A Few Applications Of NMR Techniques To Analytical Studies Of Organic Molecules And Peptides

This thesis focuses on a few applications of high resolution NMR spectroscopy in the study of the structure and the biological function of organic molecules and peptides. The solid and liquid NMR methods of studying membrane-active antimicrobial peptides are also outlined here.1.The methods and applications of multidimentional NMR spectroscopy in the study of the structure and the biological function of organic molecule and peptide are simply reviewed.NMR methods for studying the structures of antimicrobial peptides in lipid bilayers as well as the effect of antimicrobial peptides on model membranes are summed up,with an emphasis on solid state NMR methods.2.The ¹H and ¹³C NMR spectral assignments for three new benzothieno [3',2':5,6]pyrido[4,3-d]pyrimidin-4(3H)-ones derivatives were achieved by concerted application of one and two-dimensional NMR techniques(¹H NMR,¹³C NMR,T₁, DEPT,gCOSY,gHSQC and gHMBC).These assignments are helpful for the study of the mechanism of biological activities.3.The high-resolution liquid NMR was used to investigate the mechanism of the interaction of D1 prolease with the precursor to the D1 protein(_pD1)in photosystemâ…¡(PSâ…¡).Synthetic oligopeptide S24 corresponding to the carboxyl-terminal COOH-terminal)24 amino acids of the _PD1 peptide of spinach,was shown to be a useful substrate for enzymatic analysis.In order to reveal the mechanism of the enzymatic reaction,the assighments of the proton spectra of oligopeptide S24 in aqueous solution were made by interactive interpretation of the two-dimensional TOCSY and NOESY spectra.The estimate of secondary structure is provided by the simple method of"Chemical Shift Index(CSI)",the observed interresidue sequential and medium range NOEs and CD studies.The results show that oligopeptide S24 adopts a random coil conformation in aqueous solution.