Characterisation of recombinant unglycosylated human serum transferrin purified from Saccharomyces cerevisiae

Structural identity between a recombinant transferrin mutant (N413Q, N611Q) secreted from Saccharomyces cerevisiae and the native protein was shown by CD analysis and immunodiffusion assays against anti-hSTf. The ability of the recombinant protein to bind iron was confirmed by urea-PAGE and EPR analysis of the iron-saturated protein revealed the characteristic holo-transferrin spectrum, indicating conservation of both iron-binding sites. The integrity of the unglycosylated recombinant protein indicates that such protein could be a valuable tool not only for structure-function characterisation but also crystallisation assays. In addition, the recombinant transferrin was found to be as effective as native transferrin as a growth factor in cell culture medium.