Effect of side chain structure on aggregation state and mechanical properties of synthetic polypeptide monolayers at the air-water interface

1993 ◽  
Vol 30 (1) ◽  
pp. 119-126 ◽  
Author(s):  
Tatsuya Tanizaki ◽  
Kyouta Hara ◽  
Atsushi Takahara ◽  
Tisato Kajiyama
Keyword(s):  
Mechanical Properties ◽  
Chain Structure ◽  
Side Chain ◽  
Water Interface ◽  
Aggregation State ◽  
Air Water Interface ◽  
Synthetic Polypeptide

scholarly journals Effect of Urea on Hydrophobic Side Chain Interactions in Polypeptides at the Air–Water Interface

1984 ◽  
Vol 57 (3) ◽  
pp. 873-874 ◽  
Author(s):  
Akira Shibata ◽  
Shinsuke Yamashita ◽  
Takuya Yamashita
Keyword(s):  
Side Chain ◽  
Water Interface ◽  
Air Water Interface

scholarly journals The interfacial structure and Young's modulus of peptide films having switchable mechanical properties

2007 ◽  
Vol 5 (18) ◽  
pp. 47-54 ◽  
Author(s):  
A.P.J Middelberg ◽  
L He ◽  
A.F Dexter ◽  
H.-H Shen ◽  
S.A Holt ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Self Assembly ◽  
Molecular Design ◽  
Foam Stability ◽  
Young's Modulus ◽  
Interfacial Structure ◽  
Water Interface ◽  
Air Water Interface ◽  
Peptide Dissociation

We report the structure and Young's modulus of switchable films formed by peptide self-assembly at the air–water interface. Peptide surfactant AM1 forms an interfacial film that can be switched, reversibly, from a high- to low-elasticity state, with rapid loss of emulsion and foam stability. Using neutron reflectometry, we find that the AM1 film comprises a thin (approx. 15 Å) layer of ordered peptide in both states, confirming that it is possible to drastically alter the mechanical properties of an interfacial ensemble without significantly altering its concentration or macromolecular organization. We also report the first experimentally determined Young's modulus of a peptide film self-assembled at the air–water interface ( E =80 MPa for AM1, switching to E <20 MPa). These findings suggest a fundamental link between E and the macroscopic stability of peptide-containing foam. Finally, we report studies of a designed peptide surfactant, Lac21E, which we find forms a stronger switchable film than AM1 ( E =335 MPa switching to E <4 MPa). In contrast to AM1, Lac21E switching is caused by peptide dissociation from the interface (i.e. by self-disassembly). This research confirms that small changes in molecular design can lead to similar macroscopic behaviour via surprisingly different mechanisms.

Linear and nonlinear microrheology of lysozyme layers forming at the air–water interface

Soft Matter ◽  
2014 ◽  
Vol 10 (36) ◽  
pp. 7051-7060 ◽  
Author(s):  
Daniel B. Allan ◽  
Daniel M. Firester ◽  
Victor P. Allard ◽  
Daniel H. Reich ◽  
Kathleen J. Stebe ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Water Interface ◽  
Nonlinear Mechanical ◽  
Air Water Interface ◽  
Linear And Nonlinear

Microrheology tracks the evolution in the linear and nonlinear mechanical properties of layers of the protein lysozyme adsorbing at the air–water interface as the layers undergo a viscoelastic transition.

scholarly journals Methylguanidinium at the Air/Water Interface: A Simulation Study with the Drude Polarizable Force Field

2020 ◽  
Author(s):  
Jian Zhu ◽  
Jing Huang
Keyword(s):  
Force Field ◽  
Model Compound ◽  
Side Chain ◽  
Water Interface ◽  
Polarizable Force Field ◽  
Polarization Effects ◽  
Structure And Dynamics ◽  
Arginine Side Chain ◽  
Air Water Interface ◽  
Dynamics Simulations

<div>Methylguanidinium is an important molecular ion which also serves as the model compound for arginine side chain. We studied the structure and dynamics of methylguanidium ion at the air/water interface by molecular dynamics simulations employing the Drude polarizable force field. We found out that methylguanidinium accumulate on the interface with a majority adopting tilted conformations. We also demonstrated that methylguanidinium and guanidinium ions have different preference towards the air/water interface. Our results illustrate the importance to explicitly include the electronic polarization effects in modeling interfacial properties.</div><div><br> </div>

Langmuir films and mechanical properties of polyethyleneglycol fatty acid esters at the air-water interface

2016 ◽  
Vol 498 ◽  
pp. 50-57 ◽  
Author(s):  
Stephanie Ortiz-Collazos ◽  
Yan M.H. Gonçalves ◽  
Bruno A.C. Horta ◽  
Paulo H.S. Picciani ◽  
Sonia R.W. Louro ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fatty Acid ◽  
Langmuir Films ◽  
Fatty Acid Esters ◽  
Water Interface ◽  
Air Water Interface ◽  
Acid Esters

scholarly journals Ubiquinones have surface-active properties suited to transport electrons and protons across membranes

1980 ◽  
Vol 185 (3) ◽  
pp. 715-722 ◽  
Author(s):  
Peter J. Quinn ◽  
Manouchehre A. Esfahani
Keyword(s):  
Fatty Acyl ◽  
Side Chain ◽  
Water Interface ◽  
Collapse Pressure ◽  
Phospholipid Monolayer ◽  
Ideal Mixing ◽  
Surface Active Properties ◽  
Air Water Interface ◽  
Surface Active ◽  
Ubiquinone 10

Surface-active properties of ubiquinones and ubiquinols have been investigated by monomolecular-film techniques. Stable monolayers are formed at an air/water interface by the fully oxidized and reduced forms of the coenzyme; collapse pressures and hence stability of the films tend to increase with decreasing length of the isoprenoid side chain and films of the reduced coenzymes are more stable than those of their oxidized counterparts. Ubiquinone with a side chain of two isoprenoid units does not form stable monolayers at the air/water interface. Mixed monolayers of ubiquinol-10 or ubiquinone-10 with 1,2-dimyristoyl phosphatidylcholine, soya phosphatidylcholine and diphosphatidylglycerol do not exhibit ideal mixing characteristics. At surface pressures less than the collapse pressure of pure ubiquinone-10 monolayers (approx. 12mN·m−1) the isoprenoid chain is located substantially within the region occupied by the fatty acyl residues of the phospholipids. With increasing surface pressure the ubiquinones and their fully reduced equivalents are progressively squeezed out from between the phospholipid molecules until, at a pressure of about 35mN·m−1, the film has surface properties consistent with that of the pure phospholipid monolayer. This suggests that the ubiquinone(ol) forms a separate phase overlying the phospholipid monolayer. The implications of this energetically poised situation, where the quinone(ol) is just able to penetrate the phospholipid film, are considered in terms of the function of ubiquinone(ol) as electron and proton carriers of energy-transducing membranes.

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