Interruption of a 3(10)-helix by a single Gly residue in a poly-Aib motif: a crystallographic study.
The structural influence of a single Gly residue inserted into an Aib(16) homooligomer was studied in the solid state by X-ray crystallography. The peptides N(3)Aib(8)GlyAib(8)PheNH(2) (1) and CbzPheAib(8)GlyAib(8) (2) were found to adopt well-defined helical structures, which are broadly 3(10) helical. Indeed, 2 is the longest crystallographic 3(10) helix thus far reported. However, in the region of the central Gly residue, a loosening of the 3(10) structure is observed in both peptides, with 1 clearly showing local adoption of an α-helical structure in the region of residues 7-9.
Solà
Jordi
J
School of Chemistry, University of Manchester, Manchester M13 9PL, UK.
Helliwell
Madeleine
M
Clayden
Jonathan
J
D020816:Amino Acid Motifs; D018360:Crystallography, X-Ray; D005998:Glycine / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D017433:Protein Structure, Secondary
D010455:Peptides; D005998:Glycine