RESUMEN
The ionic transport properties, capacitance and breakdown voltage of bilayer macrovesicles made from lecithin, dodecaprenol and their mixtures have been studied. The electrical measurements showed that polyprenol in lipid bilayers increases membrane permeability and elasticity, and decreases membrane thickness. Some physiological implications of these findings are indicated.
Asunto(s)
Membrana Dobles de Lípidos , Fosfatidilcolinas , Terpenos , Yema de Huevo , Modelos Biológicos , Permeabilidad , Fosfatidilcolinas/aislamiento & purificaciónRESUMEN
The content and type of dolichols in chicken embryo fibroblasts was estimated and the presence of enzymic activities of various dolichyl phosphate sugar transferases was documented. Chicken embryo fibroblasts effectively take up various polyprenoids from the culture medium and catalyse both formation of polyprenyl fatty acid esters and their hydrolysis. With fully unsatured polyprenols the hydrogenation of the terminal alpha-isoprene residue was observed. In baby hamster kidney cells the formation of mannolipids was enhanced by exogenous polyprenols.
Asunto(s)
Terpenos/metabolismo , Animales , Células Cultivadas , Embrión de Pollo , Cromatografía por Intercambio Iónico , Cromatografía en Capa Delgada , Cricetinae , Fibroblastos/metabolismo , Glucosiltransferasas/metabolismo , Metabolismo de los Lípidos , Manosa/metabolismo , Microsomas/metabolismo , Proteínas/metabolismoRESUMEN
Dolichyl phosphates of different chain length (C35, C55 , C75 , Dol-mixture of C90 , 95, 100, 105 and C110 ) were tested as lipid acceptors in transglycosylation reactions. In the absence of exogenously added dolichyl phosphates there were no differences in the rate of synthesis in liver of dolichyl phosphate mannose, dolichyl phosphate glucose and dolichyl pyrophosphate N-acetylglucosamine between normal and ethionine-treated animals. Addition of exogenous dolichyl phosphates of different chain length stimulated the synthesis of dolichyl phosphate mannose and dolichyl pyrophosphate N-acetyl-glucosamine 2 to 4 times depending on the chain length of dolichols , both in normal and ethionine-treated animals. In liver of ethionine-treated rats the formation of dolichyl phosphate glucose was not stimulated. Following ethionine treatment the concentration of free and esterified with fatty acids dolichols was increased.
