Partial nucleotide sequence of the parvalbumin from chicken thymus designated "avian thymic hormone"

The incomplete amino acid sequence of the protein identified as avian thymic hormone was recently reported [Brewer et al. (1989), Biochem. Biophys. Res. Commun. 160, 11555-1161], and a very high degree of homology to the parvalbumins was apparent. Using mixed oligonucleotide primers based on the reported protein sequence, we have succeeded in amplifying and cloning a 188 bp fragment of the coding region for this protein, beginning with double-stranded cDNA prepared from chicken thymus mRNA. The translated nucleotide sequence of this fragment and the reported amino acid sequence display substantial disagreement. Most notably, the nucleotide sequence indicates that the CD site of avian thymic hormone is a typical parvalbumin CD site.