*  Pyrroloquinoline quinone inhibits the fibrillation of amyloid proteins
Several types of oxidoreductases found in Gram-negative bacteria were found to possess PQQ as their cofactor (Fig. 1).6 Due to ... with 300 µM PQQ lower compared to those observed in the absence of PQQ. Therefore, it indicated that PQQ decreased the ... Moreover, PQQ-conjugated α-Syn is also able to prevent α-Syn amyloid fibril formation.11 The fact that PQQ shows anti-fibril- ... Here we showed PQQ decreased the fibril formation of Aβ1-42. The ThT observation suggested the presence of PQQ resulted in the ...
*  Publications • AG Bittl • Department of Physics
Characterisation of the PQQ-cofactor radical in quinoprotein ethanol dehydrogenase of Pseudomonas aeruginosa by electron ... Hindered Rotation of a Cofactor Methyl Group as a Probe for Protein-Cofactor Interaction.. J. Am. Chem. Soc., 132(26):8935-8944 ... Structural insights into the incorporation of the Mo cofactor into sulfite oxidase from site directed spin labeling.. Angew. ... The g-Tensor of the Neutral Flavin Radical Cofactor of DNA Photolyase Revealed by 360-GHz Electron Paramagnetic Resonance ...
*  Patent US20090084687 - Systems and methods of discriminating control solution from a physiological ... - Google Patents
... based on the PQQ co-factor and ferricyanide. In another embodiment, the enzyme GDH based on the PQQ co-factor may be replaced ... Examples of suitable enzymes include glucose oxidase, glucose dehydrogenase (GDH) based on pyrroloquinoline quinone (PQQ) co- ... factor, GDH based on nicotinamide adenine dinucleotide co-factor, and FAD-based GDH [E.C.]. One exemplary reagent ... with the enzyme GDH based on the FAD co-factor. When blood or control solution is dosed into a sample reaction chamber 61, ...
*  aldehyde dehydrogenase (quinone)(EC - Creative Enzymes
The enzymes contains a PQQ cofactor and multiple hemes th ... The enzymes contains a PQQ cofactor and multiple hemes that ...
*  Alcohol dehydrogenase (cytochrome c) - Wikipedia
Kay, C.W.; Mennenga, B.; Gorisch, H.; Bittl, R. (2004). "Characterisation of the PQQ cofactor radical in quinoprotein ethanol ... 2 H+ A periplasmic PQQ-containing quinoprotein is present in Pseudomonas and Rhodopseudomonas. Rupp, M.; Gorisch, H. (1988). " ...
*  Choline dehydrogenase - Wikipedia
It employs one cofactor, PQQ. Minoru Ameyama; Emiko Shinagawa; Kazunobu Matsushita; Koichi Takimoto; Koji Nakashima; Osao ...
*  Polyvinyl-alcohol dehydrogenase (acceptor) - Wikipedia
It employs one cofactor, PQQ. Shimao M, Ninomiya K, Kuno O, Kato N, Sakazawa C (1986). "Existence of a novel enzyme, ...
*  Aldehyde dehydrogenase (pyrroloquinoline-quinone) - Wikipedia
It employs one cofactor, PQQ. Ameyama M; Adachi O (1982). "Aldehyde dehydrogenase from acetic acid bacteria, membrane-bound". ...
*  Alkan-1-ol dehydrogenase (acceptor) - Wikipedia
It employs one cofactor, PQQ. Kawai F, Kimura T, Tani Y, Yamada H, Ueno T & Fukami H (1983). "Identification of reaction- ...
*  Alcohol dehydrogenase (acceptor) - Wikipedia
It employs one cofactor, PQQ. As of late 2007, 11 structures have been solved for this class of enzymes, with PDB accession ...
*  Glycerol dehydrogenase (acceptor) - Wikipedia
It employs one cofactor, PQQ. Ameyama M, Shinagawa E, Matsushita K, Adachi O (1985). "Solubilization, purification and ...
*  Quinoprotein glucose dehydrogenase - Wikipedia
It employs one cofactor, PQQ. Ameyama, Minoru; Nonobe Masatsugu; Hayashi Masaharu; Shinagawa Emiko; Matsushita Kazunobu; Adachi ... Dewanti AR, Duine JA (1998). "Reconstitution of membrane-integrated quinoprotein glucose dehydrogenase apoenzyme with PQQ and ... Other names in common use include D-glucose:(pyrroloquinoline-quinone) 1-oxidoreductase, glucose dehydrogenase (PQQ-dependent ... a covalent cofactor-inhibitor complex". Proc. Natl. Acad. Sci. U.S.A. 96 (21): 11787-91. doi:10.1073/pnas.96.21.11787. PMC ...
*  List of MeSH codes (D03) - Wikipedia
... pqq cofactor MeSH D03.438.810.842 --- quinpirole MeSH D03.438.810.850 --- quipazine MeSH D03.438.810.900 --- saquinavir MeSH ...
*  Pyrroloquinoline quinone - Wikipedia
... might also use PQQ as a cofactor, suggesting a possibility that PQQ is a vitamin in mammals. PMID 12712191. ... Pyrroloquinoline quinone (PQQ) is redox cofactor. It is found in soil and foods such as kiwifruit, as well as human breast milk ... PQQ stimulates growth in bacteria. It was discovered by J.G. Hauge as the third redox cofactor after nicotinamide and flavin in ... Felton LM, Anthony C (2005). "Biochemistry: role of PQQ as a mammalian enzyme cofactor?". Nature. 433 (7025): E10; discussion ...
*  CN102918388A - Electrochemical analyte measurement method and system - Google Patents
