Protein intramolecular dynamics

Protein Intramolecular Dynamics and Catalytic Activity of Enzymes. 

Schwille P, Kummer S, Heikal AA, Moemer WE, Webb WW (2000) Fluorescence correlation spectroscopy reveals fast optical excitation-driven intramolecular dynamics of yellow fluorescent proteins. Proc Natl Acad Sci USA 97 151-156... 

At present, three main approaches to the analysis of intramolecular dynamics in proteins based on fluorescence studies are most commonly used (Figure 2.3).( 4)... 

K. K. Turoverov and I. M. Kuznetsova, Polarization of intrinsic fluorescence of proteins. 2. The studies of intramolecular dynamics of tryptophan residues, Mol. Biol. (Moscow) 17, 468-475 (1983). 

Data on the intramolecular dynamics of proteins obtained by the physical labeling approach combined with other dynamical and complementary theoretical and experimental methods may be briefly summarized as follows. 

In recent years, increasing attention has been focused on proteins derived from extreme thermophylic bacteria (Daniel and Cowan, 2000 Vetriani et al., 1998 Jaenicke, 1996 1998, 2000 Adams and Kelly, 2001 and references therein). The increasing use of these proteins in biotechnology has given new impetus to studies focused on their structure and stability. At the same time, thermostable proteins prove challenging as the ideal candidates for investigating the relationships between the structure and intramolecular dynamics of the enzyme on the one hand, and their function and stability on the other. 

A matrix, carrying the model catalysis active site, should provide unimpeded entrance to reagents and exit to products, and free room for conversion of each intermediate (the dynamic adaptation). In other words, the matrix should exhibit optimum molecular dynamicssimilar to intramolecular dynamics of proteins. 

As shown in this chapter, pressure effects on proteins are on intramolecular dynamics as well as on intramolecular and intermolecular interactions. Because the effects are less severe than temperature effects, there are good reasons to study pressure effects on biological macromolecules and compare them with temperature and chemical effects. 

Solid-state NMR spectroscopy is well suited for studies of intramolecular dynamics because side chain motions can be analyzed Independent of overall molecular reorientation in crystalline samples. It is an alternative spectroscopic strategy to solution NMR because partial motional averaging of the anisotropic spin interactions occurs. Dipolar, chemical shift, and quadrupolar interactions can be used to describe the dynamics of aromatic rings of proteins and peptides. 

Spin and fluorescent labelling experiments on intramolecular dynamics of hyperthermostable -glycosidase indicate a higher rigidity of the enzyme protein globule as compared with the relevant non-thermostable enzymes, as well as clear-cut correlation between conformational mobility and the catalytic activity of the enzyme active site at high temperature (90-100° C)... 

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