ON THE ROLE OF MOLECULAR CLOSE PACKING ON THE PROTEIN THERMAL-STABILITY

Comparative study of photosynthetic reaction centres (RC) and bacterio rhodopsin (BR) in solution and LB films leads to the conclusion that t he molecular close packing plays a key role in the thermal stability o f proteins. LB organization of both RC and BR results in the strong im provement of the thermal stability, while when the films are prepared by only drying the solutions, the behaviour of RC and BR is different. RC reveal a decreased thermal stability, while in the case of BR ther e is no difference with respect to LB film. The last fact can be expla ined by taking into consideration the fact that BR molecules are organ ized into closely packed fragments of purple membranes in solution.