Motion model protein machines

Synthetic Model Protein Machines Emulate Energy Conversions of Photosynthesis, Respiration, and Motion... 

Polymers III through VI represent a systematic increase in the number of Val (V) residues replaced by more oil-like Phe (F) residues. Each step increase in oil-like character of the model protein, on going from 0 to 2 to 3 to 4 and to 5 Phe residues for every 30 residues, stepwise increases the affinity of Na for -COO . Each step increase in oil-like character means that less of an increase in salt is required to drive contraction. Polymer VI, when cross-linked into elastic sheets, provides the most efficient molecular machine of the set. This molecular machine requires less chemical energy to produce a given amount of motion, that is, to perform a given amount of mechanical work. 

At the time that this simple two-state mechanism was conceived—and, indeed, in most attempts to model unknown structures—the proteins were pictured as smooth and symmetrical. In keeping with this image, the motions associated with both regulation and contraction were pictured by many as being simple and machine-like (but see an alternative view in Squire, 1975). 

Now we explore a model of how molecular machines such as proteins can combine Brownian motion with binding and release processes to create directed... 

---