Atomic force microscopy study of protein-incorporating Langmuir-Blodgett films

Fujiwara, I.; Ohnishi, Michihiro; Seto, Jun’etsu

doi:10.1021/la00045a025

Cited by 54 publications

(21 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Moreover, transient structural ordering was revealed on the ultrashort time scale. For this complex system, UEC allowed us to picture the atomic forces involved in structural dynamics at far-from-equilibrium configurations, whose collective and coherent effects may otherwise be obscured.The resemblance of both lipid Langmuir films at water surfaces and Langmuir-Blodgett (LB) films to naturally occurring biological membranes means they often serve as model systems for studying membrane structures and properties, [3,4] such as head-group organization and hydration, [5] phase transitions, [6] interactions with membrane proteins, [7,8] and proton diffusion, [9] besides other applications in molecular electronics [10] and biological sensors.[11] Studies on the structure of lipid LB films have mostly been focused on fatty acids and fatty acid salts, [12] but for phospholipids, although more complex and less studied, their structures have been probed by a variety of techniques, including electron diffraction, [13][14][15] X-ray diffraction, [5,16] infrared spectroscopy, [17,18] scanning tunneling microscopy, [19] and atomic force microscopy. [20] Structural ultrafast dynamics have not been reported.…”

mentioning

confidence: 99%

Ultrafast Electron Crystallography of Phospholipids

Chen¹,

Seidel²,

Zewail³

2006

Angew Chem Int Ed

View full text Add to dashboard Cite

We report herein our first study on the structure and dynamics of mono-and bilayer phospholipids, the essential elements of biological membranes, by using ultrafast electron crystallography (UEC). [1,2] The phospholipid was immobilized as a Langmuir-Blodgett film on hydrophilic or hydrophobic silicon substrates. From the diffraction patterns we determined that the dimyristoyl phosphatidic acid (DMPA; Figure 1) molecules were aligned with their aliphatic chains perpendicular to the substrate surface, and resolved the subunit cell -CH 2 -CH 2 -CH 2 -distance to be c 0 = 2.54 . After a femtosecond temperature jump in the substrate we observed, through changes in the position and intensity of the diffraction, structural dynamics on different time scales: a coherent, non-equilibrium expansion (wave-type) along the aliphatic chains on the picosecond timescale, as well as contraction and restructuring at longer times. Moreover, transient structural ordering was revealed on the ultrashort time scale. For this complex system, UEC allowed us to picture the atomic forces involved in structural dynamics at far-from-equilibrium configurations, whose collective and coherent effects may otherwise be obscured.The resemblance of both lipid Langmuir films at water surfaces and Langmuir-Blodgett (LB) films to naturally occurring biological membranes means they often serve as model systems for studying membrane structures and properties, [3,4] such as head-group organization and hydration, [5] phase transitions, [6] interactions with membrane proteins, [7,8] and proton diffusion, [9] besides other applications in molecular electronics [10] and biological sensors.[11] Studies on the structure of lipid LB films have mostly been focused on fatty acids and fatty acid salts, [12] but for phospholipids, although more complex and less studied, their structures have been probed by a variety of techniques, including electron diffraction, [13][14][15] X-ray diffraction, [5,16] infrared spectroscopy, [17,18] scanning tunneling microscopy, [19] and atomic force microscopy. [20] Structural ultrafast dynamics have not been reported. Ultrafast optical spectroscopy has been used to probe the dynamics of water solvation, [21] and inelastic neutron scattering has enabled the deduction of time scales of collective motions from the dispersion relationships.[22] UEC is well suited for the study of structural changes because of its high sensitivity, low damage at low electron flux, [23] and spatiotemporal resolutions. All experiments were carried out in our UEC apparatus, [2,24] in which the electrons are incident at a grazing angle of q i = 0-58 and are scattered by the lipid molecules to form the diffraction patterns in the far field. The scattered electrons are recorded with a low-noise, imageintensified, charge-coupled device (CCD) camera assembly capable of single-electron detection.[23]The change of the structure was initiated by a femtosecond infrared laser pulse (800 nm, 120 fs, 1 kHz repetition rate) focused onto the sample surface at an inciden...

show abstract

mentioning

confidence: 99%

Ultrafast Electron Crystallography of Phospholipids

Chen¹,

Seidel²,

Zewail³

2006

Angew Chem Int Ed

View full text Add to dashboard Cite

show abstract

“…Atomic Force or Scanning Force Microscopy (SFM) appears to be a powerfull tool for imaging these systems at a molecular level. However, only few papers deal with imaging of mixed layers of proteins and fatty acids [19][20][21][22].…”

mentioning

confidence: 99%

Analysis by scanning force microscopy of enzyme-containing Langmuir-Blodgett films elaborated by a horizontal lifting method

Alexandre

Dubreuil

Fiol

et al. 1994

Microsc. Microanal. Microstruct.

View full text Add to dashboard Cite

“…Scanning force microscopy, with its different possibilities, is a unique tool for imaging these systems at a microscopic or at a molecular level. Few papers, however, dealing with imaging of mixed layers of proteins and fatty acids have been published [20][21][22][23][24][25][26].…”

mentioning

confidence: 99%