Abstract
Tissue specificity to (cyclic 3', 5')-AMP (CAMP) binding protein and protein kinase was studied with disc electrophoresis.
Soluble fractions of rat tissue were incubated with H3-CAMP and separated by disc electrophoresis of 7.5% gel. Each gel was sliced into 30, extracted with 30% H2O2 and 1N NaOH, and their radioactivity was counted. Although every tissue shows a specific pattern to radioactivity, three common peaks were observed on liver, spleen, kidney, etc.. Those CAMP binding components were differentiated by Rf-ratio on disc electrophoresis: stomach type of peak at 0.76, adrenal type at 0.43, and muscle type at 0.30.
Cyclic AMP dependent protein kinases were also studied on the soluble fraction of rat gastric mucosa and liver. On the gastric mucosa, a single peak of CAMP dependent protein kinase was detected at the slice number 14 to 16. On the liver, two peaks at the slice number 1 and 7 to 10. Dissociation from CAMP dependent protein kinases are observed by incubation of each soluble fraction with additional CAMP (10-5M) prior to electrophoretic separation. On the gastric mucosa, the peak of CAMP dependent protein kinase changed its mobility on disc electrophoresis and moved to the place of free type protein kinase at the slice number 1 and 7 to 9. On the liver, the same phenomenon was observed and they moved to the slice number 1 and 3 to 6.
With those findings on rat gastric mucosa and liver, tissue specific and electrophoretically different subunits are suspected to be the cyclic AMP binding protein and protein kinase, which compose each tissue specific cyclic AMP dependent protein kinase.
