Deflavination of flavo-oxidases by nucleophilic reagents.
Using spectroscopic techniques we studied the effect of the nucleophilic reagents cyanide, cyanate and thiocyanate on three flavo-oxidases namely alcohol oxidase (AO), glucose oxidase (GOX) and D-amino acid oxidase (DAOX). All three ions, added at concentrations in the mM range, caused release of the flavin adenine dinucleotide (FAD) co-factors from the enzyme molecules. In the case of AO this was accompanied by significant conformational perturbations, which was not observed for GOX and DAOX. As suggested from fluorescence, absorption and circular dichroism spectral changes at least one phenolic hydroxyl group became ionized upon FAD release from AO and a new class of Trp residues, fluorescent only in apo-AO protein, was demasked.
Zlateva
T
T
Department of Molecular Biology, University of Padua, Italy.
Boteva
R
R
Filippi
B
B
Veenhuis
M
M
van der Klei
I J
IJ
D000429:Alcohol Oxidoreductases / Q000737:chemistry; D002942:Circular Dichroism; D003485:Cyanates; D003486:Cyanides; D003605:D-Amino-Acid Oxidase / Q000737:chemistry; D005182:Flavin-Adenine Dinucleotide / Q000737:chemistry*; D005420:Flavoproteins / Q000737:chemistry*; D005949:Glucose Oxidase / Q000737:chemistry; D007202:Indicators and Reagents; D010088:Oxidoreductases / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013053:Spectrophotometry; D013861:Thiocyanates
D003485:Cyanates; D003486:Cyanides; D005420:Flavoproteins; D007202:Indicators and Reagents; D013861:Thiocyanates; D005182:Flavin-Adenine Dinucleotide; D010088:Oxidoreductases; D000429:Alcohol Oxidoreductases; C019643:alcohol oxidase; D005949:Glucose Oxidase; D003605:D-Amino-Acid Oxidase; C031760:thiocyanate