Structural proteins of intracisternal A-particles: possible repetitive sequences.

Peptide maps of tryptic digests of the structural proteins from inner shells of intracisternal A-particles have shown common peptides for all the proteins. The terminal amino group of the three different structural proteins was identified as arginine. The major protein revealed approximately half the number of peptides expected from the amino acid composition. Since evidence for a cross-link bond has not been found, the main structural protein may be a single polypeptide chain containing a total or partial duplication of sequence.