Proteins, chemical synthesis dynamics

The possibility of studying the structure and dynamic properties of proteins by F NMR requires the use of labeled proteins with fluorine. Various approaches can be envisioned trifluoroacetylation or derivatization of side chains by direct fluorination or trifluoromethylation or with small fluorinated molecules. It is also possible to incorporate a fluorinated amino acid into a protein, by using either a classical chemical synthesis or a biosynthetic approach. It is obvious that the chemical synthetic... 

One of the first stages of the chemicals effect on a cell consists in its link with a receptor. Then, the signal about this event may be transferred to other intracellular components in cytoplasm or nucleus. This, in its turn, causes changes in cell activity, namely its biosynthetic activity and the activities of individual enzymes, their complexes, and even whole organelles. In an intricate process of cell response to a signal, a key role belongs to bioprotein and the biosynthesis of its derivatives. Therefore, analysis of ES and IPG effect on mitotic activity and cell sizes of the regenerating liver as well as protein synthesis dynamics is of particular importance. 

In the body, the energy derived from food is released as body heat and also used in the synthesis of ATP. The energy captured in ATP is then transformed into other forms, i.e., chemical (synthesis of new compounds), mechanical (muscle contraction), electrical (nerve activity), electrochemical (various ion pumps), thermal (maintenance of body temperature), and informational (base sequences in nucleic acids, amino acids in proteins). In general, the energy of food provides for the specific dynamic action of food, the maintenance of the body s basal metabolism, and the energy expenditure associated with various types of activity. 

One particular asset of structured self-assemblies is their ability to create nano- to microsized domains, snch as cavities, that could be exploited for chemical synthesis and catalysis. Many kinds of organized self-assemblies have been proved to act as efficient nanoreactors, and several chapters of this book discnss some of them such as small discrete supramolecular vessels (Chapter Reactivity In Nanoscale Vessels, Supramolecular Reactivity), dendrimers (Chapter Supramolecular Dendrlmer Chemistry, Soft Matter), or protein cages and virus capsids (Chapter Viruses as Self-Assembled Templates, Self-Processes). In this chapter, we focus on larger and softer self-assembled structures such as micelles, vesicles, liquid crystals (LCs), or gels, which are made of surfactants, block copolymers, or amphiphilic peptides. In addition, only the systems that present a high kinetic lability (i.e., dynamic) of their aggregated building blocks are considered more static objects such as most of polymersomes and molecularly imprinted polymers are discussed elsewhere (Chapters Assembly of Block Copolymers and Molecularly Imprinted Polymers, Soft Matter, respectively). Finally, for each of these dynamic systems, we describe their functional properties with respect to their potential for the promotion and catalysis of molecular and biomolecu-lar transformations, polymerization, self-replication, metal colloid formation, and mineralization processes. 

As an alternative approach to solution-state NMR methods, which are ineffective with lipid bilayer samples, solid-state NMR methods have been refined sufficiently to permit structural details to be obtained for membrane-embedded peptides and proteins. This usually requires isotopic enrichment, either through chemical synthesis or biosynthetic incorporation in expressed peptides and proteins. In the absence of routine X-ray crystallographic structural studies for these molecules, solid-state NMR spectroscopy has the potential to be a powerful and unique approach to determining the structures and describing the dynamics and functions of membranes and membrane-bound proteins. In addition, solid-state NMR spectroscopy has been widely used to describe lipid structure, dynamics and phase properties. Thus, solid-state NMR experiments can be... 

In this chapter we first describe the composition of cellular membranes and their chemical architecture— the molecular structures that underlie their biological functions. Next, we consider the remarkable dynamic features of membranes, in which lipids and proteins move relative to each other. Cell adhesion, endocytosis, and the membrane fusion accompanying neurotransmitter secretion illustrate the dynamic role of membrane proteins. We then turn to the protein-mediated passage of solutes across membranes via transporters and ion channels. In later chapters we discuss the role of membranes in signal transduction (Chapters 12 and 23), energy transduction (Chapter 19), lipid synthesis (Chapter 21), and protein synthesis (Chapter 27). 

Mechanistic studies of RNA enzymes (ribozymes) and ribonucleoprotein (RNP) complexes such as the ribosome and telomerase, often seek to characterize RNA structural features, either dynamic or static, and relate these properties to specific catalytic functions. Many experimental techniques that probe RNA structure-function relationships rely upon site-specific incorporation of chemically modified ribonucleotides into the RNA of interest, often in the form of chemical cross-linkers to probe for sites of protein-RNA interaction or small organic fluorophores to measure dynamic structural properties of RNAs. The ability to arbitrarily modify any RNA molecule has been greatly enabled by modern RNA synthesis techniques however, there remains a practical size... 

The dynamic process is akin to the error checking mechanisms employed in protein synthesis each reaction is reversible until the correct product has formed. In any evolutionary chemical system it is important to ensure copying fidelity and the success of dynamic combinatorial libraries indicates that concepts associate with supramolecular chemistry can be valuable in advancing chemical evolution. 

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