Biological macromolecule, solution conformation

Chen R.H., Tsaih M.L. 1998. Effect of temperature on the intrinsic viscosity and conformation of chitosans in dilute HCl solution. International Journal of Biological Macromolecules 23,135-141. 

It has long been recognized that NMR cross relaxation data can provide information on the solution conformation of biological macromolecules, mainly through the inverse sixth power dependence of the cross-relaxation rates on internuclear distance. Only recently with the advent of sophisticated two-dimensional acquisition techniques has it become possible to attempt the a-priori determination of the solution conformation... 

There have already appeared artides reviewing the progress achieved in the fields of intermolecular forces, methods of statistical mechanics, and the structures of gases, liqiuds, and their molecular mixtures, including the critical region. De Voe reviews the theory of the conformations of biological macromolecules in solution, and Yomosa that of charge transfer in the molecular compounds of biolo cal systems. 

Operating conditions with SC CO2 are considered benign, especially for processing macromolecules such as peptides, proteins, and nucleic acids. The conventional method of protein production lyophilization subjects macromolecules to freeze-thaw cycles, potentially affecting solution conformation and biological activity. " ... 

Although conformational control of synthetic macromolecules is a daunting proposition, given the enormous entropy cost that has to be borne, approaches to achieve this are being actively researched. Typically, synthetic polymer chains adopt a random coil conformation in solution, unlike biological macromolecules which... 

Biologically active materials, such as polypeptides and nucleic acids, are composed of many of these polar groups and many apolar residues. Not only are the conformations of the macromolecule influenced by the presence of water as the solvent, but the presence of these macromolecules is able to influence the solvents behaviors. Thus we might look at a system and decide if it could serve as an antifreeze or a good nucleating substrate by first obtaining an understanding of its solution conformations. 

As implied in the Introduction, both proteins and (deoxy)ribonucleic acids can be viewed as ideal tyligomers—that is, the archetypal biological examples of discrete, high molecular weight macromolecules of mixed sequences with compact solution conformations assembled from many subunits of secondary structure. In our assessment of the literature, we have organized foldamer systems into four... 

Further additives to the mobile phase involve the structure-breaking, solubilizing and dissociation promoting agents that prevent the excessive solute-solute interactions or ensure the appropriate and conformationally stable structure of biological macromolecules, e.g., random coil conformation. These additives are most often urea... 

What results, usually, is a family of closely similar structures, all of which are consistent with the NOESY data. Within the limits of experimental error, this family of structures represents the dynamic conformational population of the protein in solution, and quite often emphasizes the inherent flexibility of biological macromolecules (see Figure 2.39). 

Multinuclear NMR methods are used to study the conformation and dynamics of biological macromolecules in solution. 

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