Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1992-12-1
pubmed:abstractText
Of the major human bile salts, only the glycine-conjugated dihydroxy species prevent the transformation of amorphous calcium phosphate to calcium hydroxyapatite, a component of gallstones; we have proposed that this inhibition occurs by competition between the bile salt and HPO4(2-) anions for binding site on the apatite crystal embryo. Now we show that the binding affinity of bile salts to fully mature hydroxyapatite has the following order: glycine-conjugated dihydroxy salts > taurine-conjugated dihydroxy salts > glycocholate approximately taurocholate. Glycine-conjugated dihydroxy bile salts bound with high affinity as "premicellar" aggregates, but the remaining species appeared to bind as a wider range of aggregate sizes. Glycochenodeoxycholate binding was decreased as the pH increased from 6.6 to 9.8 and the apatite surface charge reversed from net positive to net negative. Binding was competitively inhibited by HPO4(2-), but not by H2PO4-. Ca2+ promoted the binding of glycochenodeoxycholate, taurochenodeoxycholate and glycocholate, and for the latter two bile salts the increase was associated with enhanced "premicellar" binding. The binding of taurocholate was not influenced by Ca2+. When either glycocholate or taurocholate was mixed with glycochenodeoxycholate, mixed aggregates were formed that had a lower affinity for apatite than had pure glycochenodeoxycholate aggregates. Because only glycine-conjugated dihydroxy bile salts inhibit apatite formation, these results suggest that inhibition depends on high-affinity "premicellar" bile salt-apatite binding.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Anions, http://linkedlifedata.com/resource/pubmed/chemical/Bile Acids and Salts, http://linkedlifedata.com/resource/pubmed/chemical/Calcium Phosphates, http://linkedlifedata.com/resource/pubmed/chemical/Durapatite, http://linkedlifedata.com/resource/pubmed/chemical/Glycine, http://linkedlifedata.com/resource/pubmed/chemical/Glycochenodeoxycholic Acid, http://linkedlifedata.com/resource/pubmed/chemical/Glycocholic Acid, http://linkedlifedata.com/resource/pubmed/chemical/Hydroxyapatites, http://linkedlifedata.com/resource/pubmed/chemical/Micelles, http://linkedlifedata.com/resource/pubmed/chemical/Phosphates, http://linkedlifedata.com/resource/pubmed/chemical/Taurine, http://linkedlifedata.com/resource/pubmed/chemical/Taurochenodeoxycholic Acid, http://linkedlifedata.com/resource/pubmed/chemical/Taurocholic Acid, http://linkedlifedata.com/resource/pubmed/chemical/alpha-tricalcium phosphate, http://linkedlifedata.com/resource/pubmed/chemical/amorphous calcium phosphate, http://linkedlifedata.com/resource/pubmed/chemical/calcium phosphate, http://linkedlifedata.com/resource/pubmed/chemical/dicalcium phosphate anhydrous, http://linkedlifedata.com/resource/pubmed/chemical/monocalcium phosphate, http://linkedlifedata.com/resource/pubmed/chemical/tetracalcium phosphate
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0270-9139
pubmed:author
pubmed:issnType
Print
pubmed:volume
16
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1280-9
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Interaction of bile salts with calcium hydroxyapatite: inhibitors of apatite formation exhibit high-affinity premicellar binding.
pubmed:affiliation
Department of Internal Medicine, University of Texas Medical Branch, Galveston 77550.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't