Method of enzymatic determination of pyrroloquinoline quinone.
An improved enzymatic method for the determination of pyrroloquinoline quinone, a novel prosthetic group of some important oxidoreductases, has been developed with cytoplasmic membrane of Escherichia coli K-12, in which D-glucose dehydrogenase (EC 1.1.99.17) was completely resolved to apo-enzyme by EDTA treatment. Incubation of the EDTA-treated membrane with exogenous pyrroloquinoline quinone in the presence of magnesium ions gave a quantitative determination of pyrroloquinoline quinone by assaying the restored D-glucose dehydrogenase activity. This novel enzymatic method was confirmed to be highly reproducible up to 10 ng of pyrroloquinoline quinone and could be applied to a routine assay of pyrroloquinoline quinone.
D002462:Cell Membrane / Q000201:enzymology; D003067:Coenzymes / Q000032:analysis*; D004926:Escherichia coli / Q000201:enzymology; D005948:Glucose Dehydrogenases / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D045542:PQQ Cofactor; D011804:Quinolines / Q000032:analysis* / Q000494:pharmacology
D003067:Coenzymes; D011804:Quinolines; D045542:PQQ Cofactor; D005948:Glucose Dehydrogenases