The amino-acid sequence of the alpha-crystallin A chains of red kangaroo and Virginia opossum.

The amino acid sequence of the A chain of the eye lens protein alpha-crystallin from the red kangaroo (Macropus rufus) was completely determined by manual Edman degradation of tryptic, thermolytic and cyanogen bromide peptides. The sequence of the alpha-crystallin A chain from the Virginia opossum (Didelphis marsupialis) was deduced from amino acid analyses and partial Edman degradation of peptides. The 173-residue A chains of kangaroo and opossum differ in six positions, whereas comparison with the bovine alpha-crystallin A chain reveals 17 and 22 substitutions, respectively. Most substitutions occur in the COOH-terminal part of the chain.