Further biochemical and physicochemical characterization of minor disulfide-bonded (type IX) collagen, extracted from foetal calf cartilage
✍ Scribed by Sylvie Ricard-Blum; Jérôme Tiollier; Robert Garrone; Daniel Herbage
- Publisher
- John Wiley and Sons
- Year
- 1985
- Tongue
- English
- Weight
- 869 KB
- Volume
- 27
- Category
- Article
- ISSN
- 0730-2312
No coin nor oath required. For personal study only.
✦ Synopsis
Minor disulfide-bonded collagen (previously termed XI -X7 and now called type IX collagen) was isolated from foetal calf cartilage after pepsin treatment. At least three native fractions, containing, respectively, the xlx2x3, &, and xsx6x7 chains, were separated; and from further biochemical and physicochemical experiments (differential scanning calorimetry, electrical birefringence, rotary shadowing), we propose a tentative model for their organization within a parent molecule. XI and X2 are molecules composed of three chains of apparent M, 62,000 and 50,000 linked by interchain disulfide bonds and containing pepsin-sensitive regions. The cleavage of at least three of these sites, present within Xz, gives rise to the X3 and XsX6X7 fractions composed of molecules 80-100 nm and 40-55 nm in length, respectively. The xsx6x7 fraction is not digested by pepsin at 30°C owing to its high thermal stability (certainly explained by its high hydroxyproline + proline content). This organization is in good accordance with that proposed for chicken cartilage type IX collagen; differences could only exist in the number and (or) the location of the pepsin-sensitive sites.