Thromb Haemost 1991; 66(05): 598-603
DOI: 10.1055/s-0038-1646466
Original Article
Schattauer GmbH Stuttgart

Functional Ca2+ Channel Produced by Purified Platelet Membrane Glycoprotein IIb-IIIa Complex Incorporated into Planar Phospholipid Bilayer

Tetsuro Fujimoto
The Department of Internal Medicine, Research Institute for Nuclear Medicine and Biology, Hiroshima University, Hiroshima, Japan
,
Kingo Fujimura
The Department of Internal Medicine, Research Institute for Nuclear Medicine and Biology, Hiroshima University, Hiroshima, Japan
,
Atsushi Kuramoto
The Department of Internal Medicine, Research Institute for Nuclear Medicine and Biology, Hiroshima University, Hiroshima, Japan
› Author Affiliations
Further Information

Publication History

Received 05 November 1990

Accepted 07 May 1991

Publication Date:
25 July 2018 (online)

Summary

The ability of the platelet membrane glycoprotein (GP) IIb-IIIa complex to function as a Ca2+ channel was investigated by electrophysiological methods. The GPIIb-IIIa complex was purified with an electrically silent detergent, CHAPS, and reconstituted into liposomes. After incorporation of these liposomes to a planar phospholipid bilayer, Ba2+-permeable channel currents were detected. Since neither residual detergent nor dissociated GPIIb and IIIa produced any currents, the observed channel currents were attributed to the GPIIb-IIIa complex. These channel currents showed similar electrical properties with the Ca2+ channel previously described in platelet plasma membrane; a single channel conductance of approximately 10 pS in 53 mM Ba2+ solution and voltage-independency. It was concluded that the purified GPIIb-IIIa complex can act as a divalent cation-permeable channel in the artificial phospholipid bilayer.