PLASMA-PROTEIN AND ANTISERA INTERACTIONS WITH L-CYSTEINE AND 3-MERCAPTOPROPRIONIC ACID MONOLAYERS ON GOLD SURFACES

Thiols with varying functionalities are well suited for immobilization onto gold. In the present study surfaces modified with L-cysteine (zwitterionic, neutral) and 3-mercaptoproprionic acid (MPA, negatively charged) were incubated in human plasma, and the antisera binding patterns of four proteins were determined by ellipsometry. Significant differences among the surfaces were observed. Plasma-treated L-cysteine surfaces bound low amounts of both anti-fibrinogen (a-FG) and anti high molecular weight kininogen (a-HMWK), while MPA surfaces bound increased amounts of a-HMWK but no a-FG. The results demonstrate that the surface biology in complex, but biologically relevant, systems may be conveniently studied through a combination of systematic surface modifications, antisera techniques, and ellipsometry.