Abstract
Dermal fibroblasts in culture from a woman with a mild to moderate form of osteogenesis imperfecta synthesize two species of the proα2-chain of type I procollagen. One chain is normal. The abnormal chain has a slightly faster mobility than normal during electrophoresis in sodium dodecyl sulfate polyacrylamide gels. Analysis of cyanogen bromide peptides of the proα-chain, the α-chain, and of the mammalian collagenase cleavage products of the proα- and α-chains indicates that the abnormality is confined to the α2(I)CB4 fragment and is consistent with loss of a short triple-helical segment. Type I collagen production was decreased, perhaps because the molecules that contained the abnormal chain were unstable, with a resultant alteration in the ratio of type III to type I collagen secreted into culture medium. Collagen fibrils in bone and skin had a normal periodicity but their diameters were 50% of control; the bone matrix was undermineralized. The structural abnormality in the α2(I)-chain in this patient may affect molecular stability, intermolecular interactions, and collagen-mineral relationships that act to decrease the collagen content of tissues and affect the mineralization of bone.
Original language | English (US) |
---|---|
Pages (from-to) | 689-697 |
Number of pages | 9 |
Journal | Unknown Journal |
Volume | 71 |
Issue number | 3 |
DOIs | |
State | Published - 1983 |
Externally published | Yes |
ASJC Scopus subject areas
- General Medicine