E.coli酪氨酸转氨酶的纯化与非天然氨基酸的底物特异性检测

构建重组菌株E.coliBL21(DE3)转pET23a-tyrB,IPTG诱导其大量表达,然后依次通过盐析、离子交换层析、疏水层析、凝胶过滤层析获得纯酶,运用薄层层析技术(TLC)检测,结果表明纯化的TyrAT转氨酶对自身底物酪氨酸在37℃和50℃具有较高活性.分别加入非天然氨基酸L-正缬氨酸、L-新戊基甘氨酸、L-叔亮氨酸、D-正亮氨酸作为底物,检测到TyrAT转氨酶对L-叔亮氨酸在50℃下有活性,对D-正亮氨酸在37℃和50℃均有催化活性,且50℃下效果更好.     

管藻目绿藻叶绿素蛋白复合物PAGE分离方法的优化

以高等植物菠菜为对照，对管藻目绿藻刺松藻和假根羽藻叶绿素蛋白复合物的ＰＡＧＥ分离方法进行了优化。选择ＳＤＳ，ＤＯＣ，ＤＭＧ和ＴｒｉｔｏｎＸ－１００４种去污剂在不同的浓度、比例及增溶时间条件下，对色素蛋白复合物的分离效果进行了比较，并对电泳分离条件做了部分改进，提高了分辨率。     

采用蛋白酶组合漂白技术对羊毛增白的探讨

根据厂家对羊毛织物白度要求，需要开发一种快速，安全，价廉的羊毛漂白生产技术以满足于生产研究，研究了蛋白关正常氧漂工艺中对织物白度的促进作用及采取正确处理方法是获得良好的必要条件。     

The Janus kinase family of protein tyrosine kinases and their role in signaling

In the early 1990s, the search for protein kinases led to the discovery of a novel family of non-receptor tyrosine kinases, the Janus kinases or JAKs. These proteins were unusual because they contained two kinase homology domains and no other known signaling modules. It soon became clear that these were not ‘just another’ type of kinase. Their ability to complement mutant cells insensitive to interferons and to be activated by a variety of cytokines demonstrated their central signaling function. Now, as we approach the end of the decade, it is evident from biochemical studies to knockout mice that JAKs play non-redundant functions in development, differentiation, and host defense mechanisms. Here, recent progress is reviewed, with particular emphasis on structure-function studies aimed at revealing how this family of tyrosine kinases is regulated.     

Biological activity and pathological implications of misfolded proteins

The physiological metabolism of proteins guarantees that different cellular compartments contain the appropriate concentration of proteins to perform their biological functions and, after a variable period of wear and tear, mediates their natural catabolism. The equilibrium between protein synthesis and catabolism ensures an effective turnover, but hereditary or acquired abnormalities of protein structure can provoke a premature loss of biological function, an accelerated catabolism and diseases caused by the loss of an irreplaceable function. In certain proteins, abnormal structure and metabolism are associated with a strong tendency to self-aggregation into a polymeric fibrillar structure, and in these cases the disease is not principally caused by the loss of an irreplaceable function but by the action of this new biological entity. Amyloid fibrils are an apparently inert, insoluble, mainly extracellular protein polymer that kills the cell without tissue necrosis but by activation of the apoptotic mechanism. We analyzed the data reported so far on the structural and functional properties of four prototypic proteins with well-known biological functions (lysozyme, transthyretin, β2-microglobulin and apolipoprotein AI) that are able to create amyloid fibrils under certain conditions, with the perspective of evaluating whether the achievement of biological function favors or inhibits the process of fibril formation. Furthermore, studying the biological functions carried out by amyloid fibrils reveals new types of protein-protein interactions in the transmission of messages to cells and may provide new ideas for effective therapeutic strategies. Received 9 November 1998; received after revision 15 January 1999; accepted 15 January 1999     

固相碘标记活化珠标记蛋白质研究

作者报道了利用其合成的固相碘标记活化珠碘标记蛋白质的方法和效果.考察了各种标记条件活化珠用量及粒径,pH值,温度,标记时间,体积及蛋白质对标记率的影响.结果显示,用此活化珠,碘标记条件温和,标记效率高,标记物稳定且对标记蛋白的损伤小,适用范围大.因此具有良好的应用前景.     

Nicotinamide/nicotinic acid mononucleotide adenylyltransferase, new insights into an ancient enzyme

Nicotinamide/nicotinic acid mononucleotide adenylyltransferase (NMNAT) has long been known as the master enzyme in NAD biosynthesis in living organisms. A burst of investigations on NMNAT, going beyond enzymology, have paralleled increasing discoveries of key roles played by NAD homeostasis in a number or patho-physiological conditions. The availability of in-depth kinetics and structural enzymology analyses carried out on NMNATs from different organisms offer a powerful tool for uncovering fascinating evolutionary relationships. On the other hand, additional functions featuring NMNAT have emerged from investigations aimed at unraveling the molecular mechanisms responsible for complex biological phenomena such as neurodegeneration. NMNAT appears to be a multifunctional protein that sits both at the core of central metabolism and at a crossroads of multiple cellular processes. The resultant wealth of biochemical data has built a robust framework upon which design of NMNAT activators, inhibitors or enzyme variants of potential medical interest can be based.     

磁性琼酯糖亲和吸附剂的合成与应用

采用反相悬浮包埋技术合成了粒径在43-295μm之间的磁性琼脂糖微球。磁性琼脂糖微球经环氧氯丙烷活化后，分别键合6-氨基已酸、氨基乙酸和乙二胺为间隔臂，用水溶性碳二亚胺为缩合剂，分别偶联对氨基苯甲脒、l-精氨酸甲酯和胍基已酸，制备了3种磁性亲和吸附剂，并用于尿激酶粗品的分离纯化。测定了活性回收率和比活提高倍数，并与以磁性葡聚糖为基质的磁性亲和吸附剂对尿激酶的纯化效果进行了对比。     

For whom the bell tolls? DING proteins in health and disease

DING proteins, identified mainly by their eponymous N-terminal sequences, are ubiquitous in living organisms. Amongst bacteria, they are common in pseudomonads, and have been characterised with respect to genetics and structure. They form part of a wider family of phosphate-binding proteins, with emerging roles in phosphate acquisition and pathogenicity. Many DING proteins have been isolated in eukaryotes, in which they have been associated with very diverse biological activities, often in the context of possible signalling roles. Disease states in which DING proteins have been implicated include rheumatoid arthritis, lithiasis, atherosclerosis, some tumours and tumour-associated cachexia, and bacterial and viral adherence. Complete genetic and structural characterisation of eukaryotic DING genes and proteins is still lacking, though the phosphate-binding site seems to be conserved. Whether as bacterial proteins related to bacterial pathogenicity, or as eukaryotic components of biochemical signalling systems, DING proteins require further study. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

纳滤技术在制药业废碱回收中的应用研究

文中研究一种新型纳滤膜对大孔树脂再生废碱液的过滤纯化作用。工业废碱的碱含量为2％-3％，COD在5000-10000mg／L之间，透光度为10％以下。通过S-357纳滤膜，可回收用于树脂再生的稀碱液。稀碱液的碱含量为2％，COD在400mg／L以下，透光度接近100％。纳虑过滤过程通量稳定，简单的化学清洗可恢复通量。