ISSN:
1432-0827
Keywords:
Bone
;
Osteosarcoma
;
Matrix vesicles
;
Alkaline phosphatase
;
Aminopeptidase
;
Naphthylamidase
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
,
Physics
Notes:
Summary Extracellular matrix vesicles from bovine fetal alveolar bone and from a dog osteosarcoma were isolated by differential centrifugation and then fractionated on a discontinuous sucrose density gradient. The fractions were examined by electron microscopy and were analyzed for protein, alkaline phosphatase, aminotripeptidase, and four different β-naphthylamidase activities. The low-density peak of enzyme activities was shown by electron microscopy to be much more homogeneous than the crude matrix vesicle fraction. Two major peaks of protein and enzyme activities were present, one in the high and one in the low density layers. There was good correlation between the activities of alkaline phosphatase and the various peptidases in the fractions from the sucrose density gradient. These results indicate a coexistence of peptidase and alkaline phosphatase in matrix vesicles. On the other hand, there was generally no correlation between the peptidase and alkaline phosphatase activities in vesicular specimens from bovine liver obtained in the same way. Most of the peptidase activity and about half of the alkaline phosphatase activity were solubilized from bone matrix vesicles by detergents. The extracted alkaline phosphatase and alanyl β-naphthylamidase activities were separated from each other on a DEAE-cellulose column.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02405125
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