... the PQQ) co-factor, and glucose dehydrogenase having flavin adenine dinucleotide (FAD) cofactor of the glucose dehydrogenase ... 0055] 适用于试剂层的示例性酶包括葡萄糖氧化酶、具有吡咯喹啉醌(PQQ)辅因子的葡萄糖脱
*  WO2012035297A1 - Analyte measurement method and system with hematocrit compensation - Google Patents
PQQ) co-factor and glucose dehydrogenase with a flavin adenine dinucleotide (FAD) co-factor. An exemplary mediator PATENT ...
*  Frontiers | Isolation and characterization of a β-propeller gene containing phosphobacterium Bacillus subtilis strain KPS-11...
... pqqABCDEF) is responsible for encoding proteins (polypeptides), precursors for PQQ synthesis. PQQ is considered as co-factor in ... A gene pqq encods pyrroloquinoline quinine (PQQ) which is a co-factor of holenzyme glucose dehydrogenase (GDH). GDH is ... Universal primers pqqF/pqqR2 (Perez et al., 2007) were used for the amplification of the pqqE gene in bacterial strain KPS-11 ... In most of the bacteria containing PQQ there are present six or seven genes (pqqABCDEF/G) in an operon. PQQ biosynthesis ...
*  Pyridoxine 5-dehydrogenase - Wikipedia
It has 2 cofactors: FAD, and PQQ. Sundaram TK, Snell EE (1969). "The bacterial oxidation of vitamin B6. V. The enzymatic ...
*  "Study of Soluble Glucose Dehydrogenase (sGDH) based upon Kinetic Studi" by James Ewing, Carolnn Yong et al.
Hydrolysis of the oxidation product yields an isomeric analog of PQQ. These isomers differ in the positioning of the nitrogen ... cofactors for its full enzymatic activity. sGDH catalyses the oxidation of glucose and other aldose sugars. The mechanistic ... Here, three isomeric analogs of PQQ are systematically selected and synthesized from methoxynitroaniline derivatives. Each ... which was further oxidized into the triester of a PQQ analog. ... and will serve to define the structural significance of PQQ in ...
*  Pyrroloquinoline quinone stimulates epithelial cell proliferation by activating epidermal growth factor receptor through redox...
Pyrroloquinoline quinone (PQQ), a redox cofactor for bacterial dehydrogenases, has been implicated to be an important nutrient ... Our results provide novel insight into the mechanisms by which PQQ may function as a growth factor to contribute to mammalian ... PQQ inhibited protein tyrosine phosphatase 1B (PTP1B), which negatively regulates the EGFR signaling by tyrosine ... Our data suggest that PQQ may stimulate epithelial cell proliferation by activating EGFR by oxidation and subsequent ...
*  Amine oxidase (copper-containing) - Wikipedia
It has 2 cofactors: copper, and PQQ. The copper amine oxidase 3-dimensional structure was determined through X-ray ... each monomer containing a copper ion and a covalently bound redox cofactor, topaquinone (TPQ). TPQ is formed by post- ... which requires one copper ion per subunit and topaquinone as cofactor: RCH2NH2 + H2O + O2 ⇌ {\displaystyle \rightleftharpoons ...
*  Patent US20070275430 - Determining The Concentration Of Analytes In Sample By Direct Mediation Of ... - Google Patents
... of blood can be determined by contacting a blood sample with a test strip containing a glucose dehydrogenase dependent on PQQ ( ... b) as a co-factor for GDH, pyrrolo-quinoline quinone (PQQ) or a PQQ derivative or isomer, said GDH and co-factor being capable ... b) as a co-factor for GDH, pyrrolo-quinoline quinone (PQQ) or a PQQ derivative or isomer, said GDH and co-factor being capable ... 2) as a co-factor for GDH, pyrrolo-quinoline quinone (PQQ) or a PQQ derivative or isomer, said GDH and co-factor being capable ...
*  ProMito PQQ™ by ProHealth (Mitochondrial Support) - ProHealth.com
ProMito PQQ is a unique blend that combines PQQ (a nutrient that stimulates mitochondrial growth and ATP production) and Alpha ... What is ProMito PQQ?. Pyrrolloquinoline (PQQ) is an enzyme cofactor functionally related to the B vitamin family. First ... PQQ Studies. In humans, PQQ has been scientifically studied for its neuroprotective properties.* In one double blind placebo ... ProMito PQQ™ is a unique blend that combines PQQ (a nutrient that stimulates mitochondrial growth and ATP production) and Alpha ...
*  Christopher Kay
Several quinoproteins contain the noncovalently bound quinoid cofactor pyrroloquinoline quinone (PQQ), the role of which as a ... The first of these papers describes the characterisation of the PQQ radical in Quinoprotein Ethanol Dehydrogenase, by advanced ... clusters and organic cofactors, and nitroxide spin-labels engineered into proteins by, for example, ENDOR (electron-nuclear ... a covalent adduct between the flavin cofactor and nearby cysteine residue. ...
*  Thorne Research Perfusia-SR, 120 Capsules in Canada only $47.35 | Free Shipping over $49
Perfusia Plus improves on the original Perfusia-SR by combining sustained-release L-arginine with nutritional cofactors ...

