Zincbindpredict—Prediction of Zinc Binding Sites in Proteins

Background: Zinc binding proteins make up a significant proportion of the proteomes of most organisms and, within those proteins, zinc performs rôles in catalysis and structure stabilisation. Identifying the ability to bind zinc in a novel protein can offer insights into its functions and the mechanism by which it carries out those functions. Computational means of doing so are faster than spectroscopic means, allowing for searching at much greater speeds and scales, and thereby guiding complimentary experimental approaches. Typically, computational models of zinc binding predict zinc binding for individual residues rather than as a single binding site, and typically do not distinguish between different classes of binding site—missing crucial properties indicative of zinc binding. Methods: Previously, we created ZincBindDB, a continuously updated database of known zinc binding sites, categorised by family (the set of liganding residues). Here, we use this dataset to create ZincBindPredict, a set of machine learning methods to predict the most common zinc binding site families for both structure and sequence. Results: The models all achieve an MCC ≥ 0.88, recall ≥ 0.93 and precision ≥ 0.91 for the structural models (mean MCC = 0.97), while the sequence models have MCC ≥ 0.64, recall ≥ 0.80 and precision ≥ 0.83 (mean MCC = 0.87), with the models for binding sites containing four liganding residues performing much better than this. Conclusions: The predictors outperform competing zinc binding site predictors and are available online via a web interface and a GraphQL API.     

One-pot selective cleavage of prenyl carbamates using iodine in methanol followed by zinc

The prenyloxycarbonyl (Preoc) moiety was efficiently removed from carbamates to provide the corresponding amines in good to excellent yields (63-88%) by using iodine in methanol followed by treatment of the resulting β-methoxyiodides by zinc powder. The reaction conditions are compatible with the presence of a number of functional groups such as Boc and Cbz carbamates, sulfides, double bonds, indoles and aromatic methyl ethers.     

磁控溅射方法生长的氮氧锌薄膜的光学特性

氧化锌(ZnO)是一种具有六方结构的宽禁带Ⅱ--Ⅵ族半导体材料，室温下能带带隙Eg为3.37eV。由于氧化锌在室温条件下具有较高的激子束缚能(60meV)，保证了其在室温下较强的激子发光。此外氧化锌还具有较高的热稳定性和抗化学腐蚀特性，因而被认为是制作紫外半导体激光器的合适材料。自1997年首次发现ZnO室温紫外受激发射以来，ZnO已成为继GaN之后紫外发射材料的又一研究热点。但是，目前对于p型氧化锌及其发光器件的研究仍处于探索阶段，对其光电特性的研究仍需要更多投入。本文利用磁控溅射方法制备出氮氧锌薄膜样品，并通过在氧气气氛下退火处理，改变薄膜样品中氮的含量。通过X射线衍射谱、X射线光电子能谱、光致发光谱及喇曼光谱的测试，研究了氮在氧化锌薄膜中的含量变化以及氮对氧化锌薄膜的结构和光学特性的影响。     

2-Ketogluconic acid production by acetobacter pasteurianus

Production of 2-ketogluconic acid in batch fermentation was investigated.Acetobacter pasteurianus ATCC 6438, which produces selectively 2-ketogluconic acid only, was used. The optimal pH for glucose dehydrogenation to gluconate by resting cells was 5.0 and for gluconate dehydrogenation to 2-ketogluconate 4.25. When glucose medium was used, the 89% yield was achieved after 90 h. For the optimal productivity, medium containing glucose and gluconate with the molar glucose:gluconate ratio 7.4 was proposed, and the yield of 92% after 56 h was achieved. This composition of medium led to the elevation of dissolved oxygen concentration during fermentation. It consequently resulted in elevated gluconate dehydrogenase activity being discussed as the rate-limiting activity of the batch production.     

