Structural proteins, functions biological systems

Proteins are very important in biological systems as control and structural elements. Control fimctions of proteins are carried out by enzymes and proteinaceous hormones. Enzymes are chemicals that act as organic catalysts (a catalyst is a chemical that promotes but is not changed by a chemical reaction). Click here for an illustrated page about enzymes. Structural proteins function in the cell membrane, muscle tissue, etc. 

In this review by Franks et al. solid-state NMR shows its uses and applications in structural biology.Further developments promise great potential for investigations on functional biological systems such as membrane-integrated receptors and channels, and macromolecular complexes attached to cytoskeletal proteins. 

A central goal of science is to explain biological function at a molecular level, which therefore requires knowledge of the structure of the biological system. As genome research rapidly increases the number of proteins known, the requirement for obtaining structural information increases dramatically (7). 

These threaded CDs are supposed to play a supplementary role to control the structure of poly(8-VL) during polymerization. The CDs threaded by the poly(8-VL) prevented the polymer chain from entangling with itself or with another polymer chain so as to maintain the propagating state of the polyester. These processes are similar to those of chaperone proteins in biological systems that aid protein folding and allow the formation of functional proteins. CDs showed the activation and transformation of monomers analogous to enzymes and also protein-like refolding activity as artificial chaperones. ... 

Our work is targeted to biomolecular simulation applications, where the objective is to illuminate the structure and function of biological molecules (proteins, enzymes, etc) ranging in size from dozens of atoms to tens of thousands of atoms today, with the desire to increase this limit to millions of atoms in the near future. Such molecular dynamics (MD) simulations simply apply Newton s law to each atom in the system, with the force on each atom being determined by evaluating the gradient of the potential field at each atom s position. The potential includes contributions from bonding forces. 

From the atomic to the macroscopic level chirality is a characteristic feature of biological systems and plays an important role in the interplay of structure and function. Originating from small chiral precursors complex macromolecules such as proteins or DNA have developed during evolution. On a supramolecular level chirality is expressed in molecular organization, e.g. in the secondary and tertiary structure of proteins, in membranes, cells or tissues. On a macroscopic level, it appears in the chirality of our hands or in the asymmetric arrangement of our organs, or in the helicity of snail shells. Nature usually displays a preference for one sense of chirality over the other. This leads to specific interactions called chiral recognition. 

Table XI (346-390) lists a number of calcium-binding proteins and indicates very succinctly their role in biological systems. This table both illustrates the range of functions of calcium-binding proteins and serves to introduce those which appear subsequently in this chapter. The structures and functions of particularly important calcium-binding proteins such as calmodulin, parvalbumin, and troponin C are described in standard texts on biochemistry. The minimal Table XI entry for the particularly important calmodulins is amplified in the next paragraph. Table XI provides a sprinkling of references to enable readers to gain entry into the literature, for these and for most of the less-familiar species.

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