Top (left) and cross-sectional (right)
views of snapshots of final simulation structures of NeuTM35 peptide
in mixed DMPC-DDPC bilayers. Average DMPC composition
is 55.8%. Green, blue, and red represent
peptide, DMPC, and DDPC respectively. Phosphorus atoms are shown as
spheres in the right-hand panels. Water is omitted for clarity
The hydrophobic matching effects between a transmembrane helical
peptide and a binary phospholipid bilayer have
been studied using GLMLi. Atomistic
simulations have been performed of the NeuTM35 peptide embedded at a
fixed perpendicular angle within a series of bilayers containing
DMPC mixed with lipids having acyl tails that are shorter by four
carbons (DDPC) or longer by four carbons (DSPC).
Strong hydrophobic matching patterns are observed in
DMPC-DDPC systems over a range of mixture compositions, with both
DMPC content and bilayer thickness increasing with proximity to the
peptide. While inclusion of the peptide increased mean SCD
order parameters of both lipid components’ tails, the enrichment of
DMPC in the immediate neighborhood of the peptide is reflected in a
greater ordering for DMPC than DDPC. Much weaker influence of the
peptide on bilayer thickness and local composition was observed in
DSPC-DMPC systems, where DSPC content is very slightly enhanced near
the peptide and little difference is seen between the effects of
peptide insertion on the two components’ order parameters.
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