IN-VITRO PLASMA-PROTEIN ADSORPTION AND KALLIKREIN FORMATION ON 3-MERCAPTOPROPIONIC ACID, L-CYSTEINE AND GLUTATHIONE IMMOBILIZED ONTO GOLD

3-Mercaptopropionic acid (MPA), L-cysteine (L-cys), and glutathione (G SH) monolayers were immobilized onto gold and used in in vitro protein tests. The surfaces were characterized with ellipsometry, static cont act angle measurements, atomic force microscopy, and Fourier transform infrared reflection absorption spectroscopy (FT-IRAS). After incubati ons in human plasma and antibody solutions, the surface antisera bindi ng patterns were determined with ellipsometry. Using serum instead of plasma, complement activation was studied in the same fashion. Activat ed coagulation Factor XII and kallikrein formation on the surfaces and in the plasma were studied using a kallikrein-specific colorimetric a ssay. 3-Mercaptopropionic acid indicated contact activation of coagula tion but L-cysteine did not. Glutathione displayed low deposition of p lasma proteins, large deposition of proteins from serum, and did not p romote kallikrein formation. None of the surfaces could be attributed complement activating properties, as determined by antibody deposition . The present study demonstrates that surface biology in complex model systems can be conveniently studied in vitro through systematic and w ell defined surface modifications. (C) 1994 John Wiley and Sons, Inc.