(1/143) Characterization of the membrane quinoprotein glucose dehydrogenase from Escherichia coli and characterization of a site-directed mutant in which histidine-262 has been changed to tyrosine.

The requirements for substrate binding in the quinoprotein glucose dehydrogenase (GDH) in the membranes of Escherichia coli are described, together with the changes in activity in a site-directed mutant in which His262 has been altered to a tyrosine residue (H262Y-GDH). The differences in catalytic efficiency between substrates are mainly related to differences in their affinity for the enzyme. Remarkably, it appears that, if a hexose is able to bind in the active site, then it is also oxidized, whereas some pentoses are able to bind (and act as competitive inhibitors), but are not substrates. The activation energies for the oxidation of hexoses and pentoses are almost identical. In a previously published model of the enzyme, His262 is at the entrance to the active site and appears to be important in holding the prosthetic group pyrroloquinoline quinone (PQQ) in place, and it has been suggested that it might play a role in electron transfer from the reduced PQQ to the ubiquinone in the membrane. The H262Y-GDH has a greatly diminished catalytic efficiency for all substrates, which is mainly due to a marked decrease in their affinities for the enzyme, but the rate of electron transfer to oxygen is unaffected. During the processing of the PQQ into the apoenzyme to give active enzyme, its affinity is markedly dependent on the pH, four groups with pK values between pH7 and pH8 being involved. Identical results were obtained with H262Y-GDH, showing that His262 it is not directly involved in this process.  (+info)

(2/143) Functions of amino acid residues in the active site of Escherichia coli pyrroloquinoline quinone-containing quinoprotein glucose dehydrogenase.

