Dentin extracellular matrix has been shown to contain components capable of inducing chondrogenesis and osteogenesis at ectopic sites when implanted in vivo, and chondrogenesis in cultures of embryonic muscle-derived fibroblasts (EMF) in vitro. The polypeptide responsible, called the chondrogenic-inducing agent (CIA), has been isolated from a 4.0-M guanidinium hydrochloride extract of demineralized bovine dentin matrix.
View Article and Find Full Text PDFPeritubular dentin (PTD) is a relatively dense mineralized tissue that surrounds the tubules of coronal tooth dentin. It is composed mainly of crystals of carbonated apatite together with a small amount of collagen. Its mode of formation has been investigated by studying the relatively dense particles isolated from a powdered preparation.
View Article and Find Full Text PDFJ Struct Biol
October 1998
It has been postulated that phosphophoryn (PP) molecules bind specifically to type I collagen fibrils as the key event in inducing matrix mineralization in dentin. The nature and specificity of the collagen molecule-PP interaction has been examined by rotary shadowing-electron microscopy of mixtures of native, monomeric lathyritic rat skin collagen and purified rat incisor PP. An antibody to the amino-telopeptide of the collagen alpha1(I)-chain was used to determine the N-terminal end of the collagen molecules.
View Article and Find Full Text PDFPhosphophoryns (PPs), a family of Asp and Ser(P)-rich dentin proteins, are considered to be archetypal regulators of several aspects of extracellular matrix (ECM) biomineralization. We have cloned a rat incisor PP gene, Dmp2, from our odontoblast cDNA library and localized it to mouse chromosome 5q21 within 2 centimorgans of Dmp1, another tooth-specific ECM protein. The carboxyl-terminal region of Dmp2 protein (60 residue % Ser, 31 residue % Asp) is divided into two domains, one with unique repetitive blocks of [DSS]n,3=14, the other with [SD]m = 2,3.
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