稀土氨基酸配合物的制备及能量作用参数的计算

报道了稀土氨基酸 RE(Gly) 3 Cl3 · 3 H2 O和 RE(His) 3 NO3 · 3 H2 O[其中 RE=Pr(III) ,Nd(III) ,Er(III) ]的制备 ,利用反射光谱数据 ,对各种 f - f的跃迁进行了指派 ,并对能量作用参数 F2 ,F4 ,F6,ξ4 f,δ,b1/ 2 ,F4 / F2 ,F6/ F2 进行了计算。结果证明 ,金属键 -配体键均有微小的共价性质 ,配位键具有一定的离域作用。     

Structure of the Ebola virus glycoprotein bound to an antibody from a human survivor

Ebola virus (EBOV) entry requires the surface glycoprotein (GP) to initiate attachment and fusion of viral and host membranes. Here we report the crystal structure of EBOV GP in its trimeric, pre-fusion conformation (GP1+GP2) bound to a neutralizing antibody, KZ52, derived from a human survivor of the 1995 Kikwit outbreak. Three GP1 viral attachment subunits assemble to form a chalice, cradled by the GP2 fusion subunits, while a novel glycan cap and projected mucin-like domain restrict access to the conserved receptor-binding site sequestered in the chalice bowl. The glycocalyx surrounding GP is likely central to immune evasion and may explain why survivors have insignificant neutralizing antibody titres. KZ52 recognizes a protein epitope at the chalice base where it clamps several regions of the pre-fusion GP2 to the amino terminus of GP1. This structure provides a template for unravelling the mechanism of EBOV GP-mediated fusion and for future immunotherapeutic development.     

水合单核铝到二聚铝形态的键合水分子活性变化研究

采用密度泛函方法研究了水溶液中单核铝形态和二聚铝形态中键合水分子的活性。计算结果表明,单核铝发生聚合形成二聚铝形态导致键合水分子的活性明显增加。对单核铝而言,水解和氟离子取代均会增加水分子的活性,而对于二聚铝形态,由于羟桥和分子内氢键的出现,水解和氟离子取代对活性无明显影响。该结果为进一步揭示铝形态的水解聚合机制提供了重要的动力学参数。     

Predominant naturally processed peptides bound to HLA-DR1 are derived from MHC-related molecules and are heterogeneous in size.

Peptides bound to class I molecules are 8-10 amino acids long, and possess a binding motif representative of peptides that bind to a given class I allele. In the only published study of naturally processed peptides bound to class II molecules (mouse I-Ab and I-Eb), these peptides were longer (13-17 amino acids) and had heterogenous carboxy terminals but precise amino-terminal truncations. Here we report the characterization of acid-eluted peptides bound to HLA-DR1 by high-performance liquid chromatography, mass spectrometry and microsequencing analyses. The relative molecular masses of the peptides varied between 1,602 and 2,996 (13-25 residues), the most abundant individual M(r) values being between 1,700 and 1,800, corresponding to an average peptide length of 15 residues. Complete sequence data were obtained for twenty peptides derived from five epitopes, of which all but one were from self proteins. These peptides represented sets nested at both the N- and C-terminal ends. Binding experiments confirmed that all of the isolated peptides had high affinity for the groove of DR1. Alignment of the peptides bound to HLA-DR1 and the sequences of 35 known HLA-DR1-binding peptides revealed a putative motif. Although peptides bound to class II molecules may have some related features (due to the nonpolymorphic HLA-DR alpha-chain), accounting for degenerate binding to different alleles, particular amino acids in the HLA-DR beta-chains presumably define allelic specificity of peptide binding.     

Two-dimensional crystallization technique for imaging macromolecules, with application to antigen--antibody--complement complexes

Two-dimensional crystals are formed from macromolecules bound on the surface of a lipid monolayer. A ligand linked to the lipid orientates the binding, and lateral diffusion of the lipids facilitates crystallization. The crystals are suitable for structural analysis by image processing of electron micrographs. An example is the formation of ordered arrays of antibodies on a monolayer of a lipid hapten, and subsequent decoration of these arrays with the first component of complement. Image processing indicates the arrangement of antibodies and the site of complement binding. This approach should be widely applicable to molecular complexes, such as those in replication, protein synthesis, hormone-receptor interaction and metabolic processes.     

