A
preprohormone is the
precursor protein to one or more
prohormones, which are in turn precursors to
peptide hormones. In general, the protein consists of the
amino acid chain that is created by the
hormone-secreting
cell, before any changes have been made to it. It contains a
signal peptide, the
hormone(s) itself (themselves), and intervening amino acids. Before the hormone is released from the cell, the signal peptide and other amino acids are removed.