Several mutants of quinoprotein glucose dehydrogenase (GDH) in Escherichia coli, located around its cofactor pyrroloquinoline quinone (PQQ), were constructed by site-specific mutagenesis and characterized by enzymatic and kinetic analyses. Of these, critical mutants were further characterized after purification or by different amino acid substitutions. H262A mutant showed reduced affinities both for glucose and PQQ without significant effect on glucose oxidase activity, indicating that His-262 occurs very close to PQQ and glucose, but is not the electron acceptor from PQQH(2). W404A and W404F showed pronounced reductions of affinity for PQQ, and the latter rather than the former had equivalent glucose oxidase activity to the wild type, suggesting that Trp-404 may be a support for PQQ and important for the positioning of PQQ. D466N, D466E, and K493A showed very low glucose oxidase activities without influence on the affinity for PQQ. Judging from the enzyme activities of D466E and K493A, as well as their absorption spectra of PQQ during glucose oxidation, we conclude that Asp-466 initiates glucose oxidation reaction by abstraction of a proton from glucose and Lys-493 is involved in electron transfer from PQQH(2).  (+info)

(3/143) Novel role for the NMDA receptor redox modulatory site in the pathophysiology of seizures.

Redox-active compounds modulate NMDA receptors (NMDARs) such that reduction of NMDAR redox sites increases, and oxidation decreases, NMDAR-mediated activity. Because NMDARs contribute to the pathophysiology of seizures, redox-active compounds also may modulate seizure activity. We report that the oxidant 5, 5'-dithio-bis(2-nitrobenzoic acid) (DTNB) and the redox cofactor pyrroloquinoline quinone (PQQ) suppressed low Mg(2+)-induced hippocampal epileptiform activity in vitro. Additionally, in slices exposed to 4-7 microM bicuculline, DTNB and PQQ reversed the potentiation of evoked epileptiform responses by the reductants dithiothreitol and Tris(2-carboxyethyl)phosphine (TCEP). NMDA-evoked whole-cell currents in CA1 neurons in slices were increased by TCEP and subsequently decreased by DTNB or PQQ at the same concentrations that modulated epileptiform activity. However, DTNB and PQQ had little effect on baseline NMDA-evoked currents in control medium, and PQQ did not alter NMDAR-dependent long-term potentiation. In contrast, in slices returned to control medium after low Mg(2+)-induced ictal activity, DTNB significantly inhibited NMDAR-mediated currents, indicating endogenous reduction of NMDAR redox sites under this epileptogenic condition. These data suggested that PQQ and DTNB suppressed spontaneous ictal activity by reversing pathological NMDAR redox potentiation without inhibiting physiological NMDAR function. In vivo, PQQ decreased the duration of chemoconvulsant-induced seizures in rat pups with no effect on baseline behavior. Our results reveal endogenous potentiation of NMDAR function via mass reduction of redox sites as a novel mechanism that may enhance epileptogenesis and facilitate the transition to status epilepticus. The results further suggest that redox-active compounds may have therapeutic use by reversing NMDAR-mediated pathophysiology without blocking physiological NMDAR function.  (+info)

(4/143) Physiological importance of quinoenzymes and the O-quinone family of cofactors.

