Through diffusion measurements of molecules to a numerical model for protein crystallization in viscous polyethylene glycol solution

DOI: 10.3390/cryst12070881

Authors: Hiroaki Tanaka (Confocal Science Inc.) , Rei Utata (RIKEN Systems and Structural Biology Center) , Keiko Tsuganezawa (RIKEN Systems and Structural Biology Center; RIKEN Center for Biosystems Dynamics Research) , Sachiko Takahashi (Confocal Science Inc.) , Akiko Tanaka (Confocal Science Inc.; RIKEN Systems and Structural Biology Center; RIKEN Center for Biosystems Dynamics Research)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Crystals , VOL 12

State: Published (Approved)
Published: June 2022

Abstract: Protein crystallography has become a popular method for biochemists, but obtaining high-quality protein crystals for precise structural analysis and larger ones for neutron analysis requires further technical progress. Many studies have noted the importance of solvent viscosity for the probability of crystal nucleation and for mass transportation; therefore, in this paper, we have reported on experimental results and simulation studies regarding the use of viscous polyethylene glycol (PEG) solvents for protein crystals. We investigated the diffusion rates of proteins, peptides, and small molecules in viscous PEG solvents using fluorescence correlation spectroscopy. In high-molecular-weight PEG solutions (molecular weights: 10,000 and 20,000), solute diffusion showed deviations, with a faster diffusion than that estimated by the Stokes–Einstein equation. We showed that the extent of the deviation depends on the difference between the molecular sizes of the solute and PEG solvent, and succeeded in creating equations to predict diffusion coefficients in viscous PEG solutions. Using these equations, we have developed a new numerical model of 1D diffusion processes of proteins and precipitants in a counter-diffusion chamber during crystallization processes. Examples of the application of anomalous diffusion in counter-diffusion crystallization are shown by the growth of lysozyme crystals.

Journal Keywords: protein crystallization; nucleation; viscosity; diffusion; PEG; FCS; counter-diffusion; self-searching; crystallization scenario

Subject Areas: Biology and Bio-materials, Technique Development


Instruments: I04-Macromolecular Crystallography

Added On: 27/06/2022 11:20

Documents:
crystals-12-00881.pdf

Discipline Tags:

Technique Development - Life Sciences & Biotech Structural biology Life Sciences & Biotech

Technical Tags:

Diffraction Macromolecular Crystallography (MX)