Croatica Chemica Acta, Vol. 47 No. 3, 1975.
Conference paper
Regulatory Properties and Cooperativity of Membrane Bound Muscarinic Receptors of Intestinal Smooth Muscle Cells
Dida Kuhnen-Clausen
; Fraunhofer-Gesellschaft, Institut fur Aerobiologie, D 5949 Grafschaft/Sauerland, F. R. G.
Abstract
The regulatory properties of the membrane bound muscarinic
acetylcholine receptor (mAChR) of smooth muscles from the guinea
pig ileum are indicated by the S-shaped concentration-response
curve to acetyl-~-methylcholine (MeCh). Cooperativity upon receptor
activation is observed as well as cooperativity of heterotropic
ligands : two agonists, agonist-two antagonists and agonist-antagonist-
interaction. The cooperativity depends either on the integrity
of the cell membrane •structure or of the receptor protein.
Disordering of the membrane structure is caused by a cationic
detergent and results in a loss of sensitivity and cooperativity ·.of
the mAChR for the action of MeCh. Desensitization of the mAChR
results from the blockade of reactive SH-groups, but not from
reduced S-S-bonds. Structural differences between the mAChR
and the nicotinic receptor are discus•sed with respect to essential
disulfide bonds and reactive sulfhydryl groups.
Keywords
Hrčak ID:
196641
URI
Publication date:
3.12.1975.
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