Enzymes from extreme thermophylic bacteria

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 number of challenging problems regarding the physico-chemical molecular level are posed to biochemists and biophysicists, i.e. (1) the specificity of the protein intramolecular structure giving such high thermostability and resistance to outer effectors (2) the physical reasons for such poor catalytic activity at ambient temperature, 

Investigation of thermostable protein dynamics by indirect methods such as the kinetics of proteolysis and H-D exchange as well as buried chromophore fluorescence quenching, has led to the conclusion that at ambient temperature their globules are essentially less flexible than for non-thermostable proteins (Vetriani et al., 1998 and references therein). 

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