NR AJTU
AU Qin,K.; Yang,D.S.; Yang,Y.; Chishti,M.A.; Meng,L.J.; Kretzschmar,H.A.; Yip,C.M.; Fraser,P.E.; Westaway,D.
TI Copper(II)-induced conformational changes and protease resistance in recombinant and cellular PrP. Effect of protein age and deamidation.
QU The Journal of Biological Chemistry 2000 Jun 23; 275(25): 19121-31
PT journal article
AB While PrPc rearranges in the area of codons 104-113 to form PrPsc during prion infections, the events that initiate sporadic Creutzfeldt-Jakob disease are undefined. As Cu(II) is a putative ligand for PrPc and has been implicated in the pathogenesis of Creutzfeldt-Jakob disease and other neurodegenerative diseases, we investigated the structural effects of binding. Incubation of brain microsomes with Cu(II) generated approximately 30-kDa proteinase K-resistant PrP. Cu(II) had little effect on fresh recombinant PrP23-231, but aged protein characterized by conversion of Asn-107 to Asp decreased alpha-helical content by approximately 30%, increased beta-sheet content 100%, formed aggregates, and acquired proteinase K resistance in the presence of Cu(II). These transitions took place without need for acid pH, organic solvents, denaturants, or reducing agents. Since conversion of Asn to Asp proceeds by a spontaneous pathway involving deamidation, our data suggest that covalent variants of PrPc arising in this manner may, in concert with Cu(II), generate PrPsc-like species capable of initiating sporadic prion disease.
MH Amides/chemistry; Amino Acid Sequence; Animal; Brain/metabolism; Copper/*metabolism; Disulfides/chemistry; Endopeptidase K/*metabolism; Mice; Microsomes/metabolism; Prions/chemistry/*metabolism; Protein Conformation; Recombinant Proteins/chemistry/metabolism; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Support, Non-U.S. Gov't
AD Centre for Research in Neurodegenerative Diseases, Department of Medical Biophysics, Mass Spectrometry Laboratory, Modern Medicine Research Centre, Toronto, Ontario M 5S 3HS, Canada.
SP englisch
PO USA