Comparative Study of Insulin Chain-B in Isolated and Monomeric Environments under External Stress

Budi, Akin; Legge, Fiona S.; Treutlein, Herbert; Yarovsky, Irene

doi:10.1021/jp800350v

Cited by 38 publications

(51 citation statements)

References 42 publications

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“…47 Additionally, analysis of the SASA of proteins can be used to provide useful information of the protein potential ability to interact with the solvent and with others proteins. 47,48 As shown in Figure 5, the presence of the external field induced not only changes in the dipole moment but also significant increases in the SASA. Also in line with the trend in the flexibility of the proteins, it was observed that the potential induced larger changes in the SASA for Mb than for LSZ.…”

Section: Resultsmentioning

confidence: 99%

Adsorption of Soft and Hard Proteins onto OTCEs under the Influence of an External Electric Field

et al. 2015

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The adsorption behavior of hard and soft proteins under the effect of an external electric field was investigated by a combination of spectroscopic ellipsometry and molecular dynamics (MD) simulations. Optically transparent carbon electrodes (OTCE) were used as conductive, sorbent substrates. Lysozyme (LSZ) and ribonuclease A (RNase A) were selected as representative hard proteins whereas myoglobin (Mb), α-lactalbumin (α-LAC), bovine serum albumin (BSA), glucose oxidase (GOx), and immunoglobulin G (IgG) were selected to represent soft proteins. In line with recent publications from our group, the experimental results revealed that while the adsorption of all investigated proteins can be enhanced by the potential applied to the electrode, the effect is more pronounced for hard proteins. In contrast with the incomplete monolayers formed at open-circuit potential, the application of +800mV to the sorbent surface induced the formation of multiple layers of protein. These results also suggest that this effect can be related to the intrinsic polarizability of the protein (induction of dipoles), the resulting surface accessible solvent area (SASA), and structural rearrangements induced upon the incorporation on the protein layer. The described experiments are critical to understand the relationship between the structure of proteins and their tendency to form (under electric stimulation) layers with thicknesses that greatly surpass those obtained at open-circuit conditions.

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Section: Resultsmentioning

confidence: 99%

Adsorption of Soft and Hard Proteins onto OTCEs under the Influence of an External Electric Field

et al. 2015

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“…It has also been shown that electromagnetic radiation influences the glucose concentration, dielectric and electrical properties of the blood [29,30]. Electric field effect on insulin chain-B under static and oscillating conditions showed that the electric field caused a destabilizing effect on the peptide [31][32][33]. However, not much work has been done on the effects of cellular phone radiation at 850 MHz on the diabetic blood cells.…”

Section: Introductionmentioning

confidence: 99%

Case Study of High Blood Glucose Concentration Effects of 850 MHZ Electromagnetic Fields Using Gtem Cell

Boriraksantikul¹,

Bhattacharyya²,

Whiteside³

et al. 2012

PIER B

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Abstract-The effect of 850 MHz electromagnetic radiation on diabetic blood at 2 W and 60 W power levels was investigated and compared with normal blood cells. The power levels respectively represent radiations from a cell phone and the cell phone tower, both operating 850 MHz. A GTEM cell was designed for the tests to generate the desired uniform electromagnetic field and power in a shielded environment. Blood samples, having normal and high glucose concentrations, were placed in the usable area inside the GTEM cell for 10, 30, 60 minutes and the glucose levels and red and white blood cell viabilities were monitored and compared with the controls. Results show that the 850 MHz exposure significantly influences the blood cell counts and the glucose level in both normal and high glucose blood samples. In cell survivability analysis in normal blood samples it was found that the white blood cells are significantly higher than the control at 60 min exposure from cell phone radiation, while both the white and red blood cell are significantly higher following a 30 min exposure from tower radiation. For high glucose blood tests at 30 and 60 min exposure times, the tower radiation for 60 min and the cell phone radiation at both the exposure times show significantly changes in white blood cell counts, whereas there was no effect in red blood cells. Also, for 30 and 60 min exposure times, the glucose

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“…field strength of greater than 0.01 V/Å is required to perturb the zero field behavior of these molecules. [7–14] The presence of a field perturbs conformational states, due to localized residue‐specific dipolar orientation with the field altering hydrogen bonding arrangement dynamics and secondary and tertiary structure motifs, and enhancing sampling of peptide energy landscape as a result. The more rapid structural changes corresponding to shorter‐lived secondary and tertiary contacts increase the backbone fluctuations, rendering the more globular state of the peptide entropically and energetically favored.…”

Section: Discussionmentioning

confidence: 99%

“…[2–6] Bearing this in mind, molecular simulation provides one possible avenue for the unambiguous study of such effects. Recent work in this group,[7–9] as well as others,[10–14] has examined the athermal effects of electric and e/m fields on the structural stability of several enzymes and peptides. The hen egg white lysozyme (HEWL) simulations demonstrated the good stability of the enzyme across a range of field strengths and frequencies with field strengths in the region of 0.05 V/Å or greater required to disrupt the secondary structure of the protein (via perturbation of intra‐protein hydrogen bonds).…”

Section: Introductionmentioning

confidence: 99%

Effects of external electromagnetic fields on the conformational sampling of a short alanine peptide

2012

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Non-equilibrium molecular dynamics simulations of a solvated 21-residue polyalanine (A21) peptide, featuring a high propensity for helix formation, have been performed at 300 K and 1 bar in the presence of external electromagnetic (e/m) fields in the microwave region (2.45 GHz) and an r.m.s. electric field intensity range of 0.01-0.05 V/Å. To investigate how the field presence affects transitions between the conformational states of a protein, we report 16 independent 40 ns-trajectories of A21 starting from both extended and fully folded states. We observe folding-behavior of the peptide consistent with prior simulation and experimental studies. The peptide displays a natural tendency to form stable elements of secondary structure which are stabilized by tertiary interactions with proximate regions of the peptide. Consistent with our earlier work, the presence of external e/m fields disrupts this behavior, involving a mechanism of localized dipolar alignment which serves to enhance intra-protein perturbations in hydrogen bonds (English, et al., J. Chem. Phys. 2010, 133, 091105), leading to more frequent transitions between shorter-lifetime states.

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Comparative Study of Insulin Chain-B in Isolated and Monomeric Environments under External Stress

Cited by 38 publications

References 42 publications

Adsorption of Soft and Hard Proteins onto OTCEs under the Influence of an External Electric Field

Adsorption of Soft and Hard Proteins onto OTCEs under the Influence of an External Electric Field

Case Study of High Blood Glucose Concentration Effects of 850 MHZ Electromagnetic Fields Using Gtem Cell

Effects of external electromagnetic fields on the conformational sampling of a short alanine peptide

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