The present invention relates to novel methods for generating variant
proteins with increased host string content by comparing a parent protein
sequence with two or more natural protein sequences from a host species,
analyzing one or more amino acid strings of the parent protein sequence
with a structurally corresponding amino acid string of each of said
natural protein sequences, substituting one or more amino acid strings of
the parent protein sequence with a structurally corresponding amino acid
string of one of the two or more natural protein sequences on an amino
acid string by amino acid string basis so that the variant protein has
increased host string content, and, synthesizing and screening the
variant protein.