巴马水与其他地区水的生命动力元素比较及与巴马人长寿关系的考察

分析了世界首位长寿地区——巴马地区长寿村井水和其他一些地区水中生命动力源相关元素,并根据第四统计力学群子统计参数理论,证实巴马地区长寿村饮用井水的生命动力元素群子参数与人体中胸腺、骨骼肌的很相近,其阴阳性属为（+）（+）（-）（+）高阳性水,具有良好的免疫作用及极佳壮阳、补气功能,而其他地区水的群子参数与胸腺相差较大,不能很好地作用于人体。巴马井水中所含有的锌、锰等生命动力源元素含水络合离子,对世界首寿的巴马人的长寿起到了决定性作用。     

具有非零元素链的矩阵为H矩阵的判定条件

目的解决判断一个具有非零元素链的矩阵为H矩阵的条件。方法采用逻辑推理的方法进行了证明。结果得到了当矩阵含有非零元素链时,判断其为H矩阵的条件。结论此结果对于控制系统的稳定性、特征值分布、线性方程组迭代解等方面都具有重要的理论意义。     

Structure of a Ran-binding domain complexed with Ran bound to a GTP analogue: implications for nuclear transport

The protein Ran is a small GTP-binding protein that binds to two types of effector inside the cell: Ran-binding proteins, which have a role in terminating export processes from the nucleus to the cytoplasm, and importin-beta-like molecules that bind cargo proteins during nuclear transport. The Ran-binding domain is a conserved sequence motif found in several proteins that participate in these transport processes. The Ran-binding protein RanBP2 contains four of these domains and constitutes a large part of the cytoplasmic fibrils that extend from the nuclear-pore complex. The structure of Ran bound to a non-hydrolysable GTP analogue (Ran x GppNHp) in complex with the first Ran-binding domain (RanBD1) of human RanBP2 reveals not only that RanBD1 has a pleckstrin-homology domain fold, but also that the switch-I region of Ran x GppNHp resembles the canonical Ras GppNHp structure and that the carboxy terminus of Ran is wrapped around RanBD1, contacting a basic patch on RanBD1 through its acidic end. This molecular 'embrace' enables RanBDs to sequester the Ran carboxy terminus, triggering the dissociation of Ran x GTP from importin-beta-related transport factors and facilitating GTP hydrolysis by the GTPase-activating protein ranGAP. Such a mechanism represents a new type of switch mechanism and regulatory protein-protein interaction for a Ras-related protein.     

水杨醛缩氨基酸、联吡啶配合物的电化学合成

以水杨醛缩L-苯丙氨基酸Schiff碱和2,2'-联吡啶为配体的非水溶剂中,用金属Cu、Zn、Ni为"牺牲"阳极,用电化学方法电解合成了Cu(Ⅱ)、Zn(Ⅱ)、Nj(Ⅱ)配合物.讨论了电化学合成的主要影响因素.通过元素分析、红外光谱、紫外光谱、热分析等对配体和配合物进行了表征,确定了配合物的化学组成,同时测定了Ni(Ⅱ)配合物的电化学性质.     

金湖凹陷闵桥玄武岩中微量元素向烃源岩的迁移及其地质意义

金湖凹陷闵桥构造阜宁组烃源岩中发育玄武岩，并且形成了玄武岩一烃源岩组合体。对阜宁组烃源岩中的微量元素系统分析发现，在生油门限深度附近，玄武岩被周围烃源岩有机质形成的有机酸蚀变改造，其中的微量金属元素被活化、溶蚀和迁移，然后沉淀于烃源岩中。其结果造成玄武岩原生气孔和收缩裂缝进一步扩大和连通，形成了良好的储集空间；同时周围烃源岩中微量金属元素含量显著增加。这种元素迁移是导致玄武岩蚀变、储集性能改善的重要原因，这也使有机质热演化得到某些过渡金属的催化作用成为可能。     

金湖凹陷闵桥玄武岩中微量元素向烃源岩的迁移及其地质意义

金湖凹陷闵桥构造阜宁组烃源岩中发育玄武岩,并且形成了玄武岩-烃源岩组合体.对阜宁组烃源岩中的微量元素系统分析发现,在生油门限深度附近,玄武岩被周围烃源岩有机质形成的有机酸蚀变改造,其中的微量金属元素被活化、溶蚀和迁移,然后沉淀于烃源岩中.其结果造成玄武岩原生气孔和收缩裂缝进一步扩大和连通,形成了良好的储集空间;同时周围烃源岩中微量金属元素含量显著增加.这种元素迁移是导致玄武岩蚀变、储集性能改善的重要原因,这也使有机质热演化得到某些过渡金属的催化作用成为可能.     

乙二醛邻氨基苯甲酸希夫碱过渡金属配合物的合成和表征

研究了过渡金属钴（Ⅱ）、镍（Ⅱ）、铜（Ⅱ）、锌（Ⅱ）与乙二醛双邻氨基苯甲酸希夫碱（H2L）配合物的合成,并用元素分析、摩尔电导、红外光谱、紫外-可见光谱、X-射线衍射物相分析、热重分析等测试手段进行了表征.结果表明,这是一类新的配合物,其组成为*4H2O(M=Co、Ni、Cu、Zn,L=乙二醛双邻氨基苯甲酸根),中心金属离子与希夫碱配体中的亚胺氮和羧酸根中的氧原子发生配位,配位数为4.