Collagen and non-collagenous proteins in different mineralization stages of human femur.
Mineralized tissues exhibit varying degrees of mineralization in different areas within the same bone. Using the technique of density gradient fractionation, bone powder from the diaphysis of human femur has been separated in different fractions corresponding to the degree of mineralization. Isolated bone fractions were analysed for their content in collagen and non-collagenous proteins. The results showed marked differences between compact and spongy bones, this latter containing higher proportions of little mineralized bone particles than the former (p less than 0.01). The ethylenediaminetetra-acetic acid (EDTA) extractability and the bone matrix size decreased relative to the decrease in specific gravity of bone particles. Among the matrix components of different fractions, sialoprotein consistently increased with the increase in specific gravity while proteoglycan decreased in reverse manner to the increase in collagen. However, in the most mineralized fraction (specific gravity: 2.33 g/cm3), the proteoglycan amount increased while collagen decreased. In conclusion, this study of bone maturation in human femur confirms the suitability of the technique of density gradient fractionation in the studies of bone matrix-mineral interactions. Apart from the fraction with the highest specific gravity, the analytical results obtained in fractions are similar to those observed in age-related bone changes, suggesting that the increase in mineralization degree of bone particles may be related to their age.
Mbuyi-Muamba
J M
JM
Arthritis and Metabolic Bone Disease Research Unit, University Hospital, Pellenberg, Belgium.
Dequeker
J
J
Gevers
G
G
D000375:Aging / Q000378:metabolism*; D001846:Bone Development; D001857:Bone Matrix / Q000032:analysis*; D002118:Calcium / Q000032:analysis; D003094:Collagen / Q000032:analysis*; D005269:Femur / Q000032:analysis*; D006801:Humans; D010758:Phosphorus / Q000032:analysis; D011509:Proteoglycans / Q000032:analysis*; D012795:Sialoglycoproteins / Q000032:analysis*
D011509:Proteoglycans; D012795:Sialoglycoproteins; D010758:Phosphorus; D003094:Collagen; D002118:Calcium