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 WebApr 19, 2024 · The PDB structure of the Trp cage indicates that residues 2 to 8 form an α-helix, residues 11 to 14 comprise a 3 10 helix, whereas residues 15 to 20 adopt a polyproline II structure . The Trp cage is stabilized by a hydrophobic core in which tyrosine and proline surround a Trp residue and a salt bridge is present between Asp9 and Arg16.
PolyprOnline: polyproline helix II and secondary structure …
WebThe current theoretical work and additional experimental evidence show that, in short proline-rich peptides, alanine decreases the polyproline II helix content. In particular, the … WebApr 23, 2015 · With the aim of developing polyproline type II helix (PPII) secondary-structure mimetics for the modulation of prolin-rich-mediated protein–protein interactions, the … optio home health denver
Host−Guest Study of Left-Handed Polyproline II Helix Formation
WebJun 26, 2013 · The poly-l-proline type II (PPII) helix in recent years has emerged clearly as a structural class not only of fibrillar proteins (in collagen, PPII is a dominant conformation) … 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 … WebThe polyproline type II helical bundle fold of the 9.6-kDa springtail (Collembola) AFP from Granisotoma rainieri (a primitive arthropod) … optio investment partners