Origin of the stability conferred upon collagen by fluorination.

ABSTRACT: According to a prevailing theory, (2S,4R)-4-hydroxyproline (Hyp) residues stabilize the collagen triple helix via a stereoelectronic effect that preorganizes appropriate backbone torsion angles for triple-helix formation. This theory is consistent with the marked stability that results from replacing the hydroxyl group with the more electron-withdrawing fluoro group, as in (2S,4R)-4-fluoroproline (Flp). Nonetheless, the hyperstability of triple helices containing Flp has been attributed by others to the hydrophobic effect rather than a stereoelectronic effect. We tested this hypothesis by replacing Hyp with 4,4-difluoroproline (Dfp) in collagen-related peptides. Dfp retains the hydrophobicity of Flp, but lacks the ability of Flp to preorganize backbone torsion angles. Unlike Flp, Dfp does

SUBMITTER: Shoulders MD 

PROVIDER: S-EPMC2709698 | biostudies-literature | 2009 Jul

REPOSITORIES: biostudies-literature