ABSTRACT

ABSTRACT Active streaming (AS) of liquid water is considered to generate and overcome pressure gradients, so as to drive cell motility and muscle contraction by hydraulic compression. This idea had led to reconstitution of cytoplasm streaming and muscle contraction by utilizing the actin-myosin ATPase system in conditions that exclude a continuous protein network. These reconstitution experiments had disproved a contractile protein mechanism and inspired a theoretical investigation of the AS hypothesis, as presented in this article. Here, a molecular quantitative model is constructed for a chemical reaction that might generate the elementary component of such AS within the pure water phase. Being guided by the laws of energy and momentum

conservation and by the physical chemistry of water, a vectorial electro-mechano-chemical conversion is considered, as follows: A ballistic H+ may be released from H2O-H

+ at a velocity of 10km/sec, carrying a kinetic energy of 0.5 proton*volt. By coherent exchange of microwave photons during 10-10 sec, the ballistic proton can induce cooperative precession of about 13300 electrically-polarized water molecule dimers, extending along 0.5 µm. The dynamic dimers rearrange along the proton path into a pile of non-radiating rings that compose a persistent rowing-like water soliton. During a lifetime of 20 msec, this soliton can generate and overcome a maximal pressure head of 1 kgwt/cm2 at a streaming velocity of 25 µm/sec and intrinsic power density of 5 Watt/cm3. In this view, the actin-myosin ATPase is proposed to catalyze stereo-specific cleavage of H2O-H

+, so as to generate unidirectional fluxes of ballistic protons and water solitons along each actin filament. Critical requirements and evidential predictions precipitate consistent implications to the physical chemistry of water, enzymatic hydrolysis and synthesis of ATP, trans-membrane signaling, intracellular transport, cell motility, intercellular interaction, and associated electro-physiological function. Sarcomere contraction is described as hydraulic compression, driven by the suction power of centrally-oriented AS. This hydraulic mechanism anticipates structural, biochemical, mechanical and energetic aspects of striated muscle contraction, leading to quantitative formulation of a hydrodynamic power-balance equation yielding a general force-velocity relation.