 BC Delft, The NetherlandsAbbreviations. PQQ, pyrroloquinoline quinone, 2,7,9-tricarboxy-1 H-pyrr010[2,3~/]quinoline-4,5-dione; PQQH', PQQH,, PQQH,, the one-, two-, and four-electron reduced forms of PQQ; PQQ-H20, PQQ with covalently bound H 2 0 at the C5 position; PQ, pyrroloquinoline, 2,7,9-tricarboxy-1H-pyrrolo[2,3-flquinoline; TPQ, topaquinone, 6-hydroxy-phenylalanine-3,4-dione; TTQ, tryptophan-tryptophan quinone, 4-(2'-tryptophyl)-tryptophan-6,7-dione.Enzvmes. tive bacteria contain this cofactor, in analogy with the usual terminology in enzymology (e.g. flavoproteins, haemoproteins) the name quinoproteins was introduced for these enzymes [2]. During the past decade, much has already been revealed of this novel branch of enzymology, as demonstrated in a number of reviews on PQQ [3, 41 and quinoproteins [5, 61, and in the proceedings of the first international symposium on this topic [7].About five years ago, the presence of covalently bound PQQ in copper-containing plasma amine oxidase (EC 1.4.3.6) was reported, as was concluded from the detection of PQQ after acid hyd...

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Section: Structure Und Reactivitymentioning

confidence: 99%

Section: Detection and Quantijicationmentioning

confidence: 99%

See 1 more Smart Citation

Quinoproteins: enzymes containing the quinonoid cofactor pyrroloquinoline quinone, topaquinone or tryptophan‐tryptophan quinone

Duine¹

1991

European Journal of Biochemistry

197

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“…PQQ was synthesized as described previously [7]. 3-Methyl-PQQ and 3-propyl-PQQ were prepared by a similar procedure.…”

Section: Methodsmentioning

confidence: 99%

“…cm-' at 249 nm was used (at pH 4) for PQQ [7]. Iron contents were determined by neutron activation analysis [18].…”

Section: Methodsmentioning

confidence: 99%

Quinohaemoprotein Ethanol Dehydrogenase from Comamonas testosteroni

Jong

Geerlof

Stoorvogel

et al. 1995

European Journal of Biochemistry

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Pyrroloquinoline-quinone(PQQ)-free quinohaemoprotein ethanol dehydrogenase (QH-EDH) apoenzyme was isolated from ethanol-grown Comamonas testosteroni. The purified apoenzyme, showing a single band of 71 kDa on native gel electrophoresis, could be only partially converted into active holoenzyme by addition of PQQ in the presence of calcium ions. In addition to a band with a molecular mass of 71 kDa, additional bands of 51 kDa and 25 kDa were observed with SDSPAGE. Analysis of the Nterminal sequences of the bands and comparison with the DNA sequence of the gene, suggested that the latter two originate from the former one, due to scission occumng at a specific site between two vicinal residues in the protein chain. The extent of scission appeared to increase during growth of the organism. After addition of PQQ to apoenzyme, holoenzyme and nicked, inactive enzyme could he separated. Holoenzyme prepared in this way was found to contain equimolar amounts of PQQ, Ca2+ and covalently bound haem. EPR spectra of fully oxidized apo-QH-EDH and holo-QH-EDH showed g values typical for low-spin haem c proteins. In partially oxidized holo-QH-EDH an organic radical signal attributed to the semiquinone form of PQQ was observed. Binding of PQQ leads to conformational changes, as reflected by changes of spectral and chromatographic properties. Reconstitution of apoenzyme with PQQ analogues resulted in a decreased activity and enantioselectivity for the oxidation of chiral alcohols. Compared with PQQ, analogues with a large substituent had a lower affinity for the apoenzyme. Results with other analogues indicated that possession of the o-quinonelo-quinol moiety is not essential for binding but it is for activity.Keywords. Quinoprotein ; pyrroloquinoline quinone ; heme c ; alcohol dehydrogenase ; Comarnonas testosteroni. Quinohaemoprotein ethanol dehydrogenase (QH-EDH) fromCornamonas testosteroni catalyses the NAD-independent oxidation of a broad range of primary alcohols to the corresponding aldehydes and the (subsequent) oxidation of aldehydes to carboxylic acids. The soluble enzyme can be routinely isolated as the inactive, pyrroloquinoline-quinone (PQQ)-free, haem-c-containing apoenzyme from ethanol-grown cells cultivated at ambient temperatures. In the absence of PQQ in the medium, growth on alcohol still occurs and is most probably catalyzed via a NAD-dependent alcohol dehydrogenase [ 2 ] . Nevertheless it should be stressed that under this condition the QH-EDH apoenzyme is still produced [I]. Active holoenzyme is obtained by addition of equimolar amounts of PQQ (the structure of this cofactor is depicted in Fig. 7) in the presence of Ca2+. Alternatively, holoenzyme can be isolated directly from cells grown in the presence of PQQ. Small-scale isolation and preliminary characterization of apo-QH-EDH and holo-QH-EDH have been Enzyme. Quinohaemoprotein ethanol dehydrogenase (EC 1. I .99.-).described [I]. In the meantime, it was found that medium-scale and large-scale cultivation of C. testosteroni at different conditions of pH, tem...

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Purification and properties of methanol dehydrogenase fromMethylosinus sp. WI 14

Große

Voigt

Wendlandt

et al. 1998

J. Basic Microbiol.

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Similarly to the recently described methanol dehydrogenase (MDH) from Methylocystis sp. GB 25 (Grosse et al. 1997) MDH from Methylosinus sp. WI 14 is able to catalyse the oxi‐dation of methanol to formate directly. The enzyme was purified about 9‐fold to electrophoretic homogeneity and is localised in the soluble fraction. The relative molecular mass of the native enzyme has been determined to be 140 kDa. It is composed of two identical subunits of relative molecular mass 70 kDa. The amino terminal sequence shows a strong similarity (a match of 80% over the first 20 amino acids) to the MDH from Methylocystis sp. GB 25. PQQ could be detected as the prosthetic group of MDH in the purified enzyme fraction by using the apoenzyme of a membrane‐bound glucose dehydrogenase from Pseudomonas aeruginosa. A PQQ ratio of 1.3 per mole MDH was estimated. The purified enzyme has an optimum activity at pH 9.0 and at 57 °C. MDH from Methylosinus sp. WI 14 oxidises only primary alcohols up to octanol and several aldehydes. The estimated Km‐values vary between 0.18 mM for the sorbic alcohol and 6.3 mM for butanol and show no dependence upon the chain length.

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[41] Isolation, preparation, and assay of pyrroloquinoline quinone

Cited by 47 publications

References 39 publications

Quinoproteins: enzymes containing the quinonoid cofactor pyrroloquinoline quinone, topaquinone or tryptophan‐tryptophan quinone

Quinoproteins: enzymes containing the quinonoid cofactor pyrroloquinoline quinone, topaquinone or tryptophan‐tryptophan quinone

Quinohaemoprotein Ethanol Dehydrogenase from Comamonas testosteroni

Purification and properties of methanol dehydrogenase fromMethylosinus sp. WI 14

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