Dynamic properties of isolated acetylcholine receptor proteins: release of calcium ions caused by acetylcholine binding.

• DOI: 10.1073/pnas.73.10.3364
• Publication Date: 2006-05-31T07:12:19Z
• Authors: H W Chang; E Neumann
• Keywords: Electrophorus

Interaction of Ca and acetylcholine (AcCh) ions with purified receptor (AcChR) from Torpedo californica Electrophorus electricus has been investigated in view these ions' role proposed bioelectricity. Spectrophotometric titration using murexide as an indicator ultrafiltration method 45Ca show that AcChR proteins have a high binding capacity for ions. Per macromolecule 260,000 daltons, up to 60 can be bound at least three dissociation constants. A linear inhibition AcCh by was observed the 0.1-1 mM range, indicating competition AcChR. The addition Ca-AcChR solution 1.2 causes release four six when maximum two are per dalton macromolecule. subsequent alpha-bungarotoxin reuptake These results suggest neural activator inhibitor induce opposing shifts between different conformational states isolated