Expression of a human serum albumin fragment (consisting of subdomains IA,IB, and IIA) and a study of its properties

Site-directed mutagenesis and a yeast expression system were used to synthe size a human serum albumin (HSA) fragment (amino acids 1-297), The HSA frag ment (half HSA) was evaluated with a number of biophysical techniques and f ound to be similar to the corresponding region in wild-type HSA, Specifical ly, the circular dichroism spectra of half HSA and wild-type HSA were super imposable, indicating that the highly cr-helical secondary structure of wil d-type HSA is preserved in half HSA, Additionally, half HSA was partially r eactive with a polyclonal antibody against authentic HSA, Half HSA, which c ontains subdomain IIA, had an affinity for thyroxine and several thyroxine analogs, similar to that observed previously for wild-type HSA, This study suggests that the production of recombinant HSA fragments will be useful fo r the study of HSA ligand interactions.