A polyproline helix is a type of protein secondary structure which occurs in proteins comprising repeating proline residues. A left-handed polyproline II helix (PPII, poly-Pro II) is formed when sequential residues all adopt (φ,ψ) backbone dihedral angles of roughly (-75°, 150°) and have trans isomers of their peptide … See more The PPII helix is defined by (φ,ψ) backbone dihedral angles of roughly (-75°, 150°) and trans isomers of the peptide bonds. The rotation angle Ω per residue of any polypeptide helix with trans isomers is given by the equation See more The poly-Pro I helix is much denser than the PPII helix due to the cis isomers of its peptide bonds. It is also rarer than the PPII conformation because the cis isomer is higher in energy … See more Traditionally, PPII has been considered to be relatively rigid and used as a "molecular ruler" in structural biology, e.g., to calibrate FRET efficiency measurements. However, subsequent … See more WebNov 4, 2014 · The first crystal structure of an oligoproline adopting an all-trans polyproline II (PPII) helix is presented. The high-resolution structure provides detailed insight into the dimensions and conformational properties of oligoprolines that are important for, e.g., their use as “molecular rulers” and “molecular scaffolds”. The structure also showed that the …
Recent advances on polyproline II SpringerLink
WebMay 15, 2004 · The peptide was modeled in each of 4 conformers: alpha-helix, antiparallel beta-strand, parallel beta-strand, and polyproline II helix (P (II)). Monte Carlo simulations in the canonical ensemble were performed at 300 K using the CHARMM 22 forcefield with TIP3P water. The simulations indicate that the solvation free energy of P (II) is favored ... WebJun 26, 2013 · The history of the discovery of the poly-l-proline type II (polyproline-II or PPII) helix is strikingly different from the two major structures of folded (globular) proteins, the … tasmania phone extension
A Unique and Stable Polyproline I Helix Sorted out from …
WebApr 4, 2024 · In the inactive or “closed” form of Src, the SH2 domain interacts with pTyr527, placing the SH3 domain in the correct position to interact with the polyproline type II helix of the kinase-SH2 linker region, preventing the conformational change in … WebMar 14, 2024 · Polyproline II (PPII) is a common conformation, comparable to α-helix and β-sheet. PPII, recently termed with a more generic name—κ-helix, adopts a left-handed structure with 3-fold rotational symmetry. WebMar 31, 2011 · PolyProline II (PPII) helix is yet another interesting repetitive structure which is less frequent and not usually associated with stabilizing ... Zagrovic B, Lipfert J, Sorin EJ, Millett IS, van Gunsteren WF, et al. (2005) Unusual compactness of a polyproline type II structure. Proc Natl Acad Sci U S A 102: 11698–11703. View ... tasmania phone book