Three families with fast bisalbuminaemia

We describe three cases of familial (SH, AY, and TM) fast-type bisalbuminaemia identified from 300 000 electrophoretic strips screened during the past six years. The immunological antigenicity and chemical composition of the isolated fast and normal albumins were essentially indistinguishable in all three cases. Detailed analyses on one of them (TM) by circular dichroism and fluorescent spectra measurements indicated that there was a marked change in the environment of the single tryptophan residue of the fast albumin, suggesting an alteration in the tertiary structure of the molecule. It is likely that this abnormality of the tertiary structure modulated (perturbed) the distribution of electric charges on the protein surface and thus changed its electrophoretic mobility.