Influence of GHz electric fields on the mechanical properties of a microtubule

Abstract

The effects of external GHz electric fields on the mechanical properties of a microtubule (MT) have been modeled through the application of a molecular dynamics simulation method. To explore the properties of the MT, two different systems each consisting of a pair of dimers were exposed to an 0.03 V/nm electric field with a frequency ranging between 1 to 10 GHz. It was found that the Young's modulus of each system, which is related to the flexibility of the MT, was lower at some frequencies and higher at others in comparison with normal biological conditions. Hence, the application of such an electric field with a frequency in this range may affect MT function, which could have positive or negative effects on cell health. Positive effects include its potential use in cancer treatment, where the application of such a field could lead to a decrease in MT rigidity, similar to the effect of Taxol on MTs. Negative effects include unwanted changes to the mechanical properties of MTs (e.g., disturbing the cell division process and in turn increasing the risk of cancer) upon the application of such a field.

Molecular modeling of oscillating GHz electric field influence on the kinesin affinity to microtubule

“…Reducing the flexibility of the proteins due to applying the GHz electric fields has been reported in our previous studies. [19][20][21] Since the average time of the kinesin motion on the microtubule is related to the SF value, it is expected that exposing the system to the external GHz electric field leads to the decrease of this average time.…”

“…To consider the influence of the application of oscillating field on MT, these systems were exposed to a periodic electric field E = E 0 cos(ωt), where E 0 is the electric field amplitude of 0.03 V/nm, which is proportional to membrane potential and the values of field strength similar to those in some experimental and computational studies are adopted. [14,[18][19][20][21] The frequency of field, ω, is set separately at 1, 2, . .…”

“…[12] Since biological systems such as proteins have polar or charged groups, investigating the effects of external electromagnetic fields (EMFs), which arise from sources such as cell phones, on the operations of these biological systems seems important. [13][14][15][16][17][18][19][20][21][22] In this paper, the effect of an external electric field on the kinesin affinity to the microtubule is investigated in the presence of ATP and ADP and in the absence of such nucleotides. It is found that exposing the kinesin to the external GHz electric field changes the kinesin affinity to the microtubule.…”

Cytoskeletal Disruption after Electroporation and Its Significance to Pulsed Electric Field Therapies

“…Electric fields have also been shown to disrupt MT polymerization, which is exploited as the mechanism of action of tumor treating fields (TTFields) that use low-magnitude (<2.5 V/cm) fields applied at 100−300 kHz [122]. Molecular dynamics simulations also indicate that electric fields of GHz frequencies can disrupt tubulin and tubulin associated proteins [123][124][125]. Adding to the existing literature on MT dynamics under electric fields, recent molecular dynamics studies and experimental studies now demonstrate that PEFs can directly disrupt MTs.…”

Electro-opening of a microtubule lattice in silico

“…Most of the investigations have been performed in silico [22] , where they explored either membrane [23] or protein systems. The effect of the electric field was mostly on the secondary structure, conformation, and orientation of various proteins [24] , [25] , [26] , [27] , [28] , [29] , [30] , [31] , [32] , [33] , [34] , [35] , [36] , [37] , [38] , [39] , [40] , [41] , [42] , including cytoskeletal system proteins such as tubulin [43] , [44] , [45] , [46] , [47] and kinesin [48] , even leading to the unfolding of some proteins [49] , [50] , [51] . Most of this work explored electric field effects either in a single protein or membrane-bound proteins systems.…”