双—（磷酸二甲酯）合锌的结构与光谱

由四圆衍射仪收集标题化合物Zn(DMP)_2的衍射数据。用直接法解出其单晶结构为:空间群Pc,a=0.9361(2),b=1.0519(3).c=1.2028(2)nm. β=91.01(2)°,Z=4.锌原子与4个配体的非酯氧原子形成ZnO_4四面体。具有近似的T_d对称性。相邻锌原子由“O—P—O”桥相连,形成一维链状配位聚合物。红外光谱证实O—P—O基的形成。对某些重要的谱带进行了解释,说明了Zn—O振动与配位阴离子振动的混合情况。     

The design and synthesis of novel derivatives of the dopamine uptake inhibitors GBR 12909 and GBR 12935. High-affinity dopaminergic ligands for conjugation with highly fluorescent cadmium selenide/zinc sulfide core/shell nanocrystals

There is a growing demand for compounds with very high affinities for the dopamine transporter protein (DAT) that can be conjugated to fluorescent markers such as cadmium selenide/zinc sulfide core/shell nanocrystals. This paper describes the design and synthesis of two derivatives of the DAT antagonists GBR 12935 and GBR 12909. These compounds have a high biological affinity for DAT and may be conjugated to nanocrystals via a thiol linkage without a significant reduction in their biological activity. Such conjugates may be used in fluorescent imaging studies.     

Crystallization and Reduction of Sol-Gel-Derived Zinc Oxide Films by Irradiation with Ultraviolet Lamp

Structural changes in sol-gel films with photo-irradiation were investigated using zinc oxide (ZnO) derived from zinc acetate. The exposure of the films to an ultraviolet lamp induced hexagonal ZnO crystals in a relatively dense amorphous structure. On the other hand, the formation of zinc metal was found in a porous gel film. The photo-induced crystallization and reduction are ascribed to the electronic excitation in the metastable non-crystalline states.     

二维锌枝晶生长行为研究

采用恒电压方法得到了不同电解质浓度和电压下金属锌二维电沉积生长的形貌分布图．在枝晶生长条件下,研究了支持电解质、全氟表面活性剂和脉冲电压等对锌枝晶生长行为的影响，并检测了电解池中Zn^2 的浓度分布．实验结果表明：支持电解质、表面活性剂和脉冲电压改变了阴极附近的电场分布和Zn^2 的浓度分布，对沉积物形貌产生很大的影响．同时发现，Zn^2 仅通过电迁移作用到达阴极附近，扩散对传质的贡献可忽略不计．     

锌原卟啉与儿童铅中毒和贫血关系的研究

[目的 ]探讨锌原卟啉测定诊断儿童铅中毒与贫血可能性。 [方法 ]测定了 2 3 5名儿童血ZPP、Hb、BPb。 [结果 ]ZPP值 2 3 9± 1 0 2 μg/gHb ,增高率 1 3 61 % ;血铅水平 8 94± 4 62 μg/dL ,铅中毒率 41 0 7%。Hb平均浓度 1 1 2 5 0± 1 0 5 5g/L ,贫血患病率 3 1 48%。ZPP与Hb呈高度负相关 (P <0 0 1 ) ,与BPb无相关性 (P >0 0 5 )。血铅水平正常组与铅中毒组ZPP值差异无显著意义(P >0 0 5 )。Hb正常组与贫血组ZPP值差异有显著意义 (P <0 0 1 )。 [结论 ]ZPP升高可作为缺铁性贫血的诊断指标 ,但在血铅水平较低的地区 ,则不宜用ZPP作为儿童铅中毒的筛查指标。     

Adsorptive stripping voltammetry of some trace elements in biological samples. I. Cadmium and zinc

A study of the adsorptive stripping voltammetry of cadmium and zinc is reported in which ligands containing sulphur donor atoms were examined. This type of ligand showed good adsorptive behaviour and strong metal complexation. It was found that the ligand 2,5-dimer-capto-1,3,4-thiadiazole (DMTD) was very suitable for the determination of cadmium and zinc using this technique.The method was applied to the direct determination of these metals in biological samples using benzyl trimethylammonium methoxide as digesting solvent for the samples.