101. Binding of monofluorophosphate to α2-macroglobulin and C3.
- Author
-
Rigalli, A., Esteban, L., Pera, L., and Puche, R.
- Abstract
After administering an oral dose of monofluorophosphate (MFP) to human beings or rats, a fraction of the drug appears in plasma that is bound to proteins, establishing a previously undetected compartment of nondiffusible fluoride. This article documents experiments performed in vitro, describing the binding of MFP to two plasma globulins: α
2 -macroglobulin and C3 (a β-globulin). MFP binds irreversibly to these proteins through a stable bond. MFP binds to purified α2 -macroglobulin or to C3 with a molar ratio MFP: protein close to unity. MFP binding reduces significantly the biological activity of these proteins, which share in common a macrocyclic 4-residue ring thiolactone (Cys—Gly—Glu—Glu). The binding site of MFP is as yet unknown. Protein-bound MFP appeared in the plasma of volunteers during the 5–7 hours following intake. Peak concentration of protein-bound MFP and maximal reduction of α2 -macroglobulin activity was observed 2 hours after intake. Clearance of protein-bound MFP coincided with the return of α2 -macro-globulin to basal levels. [ABSTRACT FROM AUTHOR]- Published
- 1997
- Full Text
- View/download PDF