Sequence of the murine alpha-lactalbumin-encoding cDNA: interspecies comparison of the coding frame and deduced pre-protein.

The structure of the mouse alpha-lactalbumin-encoding mRNA was deduced from sequence analysis of eight cDNA clones. The almost full-length mRNA of 732 nucleotides [poly(A) tail excluded] and the deduced pre-protein share 85% and 86% homology with their rat counterpart, respectively. Interspecies comparison of the pre-protein showed the occurrence of an extra amino acid (aa) in the signal peptide and of two mutations affecting two reported invariant aa residues at positions 44 and 107, which weakens the assumption that both aa residues might play a significant structural and/or functional role.