Effect of insulin and glucagon on the mobility of ESR-probes incorporated in rat liver plasma membranes.
1. The effect of different concentrations of insulin (INS) and glucagon (GLU) on the rotational mobility of a membrane-incorporated spin probe 2,2-6,6-tetramethyl-4-capriloyl piperidine-1-oxil (C7) was investigated by electron spin resonance (ESR) technique. 2. Two strong adenylate cyclase effectors guanosine 5'-triphosphate (GTP) and guanylyl 5'-imidodiphosphate [Gpp(NH)p], as well as an antioxidant 4-methyl-2,6-ditretbutilphenol (AO) and a nonprotein hormone prostaglandin E2 (PGE2) were used as reference effectors. 3. Applied effectors reduced by 30-82% the rotation correlation time (TR) of the rat liver plasma membranes spin probe C7. The effect was time-dependent and reached saturation 30-40 min after the effector application. 4. The kinetic- and concentration-dependent changes in TR were described by a simple phenomenological model. The apparent binding constants and the number of the apparent membrane binding sites of the effectors used were calculated using the model.
Zlatanov
I
I
Central Lab of Biophysics, Bulgarian Academy of Sciences, Sofia.
Maltzeva
E
E
Borovok
N
N
Spassov
V
V
D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D002084:Butylated Hydroxytoluene / Q000494:pharmacology; D002210:Caprylates; D002462:Cell Membrane / Q000378:metabolism; D003497:Cyclic N-Oxides; D015232:Dinoprostone / Q000494:pharmacology; D004578:Electron Spin Resonance Spectroscopy; D004789:Enzyme Activation; D005934:Glucagon / Q000494:pharmacology*; D006160:Guanosine Triphosphate / Q000494:pharmacology; D006165:Guanylyl Imidodiphosphate / Q000494:pharmacology; D007328:Insulin / Q000494:pharmacology*; D007700:Kinetics; D008099:Liver / Q000166:cytology / Q000378:metabolism*; D008560:Membrane Fluidity / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D013113:Spin Labels
D002210:Caprylates; D003497:Cyclic N-Oxides; D007328:Insulin; D013113:Spin Labels; C083049:2,2,6,6-tetramethyl-4-capryloylpiperidine-1-oxyl; D002084:Butylated Hydroxytoluene; D006165:Guanylyl Imidodiphosphate; D006160:Guanosine Triphosphate; D005934:Glucagon; D000262:Adenylyl Cyclases; D015232:Dinoprostone