Annexin V perturbs or stabilises phospholipid membranes in a calcium-dependent manner.
FEBS Lett
; 359(2-3): 155-8, 1995 Feb 13.
Article
en En
| MEDLINE
| ID: mdl-7867789
ABSTRACT
The potency of annexin V to transport Ca2+ ions across phospholipid membranes was investigated, using large unilamellar phospholipid vesicles loaded with the Ca2+ indicator fura-2. It was demonstrated that annexin V leaves the vesicle membranes intact when added in the presence of 1 mM Ca2+. However, if the vesicles were first incubated with annexin V in the absence of Ca2+, subsequent addition of Ca2+ produced a fluorescence signal due to binding of Ca2+ to fura-2. Centrifugation of the vesicle suspension immediately thereafter showed that this signal originated from the supernatant and not from the sedimented vesicles. Our results show that annexin V causes loss of vesicle integrity in the absence of Ca2+, and leakage of trapped fura-2, rather than inward Ca2+ transport. Bovine serum albumin or Ca2+ concentrations higher than 2.5 mM also caused such fura-2 leakage. Apparently, calcium-dependent binding of annexin V to the membrane prevents aspecific membrane damage caused by this protein.
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Base de datos:
MEDLINE
Asunto principal:
Fosfolípidos
/
Membrana Celular
/
Calcio
/
Anexina A5
Idioma:
En
Revista:
FEBS Lett
Año:
1995
Tipo del documento:
Article