O-quinone cofactors derived from tyrosine and tryptophan are involved in novel biological reactions that range from oxidative deaminations to free-radical redox reactions. The formation of each of these cofactors appears to involve post-translational modifications of either tyrosine or tryptophan residues. The modifications result in cofactors, such as topaquinone (TPQ), tryptophan tryptophylquinone (TTQ), lysine tyrosylquinone (LTQ) or the copper-complexed cysteinyl-tyrosyl radical from metal-catalyzed reactions. Pyrroloquinoline quinone (PQQ) appears to be formed from the annulation of peptidyl glutamic acid and tyrosine residues stemming from their modification as components of a precursor peptide substrate. PQQ, a primary focus of this review, has invoked considerable interest because of its presence in foods, antioxidant properties and role as a growth-promoting factor. Although no enzymes in animals have been identified that exclusively utilize PQQ, oral supplementation of PQQ in nanomolar amounts increases the responsiveness of B- and T-cells to mitogens and improves neurologic function and reproductive outcome in rodents. Regarding TPQ and LTQ, a case may be made that the formation of TPQ and LTQ is also influenced by nutritional status, specifically dietary copper. For at least one of the amine oxidases, lysyl oxidase, enzymatic activity correlates directly with copper intake. TPQ and LTQ are generated following the incorporation of copper by a process that involves the two-step oxidation of a specified tyrosyl residue to first peptidyl dopa and then peptidyl topaquinone to generate active enzymes, generally classed as "quinoenzymes." Limited attention is also paid to TTQ and the copper-complexed cysteinyl-tyrosyl radical, cofactors important to fungal and bacterial redox processes.  (+info)

(5/143) Structural requirements of pyrroloquinoline quinone dependent enzymatic reactions.

On the basis of crystal structures of the pyrroloquinoline quinone (PQQ) dependent enzymes methanol dehydrogenase (MDH) and soluble glucose dehydrogenase (s-GDH), different catalytic mechanisms have been proposed. However, several lines of biochemical and kinetic evidence are strikingly similar for both enzymes. To resolve this discrepancy, we have compared the structures of these enzymes in complex with their natural substrates in an attempt to bring them in line with a single reaction mechanism. In both proteins, PQQ is located in the center of the molecule near the axis of pseudo-symmetry. In spite of the absence of significant sequence homology, the overall binding of PQQ in the respective active sites is similar. Hydrogen bonding interactions are made with polar protein side chains in the plane of the cofactor, whereas hydrophobic stacking interactions are important below and above PQQ. One Arg side chain and one calcium ion are ligated to the ortho-quinone group of PQQ in an identical fashion in either active site, in agreement with their proposed catalytic function of polarizing the PQQ C5-O5 bond. The substrates are bound in a similar position above PQQ and within hydrogen bond distance of the putative general bases Asp297 (MDH) and His144 (s-GDH). On the basis of these similarities, we propose that MDH and s-GDH react with their substrates through an identical mechanism, comprising general base-catalyzed hydride transfer from the substrate to PQQ and subsequent tautomerization of the PQQ intermediate to reduced PQQ.  (+info)

(6/143) Synthesis of [(14)C]pyrroloquinoline quinone (PQQ) in E. coli using genes for PQQ synthesis from K. pneumoniae.

Radiochemical forms of pyrroloquinoline quinone (PQQ) are of utility in studies to determine the metabolic role and fate of PQQ in biological systems. Accordingly, we have synthesized [(14)C]PQQ using a tyrosine auxotrophic strain of Escherichia coli (AT2471). A construct containing the six genes required for PQQ synthesis from Klebsiella pneumoniae was used to transform the auxotrophic strain of E. coli. E. coli were then grown in minimal M9 medium containing 3.7x10(9) Bq/mmol [(14)C]tyrosine. At confluence, the medium was collected and applied to a DEAE A-25 anionic exchange column; [(14)C]PQQ was eluted using a KCl gradient (0-2 M in 0.1 M potassium phosphate buffer, pH 7.0). Radioactivity co-eluting as PQQ was next pooled, acidified and passed through a C-18 column; [(14)C]PQQ was eluted with a phosphate buffer (0.1 M, pH 7.0). Reverse phase HPLC (C-18) using either the ion-pairing agent trifluoroacetic acid (0. 1%) and an acetonitrile gradient or phosphoric acid and a methanol gradient were used to isolate [(14)C]PQQ. Fractions were collected and analyzed by liquid scintillation counting. (14)C-labelled compounds isolated from the medium eluted corresponding to the elution of various tyrosine-derived products or PQQ. The radioactive compound corresponding to PQQ was also reacted with acetone to form 5-acetonyl-PQQ, which co-eluted with a 5-acetonyl-PQQ standard, as a validation of [(14)C]PQQ synthesis. The specific activity of synthesized [(14)C]PQQ was 3.7x10(9) Bq/mmol [(14)C]PQQ, equal to that of [U-(14)C]tyrosine initially added to the medium.  (+info)

(7/143) Ca(2+) stabilizes the semiquinone radical of pyrroloquinoline quinone.

