POLYMER ULTRATHIN FILMS WITH IMMOBILIZED PHOTOSYNTHETIC REACTION-CENTER PROTEINS

Mixed monolayers of lipids with photosynthetic reaction center protein s (RCs) from Rb. sphaeroides and C. aurantiacus were studied and the o ptimum conditions for stable films fabrication were determined, The fo llowing synthetic: ACPE, TDA, PDA, DODL and natural lipids: PE, PC wer e used. The rate of polymerization of the mixed ACPE-RC and TDA-RC mon olayers is lower than those for pure lipid-like monomers on the air/wa ter interface but high enough for the: fast preparation of the polymer films. The optical and photoelectrical measurements provide evidence for an orientation of RCs (from Rb. sphaeroides) on interface, Hydroph ilic H-subunit in the mixed ACPE-RCs and DODL-RCs monolayers is prefer entially oriented towards water as in the pure RC monolayers. Opposite rientation was found with TDA-RCs and PDA-RCs films. No preferential orientation was found for lipid-RCs (C. aurantiacus) monolayers probab ly because of the low asymmetry of hydrophobic subunits (M and L) of t hese RCs.