Special Issue "Protein Crystallization under the Presence of an Electric Field"
A special issue of Crystals (ISSN 2073-4352).
Deadline for manuscript submissions: 30 April 2017
Nowadays, the use of electrically-assisted protein crystallization methods by using direct current (DC) or alternating current (AC), has revealed that, on average, crystals grow better in crystal quality and oriented to the cathode (when the protein molecule was positively charged), compared to the crystals grown on the anode (which is a negatively charged protein molecule). These electro-assisted crystallization techniques also enable the growth of protein crystals, as a function of temperature, under the influence of DC or AC electric fields. It has also permitted the isolation of protein polymorphs, as published elsewhere. According to recent publications, AC current could affect not only the number of crystals, but also their size, depending on its frequency. Up to now, the trend in crystal growth for protein models studied is as follows: The higher the AC the higher the number of crystals; in the near future this can be applicable to the free electron lasers (XFEL) experiments for solving complicated protein structures using the fourth generation of synchrotrons all over the world. There have been a significant number of publications focused on this topic recently, which is why the thematic issue in “Protein Crystallization under the Presence of an Electric Field” for the Crystals journal (ISSN 2073-4352, http://www.mdpi.com/journal/crystals) will be published soon. We encourage all specialists and experts on this topic to submit original contributions to this journal, and to the thematic issue for consideration and publication.
Prof. Dr. Abel Moreno
Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. Papers will be published continuously (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.
Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are refereed through a peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Crystals is an international peer-reviewed Open Access monthly journal published by MDPI.
• Protein Electrocrystallization
• Electrochemically-assisted Protein Crystallization
• Crystal Growth under the Presence of Electric Currents (DC/AC)
The below list represents only planned manuscripts. Some of these manuscripts have not been received by the Editorial Office yet. Papers submitted to MDPI journals are subject to peer-review.
Title: Effect of an External Electric Field on the Kinetics of Dislocation-free Growth of Tetragonal Hen Egg White Lysozyme Crystals
Authors: Haruhiko Koizumi, Satoshi Uda, Kozo Fujiwara, Junpei Okada, and Jun Nozawa
Affiliation: Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
Abstract: We measured the growth rates of the tetragonal hen egg white (HEW) lysozyme crystal normal to the (110) and (101) faces with and without an external electric field at 1 MHz. The dislocation-free tetragonal HEW lysozyme crystals were grown from the seed crystal in a cell. We observed a decrease in the growth rates of the crystal measured under an applied field at 1 MHz although the overall driving force increased. By assuming that the birth and spread model of the two-dimensional nucleation occurs, moreover, we revealed an increase in the effective surface energy of the step under application of an external electric field at 1 MHz, leading to the improvement in the crystal quality of tetragonal HEW lysozyme crystals prepared in a 1 MHz applied field. This article also discusses an increase in the effective surface energy of the step in light of the change in the entropy of the solid.
Title: Electric Field Assisted Protein Crystallization Using Graphene-based Microfluidics
Authors: Shuo Suia, Yuxi Wanga, Yiliang Zhoub, Christos Dimitrakopoulosa, James Watkinsb, Kenneth Carterb, Sarah L. Perry*,a
Affiliations: a Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, MA, 01003, USA.
b Department of Polymer Science and Engineering, University of Massachusetts Amherst, Amherst, MA, 01003, USA.
Abstract: The presence of electric field has been shown to reduce the time for protein crystal nucleation and facilitate the growth of large, high quality crystals. Typically, these electro-crystallization studies have been performed using macroscale electrochemical cells that require the subsequent harvesting of crystals for analysis. Here, we utilize a microfluidic device platform that incorporates conductive grapheme films as electrodes to explore the electro-crystallization of various model proteins for use in the generation of samples for serial crystallography. This graphene-based microfluidic device not only allows electro-crystallization in a precisely-controlled geometry, but also provides a stable environment for, in situ X-ray analysis, without the need for cryocooling.
