Modifying the properties of enzymes and proteins has become a relatively routine practice in both the academic and the bioindustrial sectors since the first introduction of the concept in the late 70's to early 80s. The original tools of sitespecific modification and three dimensional structural analysis based design have expanded to include regio-targeted mutagenesis, homology based recnlitment of amino acid residues and in vivo and in vitro recombination of genes. The advent of PCR based methodologies for gene cloning and manipulation have