Fragment length influences affinity for Cu2+ and Ni2+ binding to His96 or His111 of the prion protein and spectroscopic evidence for a multiple histidine binding only at low pH.

ABSTRACT: The prion protein (PrP) is a Cu2+-binding cell-surface glycoprotein. Using various PrP fragments and spectroscopic techniques, we show that two Cu2+ ions bind to a region between residues 90 and 126. This region incorporates the neurotoxic portion of PrP, vital for prion propagation in transmissible spongiform encephalopathies. Pentapeptides PrP-(92-96) and PrP-(107-111) represent the minimum motif for Cu2+ binding to the PrP-(90-126) fragment. Consequently, we were surprised that the appearance of the visible CD spectra for two fragments of PrP, residues 90-126 and 91-115, are very different. We have shown that these differences do not arise from a change in the co-ordination geometry within the two fragments; rather, there is a change in the relative preference for the two binding sites

SUBMITTER: Klewpatinond M 

PROVIDER: S-EPMC1896292 | biostudies-literature | 2007 Jun

REPOSITORIES: biostudies-literature