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
In this paper the solution conformation of the response regulator proteins from Deinococcus radiodurans was studied by small-angle X-ray scattering （SAXS）. The SAXS curves of Dr-rrA in solutions were obtained at Bea...In this paper the solution conformation of the response regulator proteins from Deinococcus radiodurans was studied by small-angle X-ray scattering （SAXS）. The SAXS curves of Dr-rrA in solutions were obtained at Beamline 1W2A of Beijing Synchrotron Radiation Facility （BSRF）. Two possible conformations of the response regulator proteins, compact and incompact conformations, have been represented by the known crystallographic structures. And theoretical solution scattering curves of the two possible conformations were calculated and fitted to the experimental scattering curve of Dr-rrA, respectively. The result indicates that the solution conformation of the response regulator proteins is inclined to the compact one, which is in agreement with the result of biochemical experiments.展开更多
The phase sensitive NOESY spectrum of oridonin was treated using Full Relaxation Matrix Analysis(FRMA) approach, and the cross relaxation rates of proton pairs were obtained by diagonalizing the NOE matrix of oridonin...The phase sensitive NOESY spectrum of oridonin was treated using Full Relaxation Matrix Analysis(FRMA) approach, and the cross relaxation rates of proton pairs were obtained by diagonalizing the NOE matrix of oridonin. The inter proton distances were calculated according to 1/r6 ij ∝σij. The three-dimensional structure of oridonin in solution was calculated by the combination of WUPH, WUPH-S method with molecular mechanics minimization on the basis of NMR experiment.展开更多
Two dimensional 1H NMR techniques were used to determine the solution structure of C10, a cyclopeptide synthesized in the laboratory. Complete proton resonance assignments were obtained using 2 D DQF COSY, TOC...Two dimensional 1H NMR techniques were used to determine the solution structure of C10, a cyclopeptide synthesized in the laboratory. Complete proton resonance assignments were obtained using 2 D DQF COSY, TOCSY, and NOESY experiments. The cross peak volumes in the NOESY spectra were used to calculate the C10 structure. The conformation showed that the four side chains of the lysine residues faced the same side of the cyclopeptide ring. 展开更多
he Raman spectra of the antibacterial peptide βcomponent of silkworm· Bombyx Mori· pupae in aqueous solution have been studied. The results show that its mainchain consists of lots of αhelicals and only a ...he Raman spectra of the antibacterial peptide βcomponent of silkworm· Bombyx Mori· pupae in aqueous solution have been studied. The results show that its mainchain consists of lots of αhelicals and only a few βsheets and βturns. This suggests that the antibacterial peptide βcomponent may be the glycopeptide.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.
基金Supported by National Natural Science Foundation of China(10979005)National Basic Research Program of China(2009CB918600)
文摘In this paper the solution conformation of the response regulator proteins from Deinococcus radiodurans was studied by small-angle X-ray scattering （SAXS）. The SAXS curves of Dr-rrA in solutions were obtained at Beamline 1W2A of Beijing Synchrotron Radiation Facility （BSRF）. Two possible conformations of the response regulator proteins, compact and incompact conformations, have been represented by the known crystallographic structures. And theoretical solution scattering curves of the two possible conformations were calculated and fitted to the experimental scattering curve of Dr-rrA, respectively. The result indicates that the solution conformation of the response regulator proteins is inclined to the compact one, which is in agreement with the result of biochemical experiments.
基金Supported by the National Natural Science Foundation of China
文摘The phase sensitive NOESY spectrum of oridonin was treated using Full Relaxation Matrix Analysis(FRMA) approach, and the cross relaxation rates of proton pairs were obtained by diagonalizing the NOE matrix of oridonin. The inter proton distances were calculated according to 1/r6 ij ∝σij. The three-dimensional structure of oridonin in solution was calculated by the combination of WUPH, WUPH-S method with molecular mechanics minimization on the basis of NMR experiment.
文摘Two dimensional 1H NMR techniques were used to determine the solution structure of C10, a cyclopeptide synthesized in the laboratory. Complete proton resonance assignments were obtained using 2 D DQF COSY, TOCSY, and NOESY experiments. The cross peak volumes in the NOESY spectra were used to calculate the C10 structure. The conformation showed that the four side chains of the lysine residues faced the same side of the cyclopeptide ring.
文摘he Raman spectra of the antibacterial peptide βcomponent of silkworm· Bombyx Mori· pupae in aqueous solution have been studied. The results show that its mainchain consists of lots of αhelicals and only a few βsheets and βturns. This suggests that the antibacterial peptide βcomponent may be the glycopeptide.
