Structural properties of the cAMP-dependent protein kinase associated with rat synaptic plasma membranes--I. Configuration in situ and membrane association-derived influences on [3H]cAMP binding.
1. A geometry of molecular ordering in situ characterizes the synaptosomal membrane-bound cAMP kinase, which is revealed from the expression of two equal-size [3H]cAMP-binding domains of differing sensitivity to physical (freeze-thaw) and chemical (reconstitution following salt-effected peripheral protein depletion) treatment of the membrane. 2. Cross-linking of rat synaptosomal membrane proteins with glutaraldehyde revealed after electrophoretic (agarose-polyacrylamide-SDS) resolution and "Western blot" transfer a series of bands with in situ (i.e. on the Western blots) [3H]cAMP-binding capacity. The molecular sizes of these protein bands corresponded closely with those of the cAMP kinase subunit assemblies (R2C2)2, (R2C)2, R2C2, R2C and RC. 3. The subunit assembly (R2C2)2 was also revealed after cross-linking with glutaraldehyde of the purified (commercial preparation) cytosol-derived cAMP kinase II reconstituted in lecithin liposomes. 4. The results support consideration of an operative in vivo configurational shifting between assembly forms and are discussed in the light of the outlined possibility that such shiftings might be involved in the regulation of the membrane-bound cAMP kinase.
Papaphilis
A D
AD
Department of Experimental Physiology, University of Athens, School of Medicine, Greece.
Kotsifaki
H E
HE
D000818:Animals; D015153:Blotting, Western; D003432:Cross-Linking Reagents; D000242:Cyclic AMP / Q000378:metabolism*; D005976:Glutaral; D008081:Liposomes; D008970:Molecular Weight; D011494:Protein Kinases; D051381:Rats; D011919:Rats, Inbred Strains; D012995:Solubility; D013570:Synaptic Membranes / Q000201:enzymology*
D003432:Cross-Linking Reagents; D008081:Liposomes; D000242:Cyclic AMP; D011494:Protein Kinases; D005976:Glutaral