Absence of a specific copper(II) binding site in dog albumin is due to amino acid mutation in position 3

The elucidation of the primary sequence at the NH₂-terminal of dog serum albumin was undertaken by the dansyl-Edman technique on the intact protein molecule. This study was initiated because dog albumin failed to exhibit the characteristic albumin specificity for Cu(II) binding. The results show that a mutation in the primary sequence has replaced the important histidine-3 residue, critical to the binding of Cu(II), by a tyrosine residue. The primary sequence of the first eight residues was shown to be: Glx-Ala-Tyr ( ? )Ser-Glx-Ile-Ala.