Reversible block of the calcium release channel/ryanodine receptor by protamine, a heparin antidote.
Mol Biol Cell
; 11(7): 2213-9, 2000 Jul.
Article
en En
| MEDLINE
| ID: mdl-10888663
Channel activity of the calcium release channel from skeletal muscle, ryanodine receptor type 1, was measured in the presence and absence of protamine sulfate on the cytoplasmic side of the channel. Single-channel activity was measured after incorporating channels into planar lipid bilayers. Optimally and suboptimally calcium-activated calcium release channels were inactivated by the application of protamine to the cytoplasmic side of the channel. Recovery of channel activity was not observed while protamine was present. The addition of protamine bound to agarose beads did not change channel activity, implying that the mechanism of action involves an interaction with the ryanodine receptor rather than changes in the bulk calcium concentration of the medium. The block of channel activity by protamine could be reversed either by removal by perfusion with buffer or by the addition of heparin to the cytoplasmic side of the channel. Microinjection of protamine into differentiated C(2)C(12) mouse muscle cells prevented caffeine-induced intracellular calcium release. The results suggest that protamine acts on the ryanodine receptor in a similar but opposite manner from heparin and that protamine can be used as a potent, reversible inhibitor of ryanodine receptor activity.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Bloqueadores de los Canales de Calcio
/
Protaminas
/
Quelantes
/
Canal Liberador de Calcio Receptor de Rianodina
/
Antagonistas de Heparina
/
Antídotos
Límite:
Animals
Idioma:
En
Revista:
Mol Biol Cell
Asunto de la revista:
BIOLOGIA MOLECULAR
Año:
2000
Tipo del documento:
Article
Pais de publicación:
Estados Unidos