Thermostability active-site mutation

Site-directed mutagenesis has been a valuable method for the engineering of many proteins, but a significant limitation on this technique is that it can be difficult to know what mutations should be made in order to obtain a desired functionality. For example, in order to increase the thermostability of a protein, it is not clear by looking at a 3-D structure which amino acid side chains will affect this trait. In addition, improvements made in the thermostability of the enzyme may adversely affect other properties of the protein, such as enzymatic activity. Therefore, there has been a good deal of interest in combinatorial methods for protein engineering, which can be used to sample a large area of the protein solution space, and thus rapidly identify proteins with desired functionalities. 

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