Micromanipulation of phospholipid bilayers by atomic force microscopy.
The molecular details of adhesion mechanics in phospholipid bilayers have been studied using atomic force microscopy (AFM). Under tension fused bilayers of dipalmitoylphosphatidylcholine (DPPC) yield to give non-distance dependent and discrete force plateaux of 45.4, 81.6 and 113+/-3.5 pN. This behaviour may persist over distances as great as 400 nm and suggests the stable formation of a cylindrical tube which bridges the bilayers on the two surfaces. The stability of this connective structure may have implications for the formation of pili and hence for the initial stage of bacterial conjugation. Dimyristoylphosphatidylcholine (DMPC) bilayers also exhibit force plateaux but with a much less pronounced quantization. Bilayers composed of egg PC, sterylamine and cholesterol stressed in a similar way show complex behaviour which can in part be explained using the models demonstrated in the pure lipids.
Maeda
Nobuo
N
Department of Applied Mathematics, Research School of Physical Sciences and Engineering, The Australian National University, Canberra, Australia.
Senden
Tim J
TJ
di Meglio
Jean-Marc
JM
D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry; D066298:In Vitro Techniques; D008051:Lipid Bilayers / Q000737:chemistry*; D008081:Liposomes / Q000737:chemistry; D008563:Membrane Lipids / Q000737:chemistry; D018625:Microscopy, Atomic Force; D008956:Models, Chemical; D010743:Phospholipids / Q000737:chemistry*; D014867:Water / Q000737:chemistry
D008051:Lipid Bilayers; D008081:Liposomes; D008563:Membrane Lipids; D010743:Phospholipids; D014867:Water; D015060:1,2-Dipalmitoylphosphatidylcholine; D004134:Dimyristoylphosphatidylcholine