Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2007-7-9
pubmed:abstractText
Matrix vesicles (MVs) are involved in de novo mineral formation by nearly all vertebrate tissues. The driving force for MV mineralization is a nucleational core composed of three principal constituents: (i) amorphous calcium phosphate (ACP), complexed in part with phosphatidylserine (PS) to form (ii) calcium-phosphate-lipid complexes (CPLX), and (iii) annexin A5 (AnxA5), the principal lipid-dependent Ca(2+)-binding protein in MVs. We describe methods for reconstituting the nucleational core using a biomimetic approach and for analyzing the kinetics of its induction of mineral formation. The method is based on light scattering by the nascent crystallites at 340 nm and monitors mineral formation at regular intervals without disturbing the system using an automated plate reader. It yields precise replicate values that typically agree within less than 5%. As with MVs, mineral formation by the synthetic complex follows a sigmoidal pattern; following a quiescent induction period, rapid formation ensues for a limited time, followed by a distinct decline in rate that continues to slow, ultimately reaching a maximal asymptotic value. Key to quantization of mineral formation is the use of first-derivative analysis, which defines the induction time, the rate and the amount of initial mineral formation. Furthermore, using a five-parameter logistic curve-fitting algorithm, the maximal amount of mineral formation can be predicted accurately. Using these methods, we document the dramatic finding that AnxA5 synergistically activates PS-CPLX, transforming it from a very weak nucleator of mineral formation to a potent one. The methods presented should enable systematic study of the effects of numerous other factors thought to contribute to mineral formation.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0003-2697
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
367
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
159-66
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Kinetic analysis of mineral formation during in vitro modeling of matrix vesicle mineralization: effect of annexin A5, phosphatidylserine, and type II collagen.
pubmed:affiliation
Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, N.I.H., Extramural