RECOMBINANT FULL-LENGTH MURINE PRION PROTEIN, MPRP(23-231) - PURIFICATION AND SPECTROSCOPIC CHARACTERIZATION

The cellular prion protein of the mouse, mPrP(C), consists of 208 amin o acids (residues 23-231), It contains a carboxy-terminal domain, mPrP (121-231), which represents an autonomous folding unit with three alph a-helices and a two-stranded antiparallel beta-sheet, We expressed the complete amino acid sequence of the prion protein, mPrP(23-231), in t he cytoplasm of Escherichia coli, mPrP(23-231) was solubilized from in clusion bodies by 8 M urea, oxidatively refolded and purified to homog eneity by conventional chromatographic techniques, Comparison of near- UV circular dichroism, fluorescence and one-dimensional H-1-NMR spectr a of mPrP(23-231) and mPrP(121-231) shows that the amino-terminal segm ent 23-120, which includes the five characteristic octapeptide repeats , does not contribute measurably to the manifestation of three-dimensi onal structure as detected by these techniques, indicating that the re sidues 121-231 might be the only polypeptide segment of PrPC with a de fined three-dimensional structure. (C) 1997 Federation of European Bio chemical Societies.