Crystallization of p68 on lipid monolayers and as three-dimensional single crystals.
J Mol Biol
; 206(1): 213-9, 1989 Mar 05.
Article
en En
| MEDLINE
| ID: mdl-2704040
ABSTRACT
Two-dimensional crystals of p68, a Ca2+ -binding protein that has homology with members of the lipocortin/calpactin family, were obtained by interaction with a phospholipid monolayer. By measuring surface pressure at constant surface area, p68 was found to interact in a Ca2+ -dependent manner specifically with phosphatidylethanolamine, less so with phosphatidylserine and not at all with phosphatidylcholine. With dimyristoyl-phosphatidylethanolamine, two-dimensional crystalline arrays were formed. Image analysis of electron micrographs of these crystals, which diffracted to about 50 A, revealed p3 symmetry with a unit cell of about 178 A by 178 A; the protein densities showed a two-domain structure giving a cylindrical molecule of about 100 A by 35 A diameter packed as trimers. Three-dimensional microcrystals obtained without lipid or Ca2+ were suitable for electron microscopy and gave a tetragonal unit cell of about 256 A by 68 A. The implications of these observations on the structure and lipid specificity of p68 binding are discussed.
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Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Fosfolípidos
/
Proteínas de Unión al Calcio
Límite:
Humans
Idioma:
En
Revista:
J Mol Biol
Año:
1989
Tipo del documento:
Article
País de afiliación:
Reino Unido