LARGE-SCALE RECRYSTALLIZATION OF THE S-LAYER OF BACILLUS-COAGULANS E38-66 AT THE AIR-WATER-INTERFACE AND ON LIPID FILMS

S-layer protein isolated from Bacillus coagulans E38-66 could be recry stallized into large-scale coherent monolayers at an air/water interfa ce and on phospholipid films spread on a Langmuir-Blodgett trough. Bec ause of the asymmetry in the physicochemical surface properties of the S-layer protein, the subunits were associated with their more hydroph obic outer face with the air/water interface and oriented with their n egatively charged inner face to the zwitterionic head groups of the di palmitoylphosphatidylcholine and dipalmitoylphosphatidylethanolamine ( DPPE) monolayer films. The dynamic crystal growth at both types of int erfaces was first initiated at several distant nucleation points. The individual monocrystalline areas grew isotropically in all directions until the front edge of neighboring crystals was met. The recrystalliz ed S-layer protein and the S-layer-DPPE layer could be chemically cros s-linked from the subphase with glutaraldehyde.