Interactions between collagen IX and biglycan measured by atomic force microscopy.
The stability of the lattice-like type II collagen architecture of articular cartilage is paramount to its optimal function. Such stability not only depends on the rigidity of collagen fibrils themselves, but more importantly, on their interconnections. One known interconnection is through type IX and biglycan molecules. However, the mechanical properties of this interaction and its role in the overall stability remain unrevealed. Using atomic force microscopy, this study directly measured the mechanical strength (or the rupture force) of a single bond between collagen IX and biglycan. The results demonstrated that the rupture force of this single bond was 15pN, which was significantly smaller than those of other known molecule interactions to date. This result suggested that type IX collagen and biglycan interaction may be the weak link in the cartilage collagen architecture, vulnerable to abnormal joint force and associated with disorders such as osteoarthritis.
Chen
Chia-Hsin
CH
Department of Orthopedic Surgery, Baylor College of Medicine, Houston, TX, USA.
Yeh
Ming-Long
ML
Geyer
Mark
M
Wang
Gwo-Jaw
GJ
Huang
Mao-Hsiung
MH
Heggeness
Michael H
MH
Höök
Magnus
M
Luo
Zong-Ping
ZP
D058578:Biglycan; D001696:Biomechanical Phenomena; D024081:Collagen Type IX / Q000737:chemistry*; D016326:Extracellular Matrix Proteins; D018625:Microscopy, Atomic Force; D011485:Protein Binding; D011509:Proteoglycans / Q000737:chemistry*
D058578:Biglycan; D024081:Collagen Type IX; D016326:Extracellular Matrix Proteins; D011509:Proteoglycans