Spectroelectrochemical studies were performed on the interaction between Ca(2+) and pyrroloquinoline quinone (PQQ) in soluble glucose dehydrogenase (sGDH) and in the free state by applying a mediated continuous-flow column electrolytic spectroelectrochemical technique. The enzyme forms used were holo-sGDH (the holo-form of sGDH from Acinetobacter calcoaceticus) and an incompletely reconstituted form of this, holo-X, in which the PQQ-activating Ca(2+) is lacking. The spectroelectrochemical and ESR data clearly demonstrated the generation of the semiquinone radical of PQQ in holo-sGDH and in the free state in the presence of Ca(2+). In contrast, in the absence of Ca(2+) no semiquinone was observed, either for PQQ in the free state (at pH 7.0) or in the enzyme (holo-X). Incorporation of Ca(2+) into the active site of holo-X, yielding holo-sGDH, caused not only stabilization of the semiquinone form of PQQ but also a negative shift (of 26.5 mV) of the two-electron redox potential, indicating that the effect of Ca(2+) is stronger on the oxidized than on the reduced PQQ. Combining these data with the observations on the kinetic and chemical mechanisms, it was concluded that the strong stimulating effect of Ca(2+) on the activity of sGDH can be attributed to facilitation of certain kinetic steps, and not to improvement of the thermodynamics of substrate oxidation. The consequences of this conclusion are discussed for the oxidative as well as for the reductive part of the reaction of sGDH.  (+info)

(8/143) Membrane-associated quinoprotein formaldehyde dehydrogenase from Methylococcus capsulatus Bath.

A membrane-associated, dye-linked formaldehyde dehydrogenase (DL-FalDH) was isolated from the obligate methylotroph Methylococcus capsulatus Bath. The enzyme was the major formaldehyde-oxidizing enzyme in cells cultured in high (above 1 micromol of Cu per mg of cell protein) copper medium and expressing the membrane-associated methane monooxygenase. Soluble NAD(P)(+)-linked formaldehyde oxidation was the major activity in cells cultured in low-copper medium and expressing the soluble methane monooxygenase (Tate and Dalton, Microbiology 145:159-167, 1999; Vorholt et al., J. Bacteriol. 180:5351-5356, 1998). The membrane-associated enzyme is a homotetramer with a subunit molecular mass of 49,500 Da. UV-visible absorption, electron paramagnetic resonance, and electrospray mass spectrometry suggest the redox cofactor of the DL-FalDH is pyrroloquinoline quinone (PQQ), with a PQQ-to-subunit stochiometry of approximately 1:1. The enzyme was specific for formaldehyde, oxidizing formaldehyde to formate, and utilized the cytochrome b(559/569) complex as the physiological electron acceptor.  (+info)

