Enzymology of Quinoproteins

Duine, Johannis A.; Frank, J.; Jongejan, Jaap A.

doi:10.1002/9780470123058.ch4

Cited by 51 publications

(11 citation statements)

References 73 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…cm −1 (Supplementary Fig. S1) 5,32 . Metal content determined by inductively coupled plasma mass spectrometry (ICP-MS) showed that XoxF1-La contained La 3+ in 1:1 molar ratio of metal to protomer.…”

Section: Resultsmentioning

confidence: 99%

Contrasting in vitro and in vivo methanol oxidation activities of lanthanide-dependent alcohol dehydrogenases XoxF1 and ExaF from Methylobacterium extorquens AM1

Good

Moore

Suriano

et al. 2019

Sci Rep

View full text Add to dashboard Cite

Lanthanide (Ln) elements are utilized as cofactors for catalysis by XoxF-type methanol dehydrogenases (MDHs). A primary assumption is that XoxF enzymes produce formate from methanol oxidation, which could impact organisms that require formaldehyde for assimilation. We report genetic and phenotypic evidence showing that XoxF1 (MexAM1_1740) from Methylobacterium extorquens AM1 produces formaldehyde, and not formate, during growth with methanol. Enzyme purified with lanthanum or neodymium oxidizes formaldehyde. However, formaldehyde oxidation via 2,6-dichlorophenolindophenol (DCpIp) reduction is not detected in cell-free extracts from wild-type strain methanol-and lanthanum-grown cultures. Formaldehyde activating enzyme (Fae) is required for Ln methylotrophic growth, demonstrating that XoxF1-mediated production of formaldehyde is essential. Addition of exogenous lanthanum increases growth rate with methanol by 9-12% but does not correlate with changes to methanol consumption or formaldehyde accumulation. transcriptomics analysis of lanthanum methanol growth shows upregulation of xox1 and downregulation of mxa genes, consistent with the Ln-switch, no differential expression of formaldehyde conversion genes, downregulation of pyrroloquinoline quinone (pQQ) biosynthesis genes, and upregulation of fdh4 formate dehydrogenase (FDH) genes. Additionally, the Ln-dependent ethanol dehydrogenase exaF reduces methanol sensitivity in the fae mutant strain when lanthanides are present, providing evidence for the capacity of an auxiliary role for exaF during Ln-dependent methylotrophy. A direct link between the Ln elements and microbial metabolism has been firmly established with the discovery of PQQ-dependent alcohol dehydrogenases (ADHs), from methylotrophic bacteria, that contain a Ln atom in the active site 1-5. Thus far, Ln-PQQ ADHs can be grouped by their phylogeny and primary substrate as either XoxF-MDHs or ExaF-type ethanol dehydrogenases (EtDHs). MxaFI MDH has been considered the canonical primary catalyst for methanol oxidation in Gram-negative methylotrophs 6,7. The heterotetramer MxaFI contains PQQ that coordinates the calcium (Ca) ion 8-10. The discovery that Ln is incorporated into the active site of XoxF MDH in place of Ca, allowing catalytic function, has prompted the reexamination of methanol oxidation in methylotrophic bacteria 3,5,11-18. To date, only a few XoxF MDHs have been kinetically characterized 1,3,4,19,20. Phylogenetic analyses show there are at least five distinct families of XoxF MDHs 11,21 , and while it has been suggested that all XoxF MDHs may exhibit similar kinetic properties, reported data for these enzymes are currently inadequate to support such a broad characterization. In fact, recent studies have begun to identify differences in kinetic properties, cofactor usage, and pH optima of phylogenetically distinct XoxF enzymes 20,22,23. Lack of genes encoding the

show abstract

Section: Resultsmentioning

confidence: 99%

Contrasting in vitro and in vivo methanol oxidation activities of lanthanide-dependent alcohol dehydrogenases XoxF1 and ExaF from Methylobacterium extorquens AM1

Good

Moore

Suriano

et al. 2019

Sci Rep

View full text Add to dashboard Cite

show abstract

“…The absorption spectrum of the purified enzyme was recorded in a cuvette with a 1-cm path length at room temperature on a Cary 50 spectrophotometer (Agilent, Santa Clara, CA). The concentration and content of the PQQ prosthetic group were calculated on the basis of a molar absorption coefficient of 9,620 M Ϫ1 cm Ϫ1 at 342 nm for PQQ (55). Inductively coupled plasma mass spectrometry (ICP-MS) was performed to analyze and quantify the metal content of purified protein with the setup and calibration mixture described by Pol et al (43).…”

Section: Methodsmentioning

confidence: 99%

XoxF-Type Methanol Dehydrogenase from the Anaerobic Methanotroph “Candidatus Methylomirabilis oxyfera”

