An electrically assisted device for protein crystallization in a vapor-diffusion setup

Abstract

A new easy-to-use device has been designed and implemented for electric field-induced protein crystallization in a vapor-diffusion configuration. The device not only controls crystal nucleation by means of the electrical current, but also favors crystal growth owing to its vapor-diffusion setup. Crystallization was conducted in the presence of an internal electric field and direct current. The proteins investigated were lysozyme, as model protein, and 2TEL-lysozyme (a synthetic protein consisting of two tandem alpha helix motifs connected to a lysozyme moiety). Lysozyme crystals that grew attached to the cathode were larger than those grown attached to the anode or in the absence of an electric current. On the other hand, crystals of 2TEL-lysozyme qualitatively showed a better X-ray diffraction pattern when grown in the presence of an electric current.

Recent Insights into the Crystallization Process; Protein Crystal Nucleation and Growth Peculiarities; Processes in the Presence of Electric Fields

“…Such ITO-covered-glass-electrodes have been widely used in subsequent studies of Moreno's group. For instance, the electrodes have been adapted to a sitting-drop vapor-diffusion crystallization setup applied for lysozyme and 2TEL-Lys crystallization [13]. As observed by the authors, the lysozyme crystals growing while attached to the cathode are larger than those grown in the absence of an electric current.…”

“…Pioneered by Aubry's group [4,5] some 20 years ago, protein crystallization under EF attracts an increasing attention, becoming a mature scientific branch today. Major contributions in this research field have been made by the teams of Moreno [6][7][8][9][10][11][12][13][14][15][16][17], Koizumi [18][19][20][21][22][23][24][25][26][27][28][29], Veesler [30][31][32][33], etc. (the list is not exhaustive).…”

A Graphene-Based Microfluidic Platform for Electrocrystallization and In Situ X-ray Diffraction

“…The presence of an electric field during protein crystallization has been shown to affect both the rate of nucleation and the rate of crystal growth by controlling the local concentration and concentration gradients of proteins and the associated crystallization reagents [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. These methods have the potential to improve the success rate associated with protein crystallogenesis and enhance our understanding of the structure-function relationship in challenging biomacromolecular targets.…”

“…Electrocrystallization platforms have been reported for a variety of crystallization schemes, including batch [6][7][8][9][10][11][14][15][16][17][18][19][20], vapor diffusion [5,[13][14][15][16], and counter-diffusion [21], taking advantage of both internal [6,7,[12][13][14][19][20][21][22] and external electric fields [5,[8][9][10]15,18,23]. These strategies have also explored the effects of constant (DC) [5][6][7][13][14][15][16][17][20][21][22] and alternating (AC) electric fields [8][9][10]...…”

“…These strategies have also explored the effects of constant (DC) [5][6][7][13][14][15][16][17][20][21][22] and alternating (AC) electric fields [8][9][10][11][12][16][17][18]. However, the benefits observed for the various electrode arrangements and crystallization setups reported to date have been limited by the need to manually harvest crystals for subsequent diffraction analysis.…”