Protein structure global stability

The structure of the ribosomal protein L9 from B. stearothermophilus is shown in Fig. 3. The folding kinetics and thermodynamics of its C-terminal domain have been studied as a function of pH by NMR and CD spectroscopies. The ionization state of the two histidines (Hisl06 and His 134) was found to be essential for the global stability and the folding rate of the protein. ... 

Above, we showed how a finely modulated balancing act between stabilizing and destabilizing forces yields marginally stable protein structures. We now examine in more detail how the same types of noncovalent interactions are used in differently thermally adapted proteins to achieve appropriate levels of structural stability. The adaptive changes discussed below are relevant to both global protein stability and to the establishment of the appropriate balance between stability and flexibility required for... 

The fact that the folding (and unfolding) kinetics of relatively small, two-state proteins can be predicted with reasonable accuracy from global features of the native state like the contact order, stability, and number of contacts supports the idea that the details of protein structure are not required to capture the key features of protein folding, so that reduced representations should be adequate. However, the most widely used simple heteropolymer models, those restricted to a simple cubic lattice, predict that stability is more important than native structure, in contrast to the experimental data for proteins. In this section we seek to understand why lattice models differ from proteins in this regard. Doing so is of importance because complete details of the folding trajectories of such models... 

One global property suitable for evaluation of evolutionary intermediates is protein stability. The unique biological and physical properties of an enzyme are highly dependent on the integrity of its native conformation. The structural stability of a protein can be measured by its resistance to heat, acid, and various chaotropic agents. Measurements of the thermostability of lysozymes provide an easy and an accurate way to assess the protein stability. 

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