Claus Hélix-Nielsen

Accepted or rejected: the social life of biological electrolytes

 

Claus Hélix-Nielsen

 

CSO Aquaporin A/S & Associate Professor DTU Physics, Technical University of Denmark

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Biological membranes define the structural and functional building block of all known living organisms: the cell. The integrity of the cell depends on its ability to separate inside from outside and yet at the same time allow massive transport of matter in and out the cell. Nature has elegantly met this challenge by developing membranes in the form of lipid bilayers in which specialized and highly efficient transport proteins are incorporated. When the first cells emerged 3 to 4 billion years ago it was indeed the ability to shield precious components from the hostile surroundings that enabled the evolution of life.

This raises the question: is it possible to mimic biological membranes and create membrane based sensor and/or separation devices? We have addressed this issue by creating biomimetic membrane capable of supporting reconstituted membrane proteins. Such arrays have the potential of being platforms for biomedical applications. High-throughput screening systems based on membrane arrays may become an important alternative to cell-based screening of potential drug candidates on membrane protein targets. The transport properties of channel proteins or peptides may also be utilized in novel sensor based platforms such stochastic sensors for detection of organic molecules in solutions for use in medicine, or in separation applications based on ion/water selective channel proteins. In particular we have created biomimetic membranes using aquaporins, which are water selective protein channels, which among other functions, filter water in the mammalian kidney. We envision aquaporin-based large scale biomembranes as a new generation water purification system for medical use e.g. hemodialysis, or large scale industrial processes e.g. desalination.

However there are still fundamental scientific issues that need to be addressed in our understanding of protein-mediated water and solute transport. Here I will present some of these issues and discuss implications for biomimetic membrane development.

 

 

Nielsen, C. H. (2009). Lipid-protein interactions in biomembranes. In Handbook of Molecular Biophysics. H. G. Bohr, ed. Wiley, Berlin. 329-358.

 

Nielsen, C. H. (2009). Biomimetic membranes for sensor and separation applications. Anal Bioanal Chem 395:697-718.

 

Hansen, J. S., M. Perry, J. Vogel, J. Groth, T. Vissing, M. Larsen, O. Geschke, J. Emneus, H. Bohr, and C. H. Nielsen. (2009). Large scale biomimetic membrane arrays. Anal Bioanal Chem 395:719-727.

 

Gonzalez-Perez, A., K. B. Stibius, T. Vissing, C. H. Nielsen, and O. G. Mouritsen. (2009). Biomimetic Triblock Copolymer Membrane Arrays: A Stable Template for Functional Membrane Proteins. Langmuir 25:10447-10450.

 

Hansen, J. S., M. E. Perry, J. Vogel, T. Vissing, O. Geschke, J. Emneus, and C. H. Nielsen. (2009). Development of an automation technique for the establishment of functional lipid bilayer arrays. J. Micromech. Microeng. 19:025014.

 

Vogel, J., M. E. Perry, J. S. Hansen, P.-Y. Bollinger, C. H. Nielsen, and O. Geschke. (2009). Support structure for

biomimetic applications. J. Micromech. Microeng. 19:025026.

 

Nielsen, C. H. (2010). Osmotic Water Purification: Insights from Nanoscale Biomimetics. Environ Nano Technol. 1:58-65.

 

Ibragimova, S., K. B. Stibius, P. Szewczykowski, M. Perry, H. Bohr, and C. H. Nielsen. 2010. Hydrogels for in situ encapsulation of biomimetic membrane arrays. Polym. Adv. Technol. (in press).