[1]Abderhalden;Koeppel[Fermentforschung,vol.9,p.441][ChemischesZentralblatt,1928,vol.99,#II,p.574]
[1]Smith;Bergmann[JournalofBiologicalChemistry,1944,vol.153,p.627,649]
[1]JournalofBiologicalChemistry,1954,vol.208,p.573,577
Title: The crystal structure of the collagen-like polypeptide (glycyl-4(R)-hydroxyprolyl-4(R)-hydroxyprolyl)9 at 1.55 A resolution shows up-puckering of the proline ring in the Xaa position.
Journal: The Journal of biological chemistry 20050527