Glycosylation/Hydroxylation-induced stabilization of the collagen triple helix. 4-trans-hydroxyproline in the Xaa position can stabilize the triple helix.
We have shown recently that glycosylation of threonine in the peptide Ac-(Gly-Pro-Thr)(10)-NH(2) with beta-d-galactose induces the formation of a collagen triple helix, whereas the nonglycosylated peptide does not. In this report, we present evidence that a collagen triple helix can also be formed in the Ac-(Gly-Pro-Thr)(10)-NH(2) peptide, if the proline (Pro) in the Xaa position is replaced with 4-trans-hydroxyproline (Hyp). Furthermore, replacement of Pro with Hyp in the sequence Ac-(Gly-Pro-Thr(beta-d-Gal))(10)-NH(2) increases the T(m) of the triple helix by 15.7 degrees C. It is generally believed that Hyp in the Xaa position destabilizes the triple helix because (Pro-Pro-Gly)(10) and (Pro-Hyp-Gly)(10) form stable triple helices but the peptide (Hyp-Pro-Gly)(10) does not. Our data suggest that the destabilizing effect of Hyp relative to Pro in the Xaa position is only true in the case of (Hyp-Pro-Gly)(10). Increasing concentrations of galactose in the solvent stabilize the triple helix of Ac-(Gly-Hyp-Thr)(10)-NH(2) but to a much lesser extent than that achieved by covalently linked galactose. The data explain some of the forces governing the stability of the annelid/vestimentiferan cuticle collagens.
Bann
J G
JG
Department of Biochemistry and Molecular Biology, Oregon Health Sciences University and Shriners Hospital for Children, Portland, Oregon 97201, USA.
Bächinger
H P
HP
D000595:Amino Acid Sequence; D000818:Animals; D002942:Circular Dichroism; D003094:Collagen / Q000737:chemistry*; D006031:Glycosylation; D006358:Hot Temperature; D006900:Hydroxylation; D006909:Hydroxyproline; D008969:Molecular Sequence Data; D009835:Oligochaeta; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000737:chemistry*; D011392:Proline; D020836:Protein Structure, Quaternary; D017433:Protein Structure, Secondary; D013816:Thermodynamics; D013912:Threonine
D010446:Peptide Fragments; D013912:Threonine; D003094:Collagen; D011392:Proline; D006909:Hydroxyproline