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|Title: ||Behaviour of NBD-head group labelled phosphatidylethanolamines in POPC bilayers: a molecular dynamics study|
|Authors: ||Filipe, Hugo A. L.|
Santos, Lennon S.
Prates Ramalho, J. P.
Moreno, Maria João
Loura, Luís M. S.
|Issue Date: ||2015|
|Citation: ||Filipe, Hugo A. L.; Santos, Lennon S.; Prates Ramalho, J. P.; Moreno, Maria João; Loura, Luís M. S.Behaviour of NBD-head group labelled phosphatidylethanolamines in POPC bilayers: a molecular dynamics study, Phys. Chem. Chem. Phys. 17, 20066-20079, 2015.|
|Abstract: ||A complete homologous series of fluorescent phosphatidylethanolamines (diCnPE), labelled at the head
group with a 7-nitrobenz-2-oxa-1,3-diazo-4-yl(NBD) fluorophore and inserted in 1-palmitoyl, 2-oleoyl-snglycero-
3-phosphocholine (POPC) bilayers, was studied using atomistic molecular dynamics simulations.
The longer-chained derivatives of NBD-diCnPE, with n = 14, 16, and 18, are commercially available, and
widely used as fluorescent membrane probes. Properties such as location of atomic groups and acyl chain
order parameters of both POPC and NBD-diCnPE, fluorophore orientation and hydrogen bonding,
membrane electrostatic potential and lateral diffusion were calculated for all derivatives in the series. Most
of these probes induce local disordering of POPC acyl chains, which is on the whole counterbalanced by
ordering resulting from binding of sodium ions to lipid carbonyl/glycerol oxygen atoms. An exception is
found for NBD-diC16PE, which displays optimal matching with POPC acyl chain length and induces
a slight local ordering of phospholipid acyl chains. Compared to previously studied fatty amines, acyl
chain-labelled phosphatidylcholines, and sterols bearing the same fluorescent tag, the chromophore in
NBD-diCnPE locates in a similar region of the membrane (near the glycerol backbone/carbonyl region) but
adopts a different orientation (with the NO2 group facing the interior of the bilayer). This modification
leads to an inverted orientation of the P–N axis in the labelled lipid, which affects the interface properties,
such as the membrane electrostatic potential and hydrogen bonding to lipid head group atoms. The
implications of this study for the interpretation of the photophysical properties of NBD-diCnPE (complex
fluorescence emission kinetics, differences with other NBD lipid probes) are discussed.|
|Other Identifiers: ||1463-9076|
|Appears in Collections:||CQE - Publicações - Artigos em Revistas Internacionais Com Arbitragem Científica|
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