1. Thayer School of Engineering, Dartmouth College, 8000 Cummings, Hanover NH 03755, USA.
2. Monsanto Protein Technologies, 8520 University Green, Post Office Box 620999, Middleton, WI 53562-0999, USA.
3. Polytechnic University, National Science Foundation Center for Biocatalysis and Bioprocessing of Macromolecules, Six Metrotech Center, Brooklyn, NY 11201, USA.