A single processive and tightly-coupled molecular motor such as kinesin performs mechanical work by using the heat absorbed by the motor from the surroundings upon catalyzing spontaneously occurring ATP hydrolysis. This is a conclusion derived from a thermodynamic analysis of the mechano-chemical cycle of such single molecular motors together with an equation that relates work done by single molecular motors to the thermodynamics of ATP hydrolysis catalyzed by the motors. Analysis of motor models based on the thermodynamic approach leads to a general equation depicting the stepping motion of such molecular motors as a biased random walk.
"Abduction" as formulated by C. S. Peirce, rather than deduction or induction, serves as an apt logical model for the practice of proteomics. Abduction has strength in application toward complex systems because by its nature it requires no presupposition. Our effort in the past twenty years to elucidate the protein phosphorylation cascade that is triggered by light stimulus in the photoreceptor cells of Drosophila is characterized by "proteomics approach without appropriate techniques available." Future proteomics should enable us not only to identify target proteins, but also to quantify their amounts, revealing the dynamic aspects of protein expression and function.
To elucidate neuronal mechanisms of acquisition of learning and retention of memory, studies of morphological modification at synapse have recently been attracting attention. In this review the dynamical features of physiological and morphological changes have been discussed in terms of the conditioning mechanisms observed in the sensory receptor cells in Hermissenda crassicornis.
The solid-state structures of Bombyx mori silk fibroin before and after spinning were determined with several solid-state NMR. A repeated β-turn type II structure was proposed for the former model and a heterogeneous structure which consists of two kinds of β-sheet structure with different inter-chain arrangement and distorted β-turn for the latter. New silk-like materials with several repeated sequences selected from B. mori and Samia cynthia ricini silk fibroins, and spider dragline silk were designed and produced using genetic engineering methods. The silk-like materials containing the cell-adhesive sequence, Arg-Gly-Asp, from fibronectin were produced similarly and their high cell-adhesive abilities were observed.