Multiple sequence alignment as a guideline for protein engineering strategies.

Many proteins lack the thermodynamic stability and/or solubility that is required for their use in a desired application. For this reason, it can be advantageous to improve these qualities through rational protein engineering. An effective means for achieving this goal is to use sequence alignment analysis to select amino acid substitutions that are likely to increase the thermodynamic stability or solubility of a protein. Advantages of using this approach are that generally only a small number of substitutions need to be tested, these substitutions are rarely debilitating to protein function, and knowledge of the three-dimensional structure of the protein of interest is not required. This chapter will describe approaches that have been used to exploit the information contained in sequence alignments for the engineering of improved protein properties.