Development of the active site model for calcium-containing quinoprotein alcohol dehydrogenases

Shinobu Itoh, Hirokatsu Kawakami, Shunichi Fukuzumi

Research output: Contribution to journalArticlepeer-review

15 Scopus citations


A new PQQ model compound [dimethyl 7-(1,4,7,10-tetraoxa-13-azacyclopentadec-13-yl)carbonyl-4,5-dihydro-4,5-dioxo-1H-pyrrolo[2,3-f]quinoline-2,9-dicarboxylate, 1], in which a 1-aza-15-crown-5 group is attached through an amide linkage at the 7-position, has been synthesized in order to develop an efficient model system of calcium-containing quinoprotein alcohol dehydrogenases. It has been found that Ca2+ binds to the quinone most strongly among the alkaline earth metal ions examined (Ca2++>Sr2++>>Ba2++>>Mg2+) and the binding constant (K(M)) for Ca2+ is as large as 2.1x105 M-1. Formation of the C-5 hemiacetal derivatives with ethanol is also investigated spectrophotometrically to show that the alcohol-addition to the quinone is enhanced in the presence of the metal ions. In this case, Ca2+ and Sr2+ show a similar efficiency that is several times larger than that of Ba2+. Addition of a strong base such as DBU (1,8-diazabicyclo[5.4.0]undec-7-ene) into a MeCN solution containing the metal ion complex of 1 and ethanol leads to redox reactions to give the Ca2+ complex of 1H2 (quinol form) and acetaldehyde. Kinetic studies on the redox reactions have been performed to gain insight into the mechanism of the alcohol-oxidation reaction catalyzed by the metal complexes of coenzyme PQQ. Copyright (C) 2000 Elsevier Science B.V.

Original languageEnglish
Pages (from-to)85-94
Number of pages10
JournalJournal of Molecular Catalysis B: Enzymatic
Issue number1-3
StatePublished - 12 Jan 2000

Bibliographical note

Funding Information:
The present study was financially supported in part by a Grant-in-Aid for Scientific Research on Priority Area (Molecular Biometallics, 08249223 and 09235218) and a Grant-in-Aid for General Scientific Research (08458177) from the Ministry of Education, Science, Sports, and Culture of Japan.


  • Active site model
  • Calcium-containing quinoprotein alcohol dehydrogenase
  • Coenzyme PQQ


Dive into the research topics of 'Development of the active site model for calcium-containing quinoprotein alcohol dehydrogenases'. Together they form a unique fingerprint.

Cite this