Photopolymerization of Dienoyl Lipids Creates Planar Supported Poly(lipid) Membranes with Retained Fluidity

Kristina S. Orosz, Ian W. Jones, John P. Keogh, Christopher M. Smith, Kaitlyn R. Griffin, Juhua Xu, Troy J. Comi, H. K. Hall, Steven S Saavedra

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

Polymerization of substrate-supported bilayers composed of dienoylphosphatidylcholine (PC) lipids is known to greatly enhance their chemical and mechanical stability; however, the effects of polymerization on membrane fluidity have not been investigated. Here planar supported lipid bilayers (PSLBs) composed of dienoyl PCs on glass substrates were examined to assess the degree to which UV-initiated polymerization affects lateral lipid mobility. Fluorescence recovery after photobleaching (FRAP) was used to measure the diffusion coefficients (D) and mobile fractions of rhodamine-DOPE in unpolymerized and polymerized PSLBs composed of bis-sorbyl phosphatidylcholine (bis-SorbPC), mono-sorbyl-phosphatidylcholine (mono-SorbPC), bis-dienoyl-phosphatidylcholine (bis-DenPC), and mono-dienoyl phosphatidylcholine (mono-DenPC). Polymerization was performed in both the Lα and Lβ phase for each lipid. In all cases, polymerization reduced membrane fluidity; however, measurable lateral diffusion was retained which is attributed to a low degree of polymerization. The D values for sorbyl lipids were less than those of the denoyl lipids; this may be a consequence of the distal location of polymerizable group in the sorbyl lipids which may facilitate interleaflet bonding. The D values measured after polymerization were 0.1-0.8 of those measured before polymerization, a range that corresponds to fluidity intermediate between that of a Lα phase and a Lβ phase. This D range is comparable to ratios of D values reported for liquid-disordered (Ld) and liquid-ordered (Lo) lipid phases and indicates that the effect of UV polymerization on lateral diffusion in a dienoyl PSLB is similar to the transition from a Ld phase to a Lo phase. The partial retention of fluidity in UV-polymerized PSLBs, their enhanced stability, and the activity of incorporated transmembrane proteins and peptides is discussed.

Original languageEnglish (US)
Pages (from-to)1577-1584
Number of pages8
JournalLangmuir
Volume32
Issue number6
DOIs
StatePublished - Feb 16 2016

Fingerprint

Fluidity
Photopolymerization
Membrane Lipids
Lipids
lipids
Polymerization
membranes
polymerization
Lipid bilayers
Phosphatidylcholines
Liquids
Membranes
liquid phases
Photobleaching
Rhodamines
Mechanical stability
Chemical stability
Substrates
Peptides
liquids

ASJC Scopus subject areas

  • Electrochemistry
  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Materials Science(all)
  • Spectroscopy

Cite this

Photopolymerization of Dienoyl Lipids Creates Planar Supported Poly(lipid) Membranes with Retained Fluidity. / Orosz, Kristina S.; Jones, Ian W.; Keogh, John P.; Smith, Christopher M.; Griffin, Kaitlyn R.; Xu, Juhua; Comi, Troy J.; Hall, H. K.; Saavedra, Steven S.

In: Langmuir, Vol. 32, No. 6, 16.02.2016, p. 1577-1584.

Research output: Contribution to journalArticle

Orosz, KS, Jones, IW, Keogh, JP, Smith, CM, Griffin, KR, Xu, J, Comi, TJ, Hall, HK & Saavedra, SS 2016, 'Photopolymerization of Dienoyl Lipids Creates Planar Supported Poly(lipid) Membranes with Retained Fluidity', Langmuir, vol. 32, no. 6, pp. 1577-1584. https://doi.org/10.1021/acs.langmuir.5b03437
Orosz, Kristina S. ; Jones, Ian W. ; Keogh, John P. ; Smith, Christopher M. ; Griffin, Kaitlyn R. ; Xu, Juhua ; Comi, Troy J. ; Hall, H. K. ; Saavedra, Steven S. / Photopolymerization of Dienoyl Lipids Creates Planar Supported Poly(lipid) Membranes with Retained Fluidity. In: Langmuir. 2016 ; Vol. 32, No. 6. pp. 1577-1584.
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