Failure to verify the presence of pyrroloquinoline quinone (PQQ) in bovine plasma amine oxidase by gas chromatography/mass spectrometry.
The presence of covalently bound pyrroloquinoline quinone (PQQ) in bovine plasma amine oxidase (BPAO) was examined by the use of gas chromatography/mass spectrometry. The enzyme was subjected to proteolysis with proteinase in the presence of [U-13C]PQQ as an internal standard. After isolation and derivatization of PQQ with phenyltrimethylammonium hydroxide, molecular peaks at m/z 448 and 462 were used for detection of PQQ and [U-13C]PQQ, respectively, by selected ion monitoring (SIM). In the SIM profile, although the sample extract obtained from BPAO treated with proteinase clearly showed the peak at m/z 462 for the internal standard, there were no peaks detectable at m/z 448, showing the absence of PQQ in the proteolysis digest of BPAO. Thus, our results do not support the claim that BPAO contains covalently bound PQQ in its structure.
Kumazawa
T
T
Department of Legal Medicine, Hamamatsu University School of Medicine, Japan.
Seno
H
H
Urakami
T
T
Suzuki
O
O
D006631:Amine Oxidase (Copper-Containing); D000818:Animals; D002417:Cattle; D003067:Coenzymes / Q000032:analysis; D004589:Electrophoresis, Disc; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D015394:Molecular Structure; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000097:blood* / Q000302:isolation & purification; D045542:PQQ Cofactor; D015363:Quinolones / Q000032:analysis*
D003067:Coenzymes; D015363:Quinolones; D045542:PQQ Cofactor; D006631:Amine Oxidase (Copper-Containing); D000587:Oxidoreductases Acting on CH-NH Group Donors