  • PqqA
  • The need for two modifications to MftA by MftC might explain the high degree of amino acid conservation in the last eight residues of MftA, as compared to the level of conservation seen for PqqA, precursor of PQQ. (wikipedia.org)
  • vitamin
  • The scientific journal Nature published the 2003 paper by Kasahara and Kato that essentially stated that PQQ was a new vitamin and in 2005, an article by Anthony and Fenton that stated that the 2003 Kasahara and Kato paper drew incorrect and unsubstantiated conclusions. (wikipedia.org)
  • 7 , 8 Recently, it has been proposed that PQQ be classified as a new B vitamin. (pubmedcentralcanada.ca)
  • Pyrrolloquinoline (PQQ) is an enzyme cofactor functionally related to the B vitamin family. (prohealth.com)
  • tyrosine
  • The present study revealed that PQQ induces the activation (tyrosine autophosphorylation) of epidermal growth factor receptor (EGFR) and its downstream signaling in a ligand-independent manner, leading to increased cellular proliferation in an epithelial cell line A431. (sigmaaldrich.com)
  • aldehyde
  • This enzyme catalyses the following chemical reaction a primary alcohol + 2 ferricytochrome c ⇌ {\displaystyle \rightleftharpoons } an aldehyde + 2 ferrocytochrome c + 2 H+ A periplasmic PQQ-containing quinoprotein is present in Pseudomonas and Rhodopseudomonas. (wikipedia.org)
  • copper
  • They catalyse the oxidation of primary amines to aldehydes, with the subsequent release of ammonia and hydrogen peroxide, which requires one copper ion per subunit and topaquinone as cofactor: RCH2NH2 + H2O + O2 ⇌ {\displaystyle \rightleftharpoons } RCHO + NH3 + H2O2 The 3 substrates of this enzyme are primary amines (RCH2NH2), H2O, and O2, whereas its 3 products are RCHO, NH3, and H2O2. (wikipedia.org)
  • It has 2 cofactors: copper, and PQQ. (wikipedia.org)
  • Dopamine β-hydroxylase has 3 cofactors: copper, PQQ, and Fumarate. (medchemexpress.cn)
  • analog
  • Michael addition of an aminoindole derivative with dimethyl trans-2-ketoglutaconate was performed to form the pyridine ring, which was further oxidized into the triester of a PQQ analog. (oxy.edu)
  • Hydrolysis of the oxidation product yields an isomeric analog of PQQ. (oxy.edu)
  • nitrogen
  • These isomers differ in the positioning of the nitrogen atom on the ring system and will serve to define the structural significance of PQQ in terms of binding with a metal cation and reconstitution process with the apoprotein. (oxy.edu)
  • novel
  • Our results provide novel insight into the mechanisms by which PQQ may function as a growth factor to contribute to mammalian growth. (sigmaaldrich.com)
  • found
  • Adachi and colleagues discovered that PQQ was also found in Acetobacter. (wikipedia.org)
  • Several types of oxidoreductases found in Gram-negative bacteria were found to possess PQQ as their cofactor ( Fig. 1 ). (pubmedcentralcanada.ca)
  • In one double blind placebo controlled study in middle aged and elderly adults, supplementation with PQQ was found to support healthy cognitive function, including high end mental processing. (prohealth.com)
  • growth
  • Recent evidence indicates PQQ can support several signal transduction pathways that are important in maintaining mitochondrial homeostasis and oxidative function, as well as supporting healthy levels of nerve growth factor and receptor activity. (prohealth.com)
  • presence
  • The fibril formation of mouse prion protein in the presence of PQQ was dramatically prevented. (pubmedcentralcanada.ca)
  • Thus, we consider that the ThT fluorescence intensity means the relative amount of fibrils formed in the presence and absence of PQQ. (pubmedcentralcanada.ca)
  • In the presence of PQQ, fibril formation was prevented, as indicated by the reduced ThT fluorescence over the time course. (pubmedcentralcanada.ca)
  • activity
  • 11 The fact that PQQ shows anti-fibril-forming activity and that the common feature of these neurodegenerative diseases is amyloid fibril formation encouraged us to further investigate the effects of PQQ on the fibrillization of amyloid proteins, prion protein (PrP) and amyloid β (1-42) (Aβ 1-42 ). (pubmedcentralcanada.ca)
  • further
  • With further advanced pharmacological approaches, PQQ may become a leading anti-neurodegenerative compound in the treatment of neurodegenerative diseases. (pubmedcentralcanada.ca)
  • production
  • PQQ-inducible intracellular ROS production and EGFR activation were significantly suppressed by the pre-treatment with antioxidants. (sigmaaldrich.com)
  • structure
  • ESR/EPR can provide unique information on the identity and structure of stable and transient paramagnetic species such as defects, metals, clusters and organic cofactors, and nitroxide spin-labels engineered into proteins by, for example, ENDOR (electron-nuclear double resonance) and HYSCORE (hyperfine correlation spectroscopy). (london-nano.com)