(03411) An Engineered PrPsc-like Molecule from the Chimera of Mammalian Prion Protein and Yeast Ure2p Prion-inducing Domain

Shao-Man YIN, Man-Sun
SY¹, and Po TIEN^*
( Institute of Microbiology, the Chinese Academy of Sciences, Beijing 100080,
China;
¹Institute of Pathology, Case Western Reserve University, Cleveland 44106, USA
)

Abstract Production of the
pathogenic prion isoform PrP^sc-like molecules is thought to be useful
for understanding the mysterious mechanism of conformational conversion process
of prion diseases and proving the “protein-only” hypothesis. In this
report, an engineered PrP^sc-like conformation was produced from a
chimera of mammalian bovine prion protein (bPrP) and yeast Ure2p prion-inducing
domain (UPrD). Compared with the normal form of bPrP, the engineered recombinant
protein, termed bPrP-UPrD, spontaneously aggregated into ordered fibrils under
physiological condition, displaying amyloid-like characteristics, such as fibrillar
morphology, birefringence upon binding to Congo red and increased fluorescence
intensity with Thioflavine T. Limited resistance to protease K digestion and
CD spectroscopy experiments suggested that the structure of bPrP-UPrD had been
changed, and adopted a new, high content β-sheet conformation during the fibrils
formation. Moreover, bPrP-UPrD amyloid fibrils could recruit more soluble forms
into the aggregates. Therefore, the engineered molecules could mimic significant
behaviors of PrP^sc and will be helpful for further understanding
the mechanism of conformational conversion process.

Key words yeast Ure2p prion-inducing
domain; PrP^sc-like molecule; conformational conversion

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Received: October 20, 2003 Accepted:
December 8, 2003
This work was supported by the grants from China National Frontier Research
Program (No. G1999075602) and the National Natural Foundation of China (No.
30270307)
*Corresponding author: Tel/Fax, 86-10-62554247; E-mail,
[email protected]