Naslov
NMR insights into early stages of structural conversion of human prion proteins related to inherited diseases

Autori
Ilc, Gregor ; Giachin, Gabriele ; Biljan, Ivana ; Legname, Giuseppe ; Plavec, Janez

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
5th International Conference on the Development of Biomedical Engineering / - , 2014, 42-42

Skup
5th International Conference on the Development of Biomedical Engineering

Mjesto i datum
Ho-Ši-Min, Vijetnam, 16.06.2014. - 18.06.2014

Vrsta sudjelovanja
Pozvano predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Prion protein; Prion diseases; Mutations; NMR structure

Sažetak
In human genetic forms of prion diseases, mutations in the globular C-terminal domain of PrPC are hypothesized to favor spontaneous generation of PrPSc in specific brain regions leading to neuronal cell degeneration and death. We hypothesize that high-resolution solution-state NMR structures on HuPrPs with pathological Q212P and V210I mutations linked to GSS and fCJD respectively, and HuPrP carrying naturally occurring E219K polymorphism considered to protect against sCJD might provide insights into the early stages of prion diseases. Nuclear Magnetic Resonance spectroscopy offers unique potential amongst the experimental methods to obtain topological assignment and detailed atomic-level structure information. The sequence-specific 1H, 13C and 15N backbone assignment was achieved to a very high degree, and it enabled protein structure determination of mutant PrP protein(s). Finally, 120 out of 141 (excluding C-terminus His tag) residues were successfully assigned, which corresponds to 85% of the HuPrP(90-231) sequence. The unassigned residues are located mostly around Phe175 and constitute a very flexible and hydrophilic fragment of HuPrP(90-231) structure. For those residues, the signals from NH protons are not observed in 1H-15N HSQC spectrum probably due to fast exchange with water. Moreover, this part of HuPrP(90-231) structure is involved in a pronounced chemical exchange process at the intermediate NMR timescale, which results in an additional increase of resonance linewidths. The NMR structure of the recombinant human PrP, HuPrP(90-231, M129, Q212P), believed to cause inherited GSS, provides new insights into the conformational preorganization and early stages of spontaneous conversion of PrPC into PrPSc. The secondary structure of the Q212P mutant consists of a flexible disordered tail (residues 90-124) and a globular domain (residues 125-231). The substitution of a proline at position 212 introduces unique structural differences in comparison to the known structures of either wild-type or other mammalian PrP, which are likely to have implications for understanding why and how changes in the native fold of endogenous PrPC lead to neurodegeneration or its degradation. Subtle local structural changes include an altered conformation of the β2-α2 loop along with loosening of tertiary contacts between the loop and the C-terminal end of helix α3, higher exposure of hydrophobic residues to solvent and perturbation of hydrophobic contacts at the α2-α3 inter-helical interface. In contrast to pathological mutants, hydrophobic interactions between residues from the β2-α2 loop and helix α3 are not interrupted in HuPrP with E219K polymorphismP

Izvorni jezik
Engleski

Znanstvena područja
Kemija

POVEZANOST RADA