Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2010 Jul 21;99(2):595-9.
doi: 10.1016/j.bpj.2010.04.040.

Electric field-driven disruption of a native beta-sheet protein conformation and generation of a helix-structure

Pedro Ojeda-May  1 , Martin E Garcia
Affiliations

Electric field-driven disruption of a native beta-sheet protein conformation and generation of a helix-structure

Pedro Ojeda-May et al. Biophys J. .

Abstract

We demonstrate that an external constant electric field is able to modify the secondary structure of a protein and induce a transition from a beta-sheet into a helix-like conformation. This dramatic change is driven by a global rearrangement of the dipole moments at the amide planes. We also predict electric-field-induced modifications of the intermediate states of the protein.

PubMed Disclaimer

Figures

Figure 1
Figure 1
The dipoles of NH and OC in the amide plane give rise to a total dipole moment for each amino acid, which has the value 1.1 × 10−29 Cm.
Figure 2
Figure 2
(Color online) Free energy surface of the V3-loop as a function of the configurational energy E and the end-to-end distance Q for different strengths of the external electric field εE0: ε = 0.0, 0.4, 0.8, and 1.2. Local minima labeled as I1 and I2 correspond to intermediates. N1 refers to the native state in absence of field, which becomes metastable (I3) for ε = 0.8. Note the formation of a new global minimum N2 for the field strength ε = 1.2. U corresponds to the unfolded states. The temperature in all cases is T = Tf = 321 K.
Figure 3
Figure 3
(Color online) Coordinates in the (E, Q)-plane of the conformations yielding the maximal contribution to the partition function for ε = 0.0, 0.4, 0.8, and 1.2 and at different temperatures. The field strength is given by εE0 (see text). Note that for ε = 0.0 the observable structures lie around the point (E = − 135, Q = 5) (β-sheet) while for ε = 1.2 they are located near the point (E = –150, Q = 30) (helix). Dark (blue) and light (yellow) diamonds refer to low and high temperatures, respectively (see temperature scale).
Figure 4
Figure 4
(Color online) Ramachandran plot of the V3-loop for different strengths of the external electric field represented by the dimensionless factor ε (see text) at T = Tf = 321 K. The regions corresponding to helices and β-sheets are indicated.
Figure 5
Figure 5
The α-helix structure of the native state for a field strength of εE0 with εE0 = 5.16 × 108.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Etienne M.A., Aucoin J.P., Hammer R.P. Stoichiometric inhibition of amyloid β-protein aggregation with peptides containing alternating α,α-disubstituted amino acids. J. Am. Chem. Soc. 2006;128:3522–3523. - PubMed
    1. Kelly J.W. The alternative conformations of amyloidogenic proteins and their multi-step assembly pathways. Curr. Opin. Struct. Biol. 1998;8:101–106. - PubMed
    1. Lynn D.G., Meredith S.C. Review: Model peptides and the physicochemical approach to β-amyloids. J. Struct. Biol. 2000;130:153–173. - PubMed
    1. Laurén J., Gimbel D.A., Strittmatter S.M. Cellular prion protein mediates impairment of synaptic plasticity by amyloid-β oligomers. Nature. 2009;457:1128–1132. - PMC - PubMed
    1. Wada A. The α-helix as an electric macro-dipole. Adv. Biophys. 1976;9:1–63. - PubMed

LinkOut - more resources