Title:	Modulated phases of phospholipid bilayers induced by tocopherols
Authors:	Kamal, Md. Arif Raghunathan, V.A.
Keywords:	Phospholipid bilayer Tocopherol X-ray diffraction
Issue Date:	Nov-2012
Publisher:	Elsevier B.V.
Citation:	Biochimica et Biophysica Acta , 2012, Vol. 1818, p2486
Abstract:	The influence of α-, γ‐ and δ-tocopherols on the structure and phase behavior of dipalmitoyl phosphatidylcholine (DPPC) bilayers has been determined from X-ray diffraction studies on oriented multilayers. In all the three cases the main-transition temperature (Tm) of DPPC was found to decrease with increasing tocopherol concentration up to around 25 mol%. Beyond this the main transition is suppressed in the case of γ‐tocopherol, whereas Tm becomes insensitive to composition in the other two cases. The pre-transition is found to be suppressed over a narrow tocopherol concentration range between 7.5 and 10 mol% in DPPC‐γ-tocopherol and DPPC-δ‐tocopherol bilayers, and the ripple phase occurs down to the lowest temperature studied. In all the three cases a modulated phase is observed above a tocopherol concentration of about 10 mol%, which is similar to the Pβ phase reported in DPPC–cholesterol bilayers. This phase is found to occur even in excess water conditions at lower tocopherol concentrations, and consists of bilayers with periodic height modulation. These results indicate the ability of tocopherols to induce local curvature in membranes, which could be important for some of their biological functions
Description:	Restricted Access.
URI:	http://hdl.handle.net/2289/5336
ISSN:	0006-3002
Alternative Location:	http://dx.doi.org/10.1016/j.bbamem.2012.06.016
Copyright:	2012 Elsevier B.V.
Appears in Collections:	Research Papers (SCM)

Items in RRI Digital Repository are protected by copyright, with all rights reserved, unless otherwise indicated.