Insolubility protein-based biological

In particular, in this chapter we examine a number of protein-based biological systems that can present excesses of insolubility or solubility. Some of these, for example, muscle contraction and hemoglobin transport of oxygen. 

As is argued in Chapter 8, small, often reversible, energy excursions back and forth across the boundary between associated (water-insoluble) and dissociated (water-soluble) oil-like domains (clusters of oil-like groups) drive the protein-based machines of biology. Biology often achieves mobility by many linear motors comprised of protein, such... 

A protein-based machine without water as an integral part of its structure could not function by the consilient mechanism. In other words, water is required in at least one of the two states in order to have a movable cusp of insolubility, and in order for competition for hydration to be relevant there must be adequate water present. The first prerequisite, therefore, in addressing the biological relevance of the consilient mechanism is to assess whether or not water exists within or between the changing structural elements of a protein motor during function. 

Fibrinogen is a fibrous protein that was first classified with keratin, myosin, and epidermin based on its 5.1 A repeat in wide-angle X-ray diffraction patterns (Bailey et al., 1943), which was later discovered to be associated with the Q-helical coiled-coil structure. It is a glycoprotein normally present in human blood plasma at a concentration of about 2.5 g/L and is essential for hemostasis, wound healing, inflammation, angiogenesis, and other biological functions. It is a soluble macromolecule, but forms a clot or insoluble gel on conversion to fibrin by the action of the... 

The high selectivity of affinity chromatography is based on biospecific interactions, such as those occurring between two molecules in natural biological processes. One interaction partner (ligand) is covalently attached (immobilization) to an insoluble carrier, while the corresponding partner (frequently a protein) is reversibly adsorbed by the ligand because of its complementary biospecific properties. 

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