Unveiling the role of histidine and tyrosine residues on the conformation of the avian prion hexarepeat domain(440 views) Pietropaolo A, Muccioli L, Zannoni C, La Mendola D, Maccarrone G, Pappalardo G, Rizzarelli E
Keywords: Histidine (his), Prion Protein (prp), Tyrosine Residues, Amino Acids, Animal, Article, Bird, Chemical Structure, Chemistry, Circular Dichroism, Computer Simulation, Protein Tertiary Structure, Stereoisomerism, Models, Molecular, Protein Structure, Protons,
Affiliations: *** IBB - CNR ***
Dipartimento di Chimica Fisica e Inorganica and INSTM, Universita di Bologna, Viale Risorgimento 4, 40136 Bologna, Italy.
CNR-Istituto di Biostrutture e Bioimmagini Catania, Viale Andrea Doria 6, 95125 Catania, Italy
Dipartimento di Scienze Chimiche, Università di Catania, Viale Andrea Doria 6, 95125 Catania, Italy
References: Not available.
Unveiling the role of histidine and tyrosine residues on the conformation of the avian prion hexarepeat domain
The prion protein (PrPC) is a glycoprotein that in mammals, differently from avians, can lead to prion diseases, by misfolding into a beta-sheet-rich pathogenic isoform (PrPSc). Mammal and avian proteins show different N-terminal tandem repeats: PHGGGWGQ and PHNPGY, both containing histidine, whereas tyrosine is included only in the primary sequence of the avian protein. Here, by means of potentiometric, circular dichroism (CD), and molecular dynamics (MD) studies at different pH values, we have investigated the conformation of the avian tetrahexarepeat (PHNPGY)4 (TetraHexaPY) with both N- and C-termini blocked by acetylation and amidation, respectively. We have found, also with the help of a recently proposed protein chirality indicator (Pietropaolo, A.; Muccioli, L.; Berardi, R.; Zannoni, C. Proteins 2008, 70, 667-677), a conformational dependence on the protonation states of histidine and tyrosine residues: the turn formation is pH driven, and at physiological pH a pivotal role is played by the tyrosine OH groups which give rise to a very compact bent structure of backbone upon forming a hydrogen-bond network.
Unveiling the role of histidine and tyrosine residues on the conformation of the avian prion hexarepeat domain
Kállay C, Dávid A, Timári S, Nagy EM, Sanna D, Garribba E, Micera G, De Bona P, Pappalardo G, Rizzarelli E, Sóvágó I * Copper(II) complexes of rat amylin fragments(517 views) Dalton T (ISSN: 1477-9234, 1477-9226, 1477-9234electronic), 2011 Oct 14; 40(38): 9711-9721. Impact Factor:3.838 ViewExport to BibTeXExport to EndNote