Collagen of fibrocartilage: a distinctive molecular phenotype in bovine meniscus

Abstract

Fibrocartilage of bovine knee meniscus was analyzed for major and minor collagen constituents. The main fraction (∼98%) of pepsin-solubilized collagen consisted of type I with a small proportion (< 10%) of type III molecules. The minor fraction (1–2%) isolated by salt precipitation could be further resolved into type V collagen that consisted of α1(V) and α2(V) chains and a type II-like molecule with chains that had all the characteristics of the 3α variant of α1(II) found in hyaline cartilage. The articular surface zone of the meniscus appeared 2–3-fold enriched in these minor collagens compared with deeper tissue, though qualitatively the same distinctive collagen phenotype was evident throughout.