Unfolding of helical trans-β2,3-hybrid peptides with (α-β) nα composition, when executed by increasing solvent polarity or temperature, proceeded in a systematic manner with the turns unwinding sequentially; C-terminal region of these peptides were first to unwind and the process propagated towards N terminus with more and more β residues equilibrating from the gauche to the anti rotameric state across CαCβ. This is evidenced by clear change in their CβH signal splitting, 3 JCαH-CβH values, and sequential disappearance of i, i+2 NOEs. [ABSTRACT FROM AUTHOR]