THE DUAL ROLE OF FIBRINOGEN AS INHIBITOR AND NUCLEATOR OF CALCIUM-PHOSPHATE PHASES - THE IMPORTANCE OF STRUCTURE

Constant composition and free drift methods have been used to investig ate the abilities of human serum albumin (HSA) and fibrinogen to influ ence calcium phosphate precipitation. Both molecules inhibit hydroxyap atite (HAP) crystal growth when present in the solution phase. Fibrino gen, when immobilized at hydrophobicized germanium or silica surfaces, is able to nucleate calcium phosphate phases; at clean germanium or s ilica surfaces, it appears to be inactive. The apparent configuration of fibrinogen molecules at germanium or silica surfaces on which octad ecyltrichlorosilane (OTS) was deposited probably exposes more negative sites for participation in nucleation. (C) 1996 Academic Press, Inc.