1. The problem statement, all variables and given/known data A small octapeptide was isolated. Amino acid analysis from 6N HCl hydrolysis indicated: 14 micromoles alanine, 17 micromoles ammonium, 15 micromoles valine, 16 micromoles arginine, 46 micromoles of isoleucine, 15 micromoles of glycine, 17 micromoles of aspartate. Chemical treatment of the free carboxyl followed by 6N HCl hydrolysis yielded 2-amino-propanol. What does this say about the octapeptide? 2. Relevant equations At the moment, I can't think of any chemical equations for the listed part above. NH4+ is a direct measure of asparagine converted to aspartate and glutamine converted to glutamate. 3. The attempt at a solution In the aforementioned octapeptide, the only two free carboxyl groups that I can think of is the one at the C-terminal end and aspartate's R group, which is a carboxyl group. I am confused over the identity of the "chemical treatment" directed at the free carboxyl. Any help is appreciated. Thank you.