Pyrroloquinoline quinone

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CASNo=72909-34-3
PubChem=1024
ChemSpiderID = 997
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MeSHName=PQQ+Cofactor
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Formula=C₁₄H₆N₂O₈
MolarMass=330.206 g/mol
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Pyrroloquinoline quinone (PQQ) was discovered by Houge as the third redox cofactor after nicotinamide and flavin in bacteria. [cite journal | author = Hauge JG | title = Glucose dehydrogenase of bacterium anitratum: an enzyme with a novel prosthetic group | journal = J Biol Chem | year = 1964 | volume = 239 | pages = 3630–9 PMID 14257587 ] Anthony and Zatman also found the unknown redox cofactor in alcohol dehydrogenase and named Metoxatin. [cite journal | author = Anthony C, Zatman LJ | title = The microbial oxidation of methanol. The prosthetic group of the alcohol dehydrogenase of Pseudomonas sp. M27: a new oxidoreductase prosthetic group | journal = Biochem J | year = 1967 | volume = 104 | issue = 3 | pages = 960–9 PMID 6049934 ] In 1979, Salisbury and colleagues [cite journal | author = Salisbury SA, Forrest HS, Cruse WB, Kennard O | title = A novel coenzyme from bacterial primary alcohol dehydrogenases | journal = Nature | year = 1979 | volume = 280 | issue = 5725 | pages = 843–4 | doi = 10.1038/280843a0 PMID 471057] as well as Duine and colleagues [cite journal | author = Westerling J, Frank J, Duine JA | title = The prosthetic group of methanol dehydrogenase from Hyphomicrobium X: electron spin resonance evidence for a quinone structure | journal = Biochem Biophys Res Commun | year = 1979 | volume = 87 | issue = 3 | pages = 719–24 | doi = 10.1016/0006-291X(79)92018-7 PMID 222269 ] extracted this prosthetic group from methanol dehydrogenase of methylotrophs and identified its molecular structure. Adachi and colleagues identified that PQQ was also found in "Acetobacter". [cite journal | author = Ameyama M, Matsushita K, Ohno Y, Shinagawa E, Adachi O | title = Existence of a novel prosthetic group, PQQ, in membrane-bound, electron transport chain-linked, primary dehydrogenases of oxidative bacteria | journal = FEBS Lett | year = 1981 | volume = 130 | issue = 2 | pages = 179–83 | doi = 10.1016/0014-5793(81)81114-3 PMID 6793395 ]

These enzymes containing PQQ are called quinoproteins. Glucose dehydrogenase, one of the quinoproteins, is used as a glucose sensor. Subsequently, PQQ was found to stimulate growth in bacteria. [cite journal | author = Ameyama M, Matsushita K, Shinagawa E, Hayashi M, Adachi O | title = Pyrroloquinoline quinone: excretion by methylotrophs and growth stimulation for microorganisms | journal = Biofactors | year = 1988 | volume = 1 | issue = 1 | pages = 51–3 PMID 2855583 ] In addition, antioxidant and neuro-protective effects were also found.

In 1989, Rucker and colleagues reported that mice deprived of PQQ showed various abnormalities, and it was suggested that PQQ might have an important nutritional role also in mammals. [cite journal | author = Killgore J, Smidt C, Duich L, Romero-Chapman N, Tinker D, Reiser K, Melko M, Hyde D, Rucker RB | title = Nutritional importance of pyrroloquinoline quinone | journal = Science | year = 1989 | volume = 245 | issue = 4920 | pages = 850–2 | doi = 10.1126/science.2549636 | pmid = 2549636 PMID 2549636] In 2003, it was reported that aminoadipate semialdehyde dehydrogenase (AASDH) might also use PQQ as a cofactor, suggesting a possibility that PQQ is a vitamin in mammals. [cite journal | author = Kasahara T, Kato T | title = Nutritional biochemistry: A new redox-cofactor vitamin for mammals | journal = Nature | year = 2003 | volume = 422 | issue = 6934 | pages = 832 | doi = 10.1038/422832a PMID 12712191] However, there is no direct evidence that AASDH requires PQQ as a cofactor in its enzymatic activity. Rucker and colleagues concluded that insufficient information is available so far to state that PQQ is a vitamin for mammals, although PQQ may be an important biological factor. [cite journal | author = Rucker R, Storms D, Sheets A, Tchaparian E, Fascetti A | title = Biochemistry: is pyrroloquinoline quinone a vitamin? | journal = Nature | year = 2005 | volume = 433 | issue = 7025 | pages = E10–1; discussion E11–2 | doi = 10.1038/nature03323 PMID 15689994] Interestingly, it was recently shown that PQQ may stimulate growth of plants (cucumbers and tomatoes) in hydroponic culture and may be the causative factor in plant growth stimulation by a strain of "Pseudomonas fluorescens" bacterium. [cite journal | author = Choi, O., Kim, J., Kim, J.-G., Jeong, Y., Moon, J. S., Park, C. S., Hwang, I.| title = PLANTS INTERACTING WITH OTHER ORGANISMS Pyrroloquinoline Quinone Is a Plant Growth Promotion Factor Produced by Pseudomonas fluorescens B16 | journal = Plant Physiology | year = 2008 | volume = 146 | issue = | pages = 657–668| doi = 10.1104/pp.107.112748| pmid = 18055583]

References

External links

*http://www.brain.riken.jp/labs/mdmd/pqq/