NMR spectroscopy and X-ray crystallography are two premium methods for determining the atomic structures of macro-biomolecular complexes.Each method has unique strengths and weaknesses.While the two techniques are hig...NMR spectroscopy and X-ray crystallography are two premium methods for determining the atomic structures of macro-biomolecular complexes.Each method has unique strengths and weaknesses.While the two techniques are highly complementary,they have generally been used separately to address the structure and functions of biomolecular complexes.In this review,we emphasize that the combination of NMR spectroscopy and X-ray crystallography offers unique power for elucidating the structures of complicated protein assemblies.We demonstrate,using several recent examples from our own laboratory,that the exquisite sensitivity of NMR spectroscopy in detecting the conformational properties of individual atoms in proteins and their complexes,without any prior knowledge of conformation,is highly valuable for obtaining the high quality crystals necessary for structure determination by X-ray crystallography.Thus NMR spectroscopy,in addition to answering many unique structural biology questions that can be addressed specifically by that technique,can be exceedingly powerful in modern structural biology when combined with other techniques including X-ray crystallography and cryo-electron microscopy.展开更多
A series of lanthanide complexes with the 3,4,5-trimethoxybenzoic acid （3,4,5-tmoba） and 1,10-phenanthroline（phen）, [Ln（3,4,5-tmoba）3phen]2（Ln = Pr（l）, Nd （2） and Ho（3））, have been synthesized and charac...A series of lanthanide complexes with the 3,4,5-trimethoxybenzoic acid （3,4,5-tmoba） and 1,10-phenanthroline（phen）, [Ln（3,4,5-tmoba）3phen]2（Ln = Pr（l）, Nd （2） and Ho（3））, have been synthesized and characterized by a series of techniques including elemental analysis, IR spectra, X-ray crystallography and TG/DSC-FTIR technology. The three complexes have two kinds of coordination modes, in which the Pr3＋ and Nd3＋ cations are nine-coordinated and the Ho3＋ cation is eight-coordinated. The three-dimensional IR accumulation spectra of gaseous products for complexes 1-3 were analyzed and the gaseous products were identified by the typical IR spectra obtained from the 3D surface graphs. Meanwhile, we obtained the activation energy E of the first steps of complexes 1-3 by the integral isoconversional non-linear （NL-INT） method and discussed the non-isothermal kinetics of complexes 1-3 using the Malek method. Finally, SB（m, n） was defined as the kinetic method of the first-step thermal decomposition. The thermodynamic parameters △G≠, △H≠ and △S≠ of activation at the peak temperature were also calculated.展开更多
基金supported by grants from the Research Grants Council of Hong Kong to M.Z.supported by the National Major Basic Research Program of China (Grant No. 2011CB910500)+3 种基金the National Natural Science Foundation of China (Grant No. 31070657)the Knowledge Innovation Program of the Chinese Academy of Sciences (Grant No. KSCX2-YW-R-154)The NMR spectrometers used in our studies were funded by donations from the Hong Kong Jockey Club Charity Foundationthe Special Equipment Grant from RGC of Hong Kong (Grant No. SEG_HKUST06)
文摘NMR spectroscopy and X-ray crystallography are two premium methods for determining the atomic structures of macro-biomolecular complexes.Each method has unique strengths and weaknesses.While the two techniques are highly complementary,they have generally been used separately to address the structure and functions of biomolecular complexes.In this review,we emphasize that the combination of NMR spectroscopy and X-ray crystallography offers unique power for elucidating the structures of complicated protein assemblies.We demonstrate,using several recent examples from our own laboratory,that the exquisite sensitivity of NMR spectroscopy in detecting the conformational properties of individual atoms in proteins and their complexes,without any prior knowledge of conformation,is highly valuable for obtaining the high quality crystals necessary for structure determination by X-ray crystallography.Thus NMR spectroscopy,in addition to answering many unique structural biology questions that can be addressed specifically by that technique,can be exceedingly powerful in modern structural biology when combined with other techniques including X-ray crystallography and cryo-electron microscopy.
基金the National Natural Science Foundation of China (21073053,21073052,20773034)the Natural Science Foundation of Hebei Province (B2012205022)
文摘A series of lanthanide complexes with the 3,4,5-trimethoxybenzoic acid （3,4,5-tmoba） and 1,10-phenanthroline（phen）, [Ln（3,4,5-tmoba）3phen]2（Ln = Pr（l）, Nd （2） and Ho（3））, have been synthesized and characterized by a series of techniques including elemental analysis, IR spectra, X-ray crystallography and TG/DSC-FTIR technology. The three complexes have two kinds of coordination modes, in which the Pr3＋ and Nd3＋ cations are nine-coordinated and the Ho3＋ cation is eight-coordinated. The three-dimensional IR accumulation spectra of gaseous products for complexes 1-3 were analyzed and the gaseous products were identified by the typical IR spectra obtained from the 3D surface graphs. Meanwhile, we obtained the activation energy E of the first steps of complexes 1-3 by the integral isoconversional non-linear （NL-INT） method and discussed the non-isothermal kinetics of complexes 1-3 using the Malek method. Finally, SB（m, n） was defined as the kinetic method of the first-step thermal decomposition. The thermodynamic parameters △G≠, △H≠ and △S≠ of activation at the peak temperature were also calculated.
