Gustiananda, MarsiaHaris, Parvez IMilburn, Peter JGready, Jill2015-12-100014-5793http://hdl.handle.net/1885/65421We report the first Fourier transform infrared analysis of prion protein (PrP) repeats and the first study of PrP repeats of marsupial origin. Large changes in the secondary structure and an increase in hydrogen bonding within the peptide groups were evident from a red shift of the amide I band by >7 cm-1 and an approximately five-fold reduction in amide hydrogen-deuterium exchange for peptide interacting with Cu2+ ions. Changes in the tertiary structure upon copper binding were also evident from the appearance of a new band at 1564 cm-1, which arises from the ring vibration of histidine. The copper-induced conformational change is pH dependent, and occurs at pH >7.Keywords: amide; copper; copper ion; deuterium; histidine; hydrogen; prion protein; article; conformational transition; hydrogen bond; infrared spectroscopy; marsupial; pH; priority journal; protein interaction; protein structure; Animals; Copper; Opossums; Prions; Copper binding; Fourier transform infrared spectroscopy; Marsupial protein; Prion protein; Repeat peptide; Secondary structure200210.1016/S0014-5793(01)03298-72015-12-10