Title: Electro-infiltration of cytochrome C into porous silicon network and its effect on nucleation and protein crystallization. Studies of the electrical properties of porous Si layers system for applications in electron-transfer biomolecular devices.
Authors: Laura E. Serrano1, Mauricio Pacio1,* and Abel Moreno2, *
Affiliations:1 Instituto de Ciencias-CIDS Benemérita Universidad Autónoma de Puebla, Ed. 130 C, Col. San Manuel, C.P. 72570 Puebla, Pue. México; firstname.lastname@example.org, email@example.com
2 Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior C.U., México D.F. 04510, México; firstname.lastname@example.org, email@example.com
Abstract: In this work, we report the electrical properties of Cytochrome C (Cyt) inside porous silicon. M/PS-silane-coupling agent–Cyt/Si structures were formed using APTES or MPTMS as linkers for the Cyt electro-infiltrated in porous silicon layers, with 40, 50 and 60% of porosity. We first used two techniques of protein infiltration. These techniques were simple droop and electrochemical methods. The electrochemically-assisted cell used for the infiltration, improved the Cyt nucleation and the crystallization behavior due to the porous silicon. We could carry out the crystallization thanks to the previous infiltration of proteins inside the silicone pores network. After that, we continued with the protein crystal growth through vapor diffusion set-up. Secondly, we applied both forward and reverse bias current only to the infiltrated Cyt. Finally, the electrical characteristics were compared to the control (whose protein molecules were not infiltrated). The linker influenced the electrical properties, which showed a modification in the current density. The simple droop showed a current density around 3x10-6 A/cm2 and employing the electrochemical cell technique, the current density is shown around 135x10-3 A/cm2, as seen in the I-V characteristic curves.
Keywords: Cytochrome C nucleation and crystallization; protein infiltration, porous silicon; electrical properties; silanes, I-V characteristics.
Title: Macromolecular crystallization under electric field
Authors: Rubin 1,*, C. Owen *, K. Vish 2,3 and V. Stojanoff 3,*
Affiliations: 1 Accenture, New York
2 Siena College, Albany
3 National Synchrotron Light Source II, Upton
* National Synchrotron Light Source, Upton
Abstract: Electric fields have been employed to promote macromolecular crystallization since the 1990. Although crystals grown in electric fields seem to present higher diffraction quality the methods are not wide spread. We will review different configurations and present results for new geometries. The advantages and disadvantages of the different configurations are discussed in light of x-ray diffraction data.
Title: Crystal growth of high-quality protein crystals under the presence of strong magnetic field and an alternant electric field in pulse-wave mode.
Authors: Adela Rodriguez-Romero, Nuria Sturau-Escofet, Carina Pareja-Rivera and Abel Moreno
Affiliation: Institute of Chemistry, Universidad Nacional Autonoma de Mexico, Avenida Universidad 3000, Ciudad de Mexico 04510, Mexico.
Correspondence: firstname.lastname@example.org, email@example.com
Abstract: We have evaluated the effect of a strong magnetic field of 16.5 Tesla combined with radiofrequency pulses of 2Hz on the crystal growth of tetragonal hen egg white (HEW) lysozyme. The lysozyme crystals grown both in solution and in gel, under the influence of this strong magnetic field, produced large-size crystals and high-resolution structures. The protein crystals were compared in terms of crystal quality with controls. It has been demonstrated that a homogeneous magnetic field applied for a long time, reduces the gravity forces on the solution through the action of the magnetic force. This has a positive effect on the crystal growth processes where the convection is practically nullified, generating a situation like that found under the conditions of microgravity. The best results were obtained when protein crystals were grown in gels under the presence of this strong magnetic force for three-consecutive weeks. Subtle differences such as the number of the water molecules in the 3D structures or side chain flexibility for some amino acids were evaluated. The second part of this research was devoted to investigate the effect of alternate current (AC) in dense-disperse wave mode (pulse-wave) from 2 to 8 Hz on the crystal growth of lysozyme.