STABILITY OF TYPE-I COLLAGEN CNBR PEPTIDE TRIMERS

As indices of triple helix stability of type I collagen CNBr peptide h omotrimers, Delta G degrees for monomer-trimer transitions and melting temperatures were obtained from circular dichroism measurements at in creasing temperatures. The data were compared with the stability of th e parent native molecule. Peptides were found to have a lower stabilit y than the whole collagen molecule. The general implication is that th e coordinated water molecules play a key role in determining collagen triple helical stability and high cooperativity at melting. Other fact ors (monomer stability, ionic and hydrophobic factors, variations of c omposition, specific sequence) could also contribute towards peptide s tability; these factors could explain the data obtained in the case of peptide alpha 1(I) CB3. (C) 1997 Academic Press Limited.