Biological and chemocatalytic processes are tailored in order to maximize the production of sustainable biodiesel from lignocellulosic sugar. Thus, the combination of hydrotalcite-supported copper(II) and palladium(0) catalysts with a modification of the fermentation from acetone–butanol–ethanol to isopropanol–butanol–ethanol predictably produces higher concentrations of diesel-range components in the alkylation reaction.

An enticing possibility in nanotechnology is to use proteins as templates for the positioning of molecules in regular patterns with nanometer precision over large surface areas. However, the ability to redesign protein quaternary structure to construct new shapes remains underdeveloped. In the present work, we have engineered the dimensions of a filamentous protein, the γ prefoldin (γ PFD) from the hyperthermophile Methanocaldococcus jannaschii, and have achieved controllable attachment of filaments in a specific orientation on a carbon surface. Four different constructs of γ PFD were generated in which the coiled coils extending from the association domain are progressively truncated. Three of the truncation constructs form well-defined filaments with predictable dimensions according to transmission electron microscopy. Two of these constructs had 2D persistence lengths similar to that of γ PFD at 300–740 nm. In contrast, the 2D persistence length of the shortest truncation mutant was 3500 nm, indicating that the filament adsorbs along a different axis than the other constructs with its two rows of coiled coils facing out from the surface. The elastic moduli of the filaments range from 0.7–2.1 GPa, similar to rigid plastics and within the lower limit for proteins whose primary intermolecular interaction is hydrogen bonding. These results demonstrate a versatile approach for controlling the overall dimensions and surface orientation of protein filaments, and expand the toolbox by which to tune two overall dimensions in protein space for the creation of templated materials over a wide variety of conditions. © 2009 Wiley Periodicals, Inc. Biopolymers 91: 496–503, 2009.

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