Decorin modulates collagen matrix assembly and mineralization

Asporin competes with decorin for collagen binding, binds calcium and promotes osteoblast collagen mineralization.

The interactions of the ECM (extracellular matrix) protein asporin with ECM components have previously not been investigated. Here, we show that asporin binds collagen type I. This binding is inhibited by recombinant asporin fragment LRR (leucine-rich repeat) 10-12 and by full-length decorin, but not by biglycan. We demonstrate that the polyaspartate domain binds calcium and regulates hydroxyap...

Dynamics of bone extracellular matrix assembly and mineralization.

Modulation of collagen gel contraction by decorin.

The small dermatan sulphate protein decorin interacts via its core protein with fibrillar collagens, and its glycosaminoglycan chains were proposed to be capable of self-association. It was therefore of interest to study the role of decorin in the contraction of cell-populated collagen lattices. Stable transfection of dihydrofolate reductase-deficient CHO cells with decorin cDNA resulted in imp...

Molecular assembly, secretion, and matrix deposition of type VI collagen

Monoclonal antibodies reactive with the tissue form of type VI collagen were used to isolate the type VI collagen polypeptides from cultured fibroblasts and muscle cells. Two [35S]methionine-labeled polypeptides of 260 and 140 kD were found intracellularly, in the medium, and in the extracellular matrix of metabolically labeled cells. These polypeptides were disulfide cross-linked into very lar...

Multiphase intrafibrillar mineralization of collagen.

In the past, the two major biomineralization motifs, biosilicification and biocalcification, were considered as two discrete processes. However, there is increasing evidence of the existence of an inextricable relationship between biosilica and calcium-based biominerals. The recent discovery of a unique silica–chitin–aragonite biocomposite in one genus of demosponges (Verongida) introduces a no...