Quantitation by fast-atom bombardment mass spectrometry: assay of cytidine 3',5'-cyclic monophosphate-responsive protein kinase.
A protein kinase, stimulated by cytidine 3',5'-cyclic monophosphate, is conventionally assayed by monitoring the incorporation of radiolabelled phosphate from adenosine triphosphate into a histone substrate. Here the assay of the protein kinase is carried out by positive-ion fast-atom bombardment mass spectrometric analysis of the enzyme incubation mixture after the reaction has been terminated. The data so obtained show good agreement with data obtained by the conventional radiometric assay: the intrinsic advantage of the mass spectrometric assay is the capacity for multiple component monitoring; the ability of the kinase to bind competing cyclic nucleotides together with integral adenosine triphosphatase (ATPase) and phosphodiesterase activity can also be assessed.
Newton
R P
RP
Biochemistry Research Group, School of Biological Sciences, University College of Swansea, UK.
Khan
J A
JA
Brenton
A G
AG
Langridge
J I
JI
Harris
F M
FM
Walton
T J
TJ
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D003563:Cyclic CMP / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000201:enzymology; D011494:Protein Kinases / Q000032:analysis*; D051381:Rats; D016339:Spectrometry, Mass, Fast Atom Bombardment / Q000379:methods*
D003563:Cyclic CMP; D000255:Adenosine Triphosphate; D011494:Protein Kinases