Low molecular weight urinary proteins. I. Partial amino acid sequences of the retinol-binding proteins of man and dog.

Human and dog retinol-binding proteins were isolated and their physico-chemical characteristics compared. Partial amino acid sequences of the first 50 residues were determined for both proteins and found to be remarkably similar. Only five residues were shown to be different; all could be due to single base pair mutations. However, immunological cross-reactivity was not detected between the two proteins with specific antisera prepared in rabbits against the human and dog retinol-binding proteins.