Type X collagen isolated from the hypertrophic cartilage of embryonic chick tibiae contains both hydroxylysyl- and lysylpyridinoline cross-links.
Hypertrophic cartilage from the tibiotarsus of Day 20 chick embryonic tibiae was found to contain an unusually high concentration of lysylpyridinoline (LP), a nonreducible collagen cross-link normally found only in bone and dentin but not in cartilage. Since type X collagen is abundant in this cartilage, research was conducted to see if type X was the primary source of LP. The 45-kDa pepsin-resistant form of type X was purified by immunoaffinity chromatography. It contained a high concentration of the LP cross-link while type II contained primarily hydroxylysylpyridinoline (HP), the predominant cross-link in cartilage. This, to our knowledge is the first time that type X has been shown directly to form nonreducible cross-links and that a collagen other than type I has a high level of LP. Also, it is interesting that the HP and LP cross-links are found in a collagen that is degraded so rapidly. Possible explanations for these findings are discussed.
Orth
M W
MW
Department of Biochemistry, Rush Medical College, Rush Presbyterian-St. Luke's Medical Center, Chicago, IL 60612, USA.
Luchene
L J
LJ
Schmid
T M
TM
D000596:Amino Acids / Q000032:analysis*; D000818:Animals; D002356:Cartilage / Q000737:chemistry* / Q000196:embryology / Q000473:pathology*; D002642:Chick Embryo; D003094:Collagen / Q000737:chemistry* / Q000302:isolation & purification; D003432:Cross-Linking Reagents; D004591:Electrophoresis, Polyacrylamide Gel; D006901:Hydroxylysine / Q000032:analysis*; D006984:Hypertrophy; D008970:Molecular Weight; D010434:Pepsin A; D013977:Tibia
D000596:Amino Acids; D003432:Cross-Linking Reagents; D006901:Hydroxylysine; C036020:deoxypyridinoline; D003094:Collagen; D010434:Pepsin A