Wessels

Pol

et al. 2015

Appl Environ Microbiol

View full text Add to dashboard Cite

b "Candidatus Methylomirabilis oxyfera" is a newly discovered anaerobic methanotroph that, surprisingly, oxidizes methane through an aerobic methane oxidation pathway. The second step in this aerobic pathway is the oxidation of methanol. In Gramnegative bacteria, the reaction is catalyzed by pyrroloquinoline quinone (PQQ)-dependent methanol dehydrogenase (MDH). The genome of "Ca. Methylomirabilis oxyfera" putatively encodes three different MDHs that are localized in one large gene cluster: one so-called MxaFI-type MDH and two XoxF-type MDHs (XoxF1 and XoxF2). MxaFI MDHs represent the canonical enzymes, which are composed of two PQQ-containing large (␣) subunits (MxaF) and two small (␤) subunits (MxaI). XoxF MDHs are novel, ecologically widespread, but poorly investigated types of MDHs that can be phylogenetically divided into at least five different clades. The XoxF MDHs described thus far are homodimeric proteins containing a large subunit only. Here, we purified a heterotetrameric MDH from "Ca. Methylomirabilis oxyfera" that consisted of two XoxF and two MxaI subunits. The enzyme was localized in the periplasm of "Ca. Methylomirabilis oxyfera" cells and catalyzed methanol oxidation with appreciable specific activity and affinity (V max of 10 mol min ؊1 mg ؊1 protein, K m of 17 M). PQQ was present as the prosthetic group, which has to be taken up from the environment since the known gene inventory required for the synthesis of this cofactor is lacking. The MDH from "Ca. Methylomirabilis oxyfera" is the first representative of type 1 XoxF proteins to be described.

show abstract

“…Logarithmically growing cells (1x10 4 ) were plated in each well of 96-well plates containing various concentrations of the test compounds and then cultured for 72 h according to the method of Mosmann (24) as described previously (25). The culture was incubated for 4 h in the presence of 0.5 mg/ml MTT, and then the absorbance at 570 nm (using a reference wavelength of 655 nm) was measured.…”

Section: Methodsmentioning

confidence: 99%

“…PQQ is synthesized by a number of microorganisms and is essential for their growth (2)(3)(4). Several reports have suggested physiological and pharmacological effects of PQQ such as protection from liver damage by ethanol in rats (5), oxidation of the N-methyl-D-aspartate receptor redox site in rat cortical neurons (6), protection from reoxygenation injury in isolated rabbit heart (7), increase in levels of nerve growth factor in mouse astroglial cells (8), inhibition of melanogenesis in murine B16-F10 melanoma (9), and enhancement of rat sciatic nerve regeneration (10).…”

Section: Introductionmentioning

confidence: 99%

Activation of Ras signaling pathways by pyrroloquinoline quinone in NIH3T3 mouse fibroblasts

Kumazawa¹,

Hiwasa²,

Takao³

et al. 2007

Int J Mol Med

View full text Add to dashboard Cite

Abstract. Pyrroloquinoline quinone (PQQ) has been implicated in certain physiological activities in mammals such as functioning as a potent growth factor in mice, and promoting DNA synthesis in human fibroblasts. These are clearly important physiological functions, however, the molecular mechanisms involved in PQQ activity are not yet fully understood. In order to address this, in this study we analyzed the effects of PQQ on the proliferation of NIH3T3 mouse fibroblasts and on their intracellular signal transduction mechanism. When activated c-Ha-ras-transformed NIH3T3 cells were treated with PQQ in the presence of 0.5% calf serum in DMEM, the cells showed significantly increased viability. After PQQ addition, flow cytometric analysis revealed a decrease in the population of cells in the G 0 /G 1 phase and a concomitant increase in cells in the S and G 2 /M phases. Although treatment with SNAP, an NO donor, reduced cell viability, this effect was abolished by the addition of PQQ. Activation of ERK and PKC-ε was detected immediately after the addition of PQQ, and subsequent increases in the phosphorylation of Rb and c-Jun were observed. On the other hand, protein expression levels of growth-inhibitory molecules such as IκB and p27 decreased after PQQ treatment. These results suggest that PQQ stimulates cell proliferation through NO-sensitive Rasmediated signaling pathways.

show abstract

Enzymology of Quinoproteins

Cited by 51 publications

References 73 publications

Contrasting in vitro and in vivo methanol oxidation activities of lanthanide-dependent alcohol dehydrogenases XoxF1 and ExaF from Methylobacterium extorquens AM1

Contrasting in vitro and in vivo methanol oxidation activities of lanthanide-dependent alcohol dehydrogenases XoxF1 and ExaF from Methylobacterium extorquens AM1

XoxF-Type Methanol Dehydrogenase from the Anaerobic Methanotroph “Candidatus Methylomirabilis oxyfera”

Activation of Ras signaling pathways by pyrroloquinoline quinone in NIH3T3 mouse fibroblasts

Contact Info

Product

Resources

About