Polymorphism in fowl serum albumin—I. Characterization of two genetic variants of fowl serum albumin and definition of peptide differences

1. 1. Two electrophoretically distinct serum albumin phenotypes, from highly inbred fowl, were isolated by high polymer fractionation and characterized physically and chemically. 2. 2. Each form contained alanine and aspartic acid as C-terminal and N-terminal amino acid residues respectively. There were no significant differences between the two in such physical parameters as sedimentation coefficient, diffusion coefficient, refractive index, viscosity or optical rotatory dispersion. 3. 3. The primary structures were studied by tryptic hydrolysis followed by peptide isolation by Sephadex G-10 gel filtration, two-dimensional finger-printing and paper electrophoresis. The structural difference between the two variants was identified as a lysine-neutral amino acid substitution by amino acid analyses of the isolated peptides.