Infrared studies of fully hydrated unsaturated phosphatidylserine bilayers. Effect of lithium and calcium

Par Conseil national de recherches du Canada

DOI	Trouver le DOI : https://doi.org/10.1021/bi00397a030
Auteur	Rechercher : Casal, H. L.¹; Rechercher : Martin, A.¹; Rechercher : Mantsch, H. H.¹; Rechercher : Paltauf, F.; Rechercher : Hauser, H.
Affiliation	Conseil national de recherches du Canada
Format	Texte, Article
Résumé	Infrared spectroscopy has been used to characterize the thermal-phase behavior of fully hydrated 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-~-serine (POPS) and 1,2-dioleoyl-sn-glycero-3-phospho-~-serine (DOPS) as well as their interaction with Li⁺ and Ca2⁺. The order-disorder transition of POPS-NH₄⁺ is at 17ºC; in the presence of Li+ a POPS-Li⁺ complex is formed, and the transition temperature of this complex is 40ºC. DOPS-NH₄+ has an order-disorder transition at -11ºC, and unlike POPS the addition of Li⁺ has no effect on the thermal behavior of DOPS-NH₄⁺. This indicates that the binding of Li⁺ to DOPS is negligible or very weak. Li⁺ binds to the phosphate and carboxylate groups of POPS, and as a result these groups lose their water of hydration. Li⁺ binding induces a conformational change, probably in the glycerol backbone of POPS; however, the conformation of the two P-0 ester bonds remains gauche-gauche as in POPS-NH4⁺. Both POPS and DOPS form crystalline complexes with Ca²⁺. As a result of Ca²⁺ binding to the phosphate, this group loses its water of hydration and there is a conformational change in the P-0 ester bonds from gauche-gauche to antiplanar-antiplanar. In contrast to the POPS-Li⁺ complex, the carboxylate group remains hydrated in the Ca²⁺ complexes. Furthermore, in these PS-Ca²⁺ complexes a new hydrogen bond is formed between one of the ester C=O groups and probably water. Such a situation is not found in the NH₄⁺ and Li⁺ salts of phosphatidylserine.
Date de publication	1987-11
Dans	Biochemistry 26, nº 23 : 7395–7401.
Langue	anglais
Publications évaluées par des pairs	Oui
Numéro du CNRC	CASAL1987A NRCC 28178
Numéro NPARC	9364798
Exporter la notice	Exporter en format RIS
Signaler une correction	Signaler une correction (s'ouvre dans un nouvel onglet)
Identificateur de l’enregistrement	c0fbcbcf-3974-4d08-807e-b1007fcc7218
Enregistrement créé	2009-07-10
Enregistrement modifié	2020-03-17

Date de modification :: 2024-09-29