The conformation of cyclodecapeptide loloatin C with obvious antibiotic activity has been investigated in 2,2,2-trifluoroethanol/sodium acetate buffer solution and then characterized by FT-IR, CD and NMR spectrum. T...The conformation of cyclodecapeptide loloatin C with obvious antibiotic activity has been investigated in 2,2,2-trifluoroethanol/sodium acetate buffer solution and then characterized by FT-IR, CD and NMR spectrum. The results of FT-IR show that there exists β-strand or β-turn secondary structure in the molecule. According to the CD spectrum, the helical turn is dominant but the β-turn structure also exists. Conformation of the whole molecule is probably a helical β-turn. The chemical shifts and coupling constants prove the existence of a β-structure in the regions of Val1, Orn2 and Leu3. NOESY data and temperature gradients of amide protons suggest that the molecular conformation is a dumbbell-like structure with the waist located between ornithyl (position 2) and D-phenylalanyl (position 7) and β-turn on both ends.展开更多
Aladan {β-[6＇-（N,N-dimethyl）amino-2＇-naphthoyl]alanine} and aladan-containing cyclodecapeptide [Ald^6]loloatin C were synthesized. The properties of their fluorescent behaviours both in aqueous buffer and micelle...Aladan {β-[6＇-（N,N-dimethyl）amino-2＇-naphthoyl]alanine} and aladan-containing cyclodecapeptide [Ald^6]loloatin C were synthesized. The properties of their fluorescent behaviours both in aqueous buffer and micelles created by sodium dodecylsulfate （SDS） and dodecylphosphorylcholine （DPC） were further investigated. It was found that in either of micelle systems, [Ald^6]loloatin C possesses red-shift emission maximum wavelength and higher quantum yield. This property could be useful in the research of peptide-cell membrane interaction.展开更多
文摘The conformation of cyclodecapeptide loloatin C with obvious antibiotic activity has been investigated in 2,2,2-trifluoroethanol/sodium acetate buffer solution and then characterized by FT-IR, CD and NMR spectrum. The results of FT-IR show that there exists β-strand or β-turn secondary structure in the molecule. According to the CD spectrum, the helical turn is dominant but the β-turn structure also exists. Conformation of the whole molecule is probably a helical β-turn. The chemical shifts and coupling constants prove the existence of a β-structure in the regions of Val1, Orn2 and Leu3. NOESY data and temperature gradients of amide protons suggest that the molecular conformation is a dumbbell-like structure with the waist located between ornithyl (position 2) and D-phenylalanyl (position 7) and β-turn on both ends.
文摘Aladan {β-[6＇-（N,N-dimethyl）amino-2＇-naphthoyl]alanine} and aladan-containing cyclodecapeptide [Ald^6]loloatin C were synthesized. The properties of their fluorescent behaviours both in aqueous buffer and micelles created by sodium dodecylsulfate （SDS） and dodecylphosphorylcholine （DPC） were further investigated. It was found that in either of micelle systems, [Ald^6]loloatin C possesses red-shift emission maximum wavelength and higher quantum yield. This property could be useful in the research of peptide-cell membrane interaction.
