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分别使用荧光光谱法、 ~1H和~(31)P核磁方法对腺苷-5′-三磷酸(ATP)和多种L-精氨酸衍生物(L)的相互作用做了系统的研究, 得到了一些有意义的结果.在荧光滴定实验中, L对ATP有很强的荧光猝灭作用, 说明两者有较强的相互作用. ~1H和~(31)P核磁结果进一步证实了L与ATP的识别位点在ATP的嘌呤环和磷酸链上, 结合力为氢键和静电作用. 另外, 用~(31)P 核磁滴定的方法考察了L对ATP水解的影响, 发现不同的精氨酸衍生物对ATP水解的催化影响有很大的差异, 说明L对ATP的识别和催化其水解作用有较强的选择性. 此识别及催化作用的研究对深入理解精氨酸残基在ATP合酶中起到"触点"作用有一定的参考价值. 相似文献
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以L-脯氨酸为原料.合成了4个新的光反应物--邻苯二甲酰基聚L-脯氨酸肽,其结构经1H NMR,13C NMR,FAB-MS和元素分析表征. 相似文献
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脯氨酸类衍生物结构独特,鲜有报道利用核磁共振(nuclear magnetic resonance,NMR)技术对氨基酸的手性进行鉴别.利用多种NMR技术:1H NMR、1H-1H同核位移相关谱(1H-1H COSY)、1H-1H质子全相关谱(1H-1H TOCSY)、1H-1H核Overhauser效应谱(1H-1H NOESY)、13C NMR、无畸变的极化转移增强法(DEPT135°)、1H-13C检出1H的异核单量子相干(1H-13C HSQC)和1H-13C检出1H的异核多键相关(1H-13C HMBC),对脯氨酸类N-酰胺衍生物两种构象异构体的1H和13C NMR进行了全归属,确定了室温下在二甲基亚砜(DMSO)中L型和D型的顺反异构体以相同的比例同时存在. 相似文献
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光谱法分析乙丙共聚物的序列结构及链节比 总被引:3,自引:0,他引:3
用FTIR, 1 H NMR和 13 C NMR分析乙丙共聚物的序列结构与链节比. 通过对乙丙共聚物 1 H NMR, 13 C NMR和 13 C-1 H二维核磁共振谱的综合分析, 提出了与前人不同的归属, 并提出了不同位置碳原子积分面积相关性分析方法, 该方法避免了烦琐的理论计算, 可简便地得到乙丙共聚物的主要序列结构. 通过比较 1 H NMR和 13 C NMR计算乙丙共聚物中乙烯、 丙烯链节比, 表明可以用 1 H NMR代替 13 C NMR完成对乙丙共聚物中乙烯、 丙烯链节比的定量计算. 相似文献
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The adsorption of phosphate on goethite is generally modeled by assuming a simple ligand exchange reaction with surface hydroxyl groups. This study investigates the binding forms of phosphate on goethite by evaluating the proton interaction and surface charge change during phosphate adsorption. It is found that OH(-) release stoichiometry increases with phosphate coverage, which suggests that different mechanisms predominate at different phosphate loadings. It demonstrates that surface binding changes from monodentate complexation to bidentate complexation with increasing surface phosphate coverage. The net OH(-) release accompanying this transformation is best interpreted with a 2pK(a) multisite model. 相似文献
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本文通过对环状磷酸酯和环状亚磷酸酯类化合物的分子力学计算,观察到^1^7ONMR化学位移的变化同时受到氧原子局部范德华相互综合利用(E~V~D~W~-~O)和局部偶极相互作用能(E~i~i~p-~O)的影响。此外,在上述两类化合物中,环外氧原子的δ-压缩效应极为明显,这主要是由于该氧原子局部范德华相互作用能起决定作用的缘故。同时,经对二烷基砜类化合物的分子力学计算,首次获得^3^3SNMR化学位移和硫原子局部范德华相互作用能E~V~D~W~-~S之间良好的线性关系。 相似文献
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新型磷酸钒孔道结构化合物(H3NCH2CH2NH3)3- [ (VO)4(PO4)2 (HPO4)4]的水热 合成及结构表征 总被引:12,自引:0,他引:12
以有机分子乙二胺作为模板剂合成了新型磷酸钒孔道化合物(H3NCH2CH2NH3)3^-[(VO)4(PO4)2(HPO4)4,并通过X射线单晶衍射实验进行了结构表征,晶体学数据为:C2/c,a=1.8505(9)nm,b=0.7089(4)nm,c=2.3304(10)nm,β=96.43(3)°,V-3.038(3)nm^3,Z=8,R=0.067,Rw^b=0.1635,该化合物具有非常独特和规整的二维孔道骨架结构,进一步的晶体化学研究表明该化合物为一新的VPO物相。 相似文献
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合成和表征了新的三元配合物: [Cu(L-His)(5'-AMP)]Cl2.4H2O,[Cu(L-His)(5'-GMP)]Cl2, [Cu(L-His)(5'-IMP)]Cl2.2H2O,[Cu(l-Lys)2(5'-GMP)]Cl2.6H2O, Na2[Cu(L-Lys)2(5'-GMPH_2)].6H2O,Na2[Cu(L-Lys)2(5'-GTPH_2)].6H2O, Na2[Cu(L-Lys)2(5'-IMPH_2)].10H2O. IR及NMR谱表明, 5'-嘌呤核苷酸以嘌呤碱基上的7-N原子与Cu(II)配位。在5'-嘌呤核苷酸形成的配合物中, 磷酸根不参与配位, 但是Na2.5'-GMPH-2和Na.5'-GTPH-2的磷酸根参与配位, 而Na2.5'-IMPH-2的磷酸根不参与配位。 相似文献
