DNA initiates polymorphic structural transitions in lecithin

FEBS Letters

Ivanitsky, G.R.¹  Dawson, A.K.²  Gorelov, A.V.¹  Tarahovsky, Y.S.¹  Deev, A.A.¹  Nicolaeva, T.I.¹  Khusainova, R.S.¹ 

[1] Institute of Theoretical and Experimental Biophysics, Pushchino, Russian Federation;Centre for Soft Condensed Matter and Biomaterials, University College, Dublin, Ireland

关键词: DNA-lipid interaction;    Transfection;    Lipid polymorphism;    Membrane ultrastructure;    DPPC;    dipalmitoylphosphatidylcholine;    DSC;    differential scanning calorimetry;   

DOI  :  10.1016/0014-5793(96)00643-6

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The inverted micellar phase, obtained by treating lecithin and Ca²⁺-DNA complex with chloroform, was used as an intermediate step in the preparation of DNA-Ca²⁺-lecithin complex. DSC analysis demonstrated the involvement of a large fraction of lipid in the interaction with DNA. Freeze-fracture electron microscopy revealed (i) rod-like structures on the hydrophobic fracture surface of membranes and (ii) regular bundles of fibrils with a repeat distance of about 6 nm, which were located free in solution. Similar regular bundles of fibrils were also revealed by staining the samples with uranyl acetate. According to the suggested model, the observed structures are hexagonally packed inverted lipid tubes, with DNA located in their central cores. The possible biological relevance of the capability of Ca²⁺-DNA to initiate polymorphic phase transitions of lecithin is discussed.

【 授权许可】

Unknown