CHARACTERIZATION OF LANGMUIR-BLODGETT-FILMS OF RHODOPSIN - THERMAL-STABILITY STUDIES

Two-dimensional close packing of purified bovine rhodopsin, made by th e Langmuir-Blodgett technique, was characterized by small angle x-ray scattering and nanogravimetric measurements. The area occupied by a mo lecule of rhodopsin in the film was similar to 1100 Angstrom(2) and th e periodicity of the layers resulted in 59 Angstrom. The circular dich roism measurements showed that bleached rhodopsin in Langmuir-Blodgett film had high thermal stability, in fact, reaching a temperature of 1 50 degrees C without a loss of the secondary structure, Moreover, when the film was made up in the dark, rhodopsin maintained its stability up to at least 200 degrees C and its characteristic absorbance peak at 500 nm up to about 90 degrees C.