Spectrophotometric ribonuclease assays using dinucleoside monophosphate substrates.
A pair of ribonuclease assays have been developed which offer improvements in specificity, simplicity, and/or sensitivity over current procedures. The assays measure the rate of adenosine release upon ribonuclease hydrolysis of 3'-adenosyl dinucleoside monophosphate substrates. Adenosine formation is spectrophotometrically determined by combining a coupled-enzyme system (adenosine deaminase or an adenosine deaminase/nucleoside phosphorylase/xanthine oxidase combination) to the ribonuclease cleavage. As demonstrated by a brief characterization of the ribonuclease activities in several mouse tissues, the methods demonstrate the advantage of being able to discriminate between ribonucleases of differing substrate specificities. An interesting guanosyl(3'-5')adenosine-specific ribonuclease in mouse brain has been identified using these assay methods.
Postek
K M
KM
Department of Chemistry, State University of New York, Plattsburgh 12901.
LaDue
T
T
Nelson
C
C
Sandwick
R K
RK
D000818:Animals; D015226:Dinucleoside Phosphates / Q000737:chemistry*; D051379:Mice; D009928:Organ Specificity; D012260:Ribonucleases / Q000032:analysis*; D013056:Spectrophotometry, Ultraviolet; D013379:Substrate Specificity
D015226:Dinucleoside Phosphates; D012260:Ribonucleases