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本文报道了一种用水溶性CdTe量子点传感磷酸根离子的发光方法. 该法是基于在具有自然尺寸分布的单一量子点样品中三价铕所诱导的能量转移. 实验表明, 三价铕离子能诱导表面带有负电荷的量子点发生簇集, 引发量子点间的能量转移, 导致显著的发光猝灭和发射位移. 当在上述体系中加入磷酸根离子时, 由于它与三价铕离子强烈的配位竞争瓦解了所形成的量子点簇集, 因此引起量子点起始发光的逐渐恢复. 该法具有高的灵敏度、大的发射位移和可测颜色变化等量子点发光优势, 用于环境水样中磷酸根离子的测定, 结果令人满意. 相似文献
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T Grune W Siems G Gerber Y V Tikhonov A M Pimenov R T Toguzov 《Journal of chromatography. A》1991,563(1):53-61
The pool of purine compounds was analysed in liver, skeletal muscle and blood of mice during the growth of Ehrlich ascites tumour cells. Three fast isocratic high-performance liquid chromatographic methods were used. (1) Determination of nucleotides by an isocratic ion-pair reversed-phase chromatography with a 10 mM ammonium phosphate buffer containing acetonitrile and tetrabutylammonium phosphate. (2) Separation of nucleosides and nucleobases in cell extracts by a reversed-phase system with methanol and 50 mM potassium phosphate buffer as eluent. (3) Nucleosides and nucleobases in body fluids were analysed by a reversed-phase system with 10 mM potassium phosphate containing methanol. These methods allow the rapid determination of purine compounds in small biological samples from various cell types and body fluids, with high accuracy and sensitivity. The pool of cellular nucleotides increased during the exponential phase of tumour growth. Adenosine accumulated significantly in all tissues in the stationary phase of tumour growth. 相似文献
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Interaction between Potassium Phosphate Bu er Solution and Modeling Cell Membrane Investigated by Sum Frequency Generation Vibrational Spectroscopy (cited: 1)
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Potassium phosphate buffer solution has been widely used in the biological experiments, which represents an important process of the interaction between ions and biomolecules, yet the in fluences of potassium phosphate on biomolecules such as the cell membrane are still poorly understood at the molecular level. In this work, we have applied sum frequency generation vibrational spectroscopy and carried out a detailed study on the interaction between potassium phosphate buffer solution (PBS) and negative 1,2-dimyristoyl-d54-sn-glycero-3-[phospho-rac-(1-glycerol)] (d54-DMPG) lipid bilayer in real time. The PBS-induced dynamic change in the molecular structure of d54-DMPG lipid bilayer was monitored using the spectral features of CD2, CD3, lipid head phosphate, and carbonyl groups for the first time. It is found that K+ can bind to the cell membrane and cause the signal change of CD2, CD3, lipid head phosphate, and carbonyl groups quickly. Potassium PBS interacts with lipid bilayers most likely by formation of toroidal pores inside the bilayer matrix. This result can provide a molecular basis for the interpretation of the effect of PBS on the ion-assisted transport of protein across the membrane. 相似文献
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