LASER RAMAN SCATTERING FROM BIOLOGICAL MACROMOLECULES

本提案的目的是确定大分子

The objectives of this proposal are to determine the macromolecular conformation and macromolecular dynamics of enzymes, nucleic acids, and membrane components in a more quantitative manner in aqueous solutions or aqueous dispersions than has previously been possible using both classical and resonance laser Raman scattering. The use of both flow freeze-quench and steady flow techniques with vidicom detection of the scattered Raman signal should give important information on the structure of transients of both enzyme-substrate intermediates and intermediates in the pathway of protein folding. Preliminary studies on conformation of deoxyribonucleotide oligomers show remarkable differences between the conformation in the crystal and in solution. It is proposed to develop a systematic study of nucleic base sequence dependence of oligonucleotide secondary structure. Two new spectrometers -- one using a freeze-quench spinning cell technique and the other using a steady-state flow system -- have been developed and it is proposed to use these instruments for studying enzyme-substrate complexes. New methods for obtaining the secondary structure of both the equilibrium conformational states and the kinetic conformational states in a protein during refolding using classical Raman technique will be developed. New methods for determining the secondary structure dependence of fluctuations leading to hydrogen-deuterium exchange are also being developed. Since many health related problems are closely linked to the proper function of biological macromolecules, a better understanding of the dynamics of these molecules should help in both preventive and general health care.