z Each peptide bond is engaged in formation of H￾bonds z Very compact structure – High density that restricts interaction with other molecules z Proteins – Rigid, long, narrow rod – 5-80% content z High stability z Proline – not compatible; interrupts, bending of the chain α-helixz Each peptide bond is engaged in formation of H￾bonds z Very compact structure – High density that restricts interaction with other molecules z Proteins – Rigid, long, narrow rod – 5-80% content z High stability z Proline – not compatible; interrupts, bending of the chain α-helix