Metastable behaviour of saturated phosphatidylethanolamines: a densitometric study.
The specific volumes of saturated phosphatidylethanolamines having 12-18 carbon atoms per chain and the volume changes resulting from their temperature-induced phase transitions have been investigated using differential scanning densitometry. No dependence on acyl-chain length has been found for the molar volume changes associated with the Lc----L alpha transition, while the L beta----L alpha transition showed delta V-changes that increase with the length of the acyl-chains. The independence of acyl-chain length of the molar volume changes concomitant with the Lc----L alpha transition can be rationalized by the assumption that the volume changes result from the combined effects of hydration and acyl chain melting. An interesting corollary of the present studies is the disappearance of metastability at chain lengths of about 20-22 carbon atoms.
Koynova
R
R
Central Laboratory of Biophysics, Bulg. Acad. Sci., Sofia.
Hinz
H J
HJ
D002151:Calorimetry; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003720:Densitometry / Q000379:methods; D004355:Drug Stability; D010714:Phosphatidylethanolamines / Q000378:metabolism; D012996:Solutions; D013535:Suspensions; D013696:Temperature; D014867:Water
D010714:Phosphatidylethanolamines; D012996:Solutions; D013535:Suspensions; D014867:Water; C038089:1,2-distearoylphosphatidylethanolamine; C007510:1,2-dipalmitoyl-3-phosphatidylethanolamine