Enzymatic preparation of carboxyl oxygen-18 labeled prostaglandin F2α and utility for quantitative mass spectrometry

WC Pickett, RC Murphy - Analytical Biochemistry, 1981 - Elsevier
WC Pickett, RC Murphy
Analytical Biochemistry, 1981Elsevier
A nonspecific liver esterase was found to not only catalyze the hydrolysis of the methyl ester
of prostaglandin F2α (PGF2α) but also to catalyze the exchange of the carboxyl oxygen
atoms with water leading to the production of [18O2] PGF2α when the enzymatic hydrolysis
is carried out in H218O. The kinetics of this oxygen-18 exchange reaction are briefly
discussed. The [18O2] PGF2α was found to be relative stable toward back exchange in
methanol, aqueous buffer, and urine, but rapidly back exchanged to the native PGF2α in …
A nonspecific liver esterase was found to not only catalyze the hydrolysis of the methyl ester of prostaglandin F2α (PGF2α) but also to catalyze the exchange of the carboxyl oxygen atoms with water leading to the production of [18O2]PGF2α when the enzymatic hydrolysis is carried out in H218O. The kinetics of this oxygen-18 exchange reaction are briefly discussed. The [18O2]PGF2α was found to be relative stable toward back exchange in methanol, aqueous buffer, and urine, but rapidly back exchanged to the native PGF2α in plasma with a half-life of 1 h. The [18O2]PGF2α was relatively stable in plasma to which alcohol had been added. The utility of the oxygen-18 labeled prostaglandin as an internal standard in a gas chromatography-mass spectrometry assay was demonstrated at the picomole range.
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