Abstract
The application of five water-soluble, halogen-free, alkylammonium-based ionic liquids (ILs) as additives for advanced crystallization of lysozyme was investigated. Their biocompatibility was determined by long-term measurement of the overall mean relative enzyme activities. These were maximally reduced by about 10–15% when up to 200 g IL l−1 was added. Sitting-drop vapor diffusion crystallization experiments revealed that the addition of some of the ILs led to less crystal polymorphism and precipitation was avoided reliably even at larger NaCl concentrations. The addition of ILs tended to result in larger crystals. The kinetics of lysozyme crystallization were significantly enhanced using ILs as crystallization additives, e.g. by a factor of 5.5 when 100 g ethanolammonium formate l−1 was added. ILs with “soft” anions, such as formate or glycolate, were superior to ILs with “hard” anions, like nitrate.
Similar content being viewed by others
References
Basu SK, Govardhan CP, Jung CW, Margolin AL (2004) Protein crystals for the delivery of biopharmaceuticals. Expert Opin Biol Ther 4:301–317
Bergfors TM (ed) (1999) Protein crystallization: techniques, strategies, and tips. A laboratory manual. International University Line, Biotechnology Series, La Jolla
Cvetkovic A, Picioreanu C, Straathof AJJ, Krishna R, van der Wielen LAM (2005) Quantification of binary diffusion in protein crystals. J Phys Chem B 109:10561–10566
Garlitz LA, Summers CA, Flowers RA, Borgstahl GEO (1999) Ethylammonium nitrate: a protein crystallization reagent. Acta Cryst D 55:2037–2038
Howard SB, Twigg PJ, Baird JK, Meehan EJ (1988) The solubility of hen egg-white lysozyme. J Cryst Growth 90:94–104
Lange C, Patil G, Rudolph R (2005) Ionic liquids as refolding additives: N´-alkyl and N′-(ω-hydroxyalkyl) N-methylimidazolium chlorides. Protein Sci 14:2693–2701
Muschol M, Rosenberger F (1997) Liquid-liquid phase separation in supersaturated lysozyme solutions and associated precipitate formation/crystallization. J Chem Phys 107:1953–1962
Ranke J, Mölter K, Stock F, Bottin-Weber U, Poczobutt J, Hoffmann J, Ondruschka B, Filser J, Jastorffa B (2004) Biological effects of imidazolium ionic liquids with varying chain lengths in acute Vibrio fischeri and WST-1 cell viability assays. Ecotoxicol Environ Safety 58:396–404
Schmidt S, Havekost D, Kaiser K, Kauling J, Henzler H-J (2004) Kristallisation für die Aufarbeitung von Proteinen. Chem Ing Tech 76:819–822
Seddon KR (1997) Ionic liquids for clean technology. J Chem Technol Biotechnol 68:351–356
Song CE (2004) Enantioselective chemo- and bio-catalysis in ionic liquids. Chem Commun:1033–1043
Summers CA, Flowers RA (2000) Protein renaturation by the liquid organic salt ethylammonium nitrate. Protein Scie 9:2001–2008
Swatloski RP, Holbrey JD, Memon SB, Caldwell GA, Caldwell KA, Rogers RD (2004) Using Caenorhabditis elegans to probe toxicity of 1-alkyl-3-methylimidazolium chloride based ionic liquids. Chem Commun: 668–669
Wasserscheid P, Welton T (eds) (2002) Ionic liquids in synthesis. Wiley/VCH, Weinheim
Yang Z, Pan W (2005) Ionic liquids: green solvents for nonaqueous biocatalysis. Enzyme Microbial Technol 37:19–28
Znamenskiy V, Kobrak MN (2004) Molecular dynamics study of polarity in room-temperature ionic liquids. J Phys Chem B 108:1072–1079
Acknowledgements
The authors thank Lorenz Chatwell and Arne Skerra for valuable advices in the initial phase of the work. The authors also acknowledge the experimental contribution of Hannes Schmid.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Hekmat, D., Hebel, D., Joswig, S. et al. Advanced protein crystallization using water-soluble ionic liquids as crystallization additives . Biotechnol Lett 29, 1703–1711 (2007). https://doi.org/10.1007/s10529-007-9456-9
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10529-007-9456-9