Discovery of 3-hydroxy-4-cyano-isoquinolines as novel, potent, and selective inhibitors of human 11β-hydroxydehydrogenase 1 (11β-HSD1)

Derived from the HTS hit 1, a series of hydroxyisoquinolines was discovered as potent and selective 11β-HSD1 inhibitors with good cross species activity. Optimization of substituents at the 1 and 4 positions of the isoquinoline group in addition to the core modifications, with a special focus on enhancing metabolic stability and aqueous solubility, resulted in the identification of several compounds as potent advanced leads.     

Integration of protein motions with molecular networks reveals different mechanisms for permanent and transient interactions

The integration of molecular networks with other types of data, such as changing levels of gene expression or protein-structural features, can provide richer information about interactions than the simple node-and-edge representations commonly used in the network community. For example, the mapping of 3D-structural data onto networks enables classification of proteins into singlish- or multi-interface hubs (depending on whether they have >2 interfaces). Similarly, interactions can be classified as permanent or transient, depending on whether their interface is used by only one or by multiple partners. Here, we incorporate an additional dimension into molecular networks: dynamic conformational changes. We parse the entire PDB structural databank for alternate conformations of proteins and map these onto the protein interaction network, to compile a first version of the Dynamic Structural Interaction Network (DynaSIN). We make this network available as a readily downloadable resource file, and we then use it to address a variety of downstream questions. In particular, we show that multi-interface hubs display a greater degree of conformational change than do singlish-interface ones; thus, they show more plasticity which perhaps enables them to utilize more interfaces for interactions. We also find that transient associations involve smaller conformational changes than permanent ones. Although this may appear counterintuitive, it is understandable in the following framework: as proteins involved in transient interactions shuttle between interchangeable associations, they interact with domains that are similar to each other and so do not require drastic structural changes for their activity. We provide evidence for this hypothesis through showing that interfaces involved in transient interactions bind fewer classes of domains than those in a control set.     

Highly Efficient Flexible Hybrid Nanocrystal‐Cu(In,Ga)Se2 (CIGS) Solar Cells

A novel scheme for hybridizing inkjet‐printed thin film Cu(In,Ga)Se₂ (CIGS) solar cells with self‐assembled clusters of nanocrystal quantum dots (NQDs), which provides a 10.9% relative enhancement of the photon conversion efficiency (PCE), is demonstrated. A non‐uniform layer of NQD aggregates is deposited between the transparent conductive oxide and a CdS/CIGS p‐n junction using low cost pulsed‐spray deposition. Hybridization significantly improves the external quantum efficiency of the hybrid devices in the absorption range of the NQDs and in the red to near‐IR parts of the spectrum. The low wavelength response enhancement is found to be induced by luminescent down‐shifting (LDS) from the NQD layer, while the increase at longer wavelengths is attributed to internal scattering from NQD aggregates. LDS is demonstrated using time‐resolved spectroscopy, and the morphology of the NQD layer is investigated in fluorescence microscopy and cross‐sectional transmission electron microscopy. The influence of the NQD dose on the PCE of the hybrid devices is investigated and an optimum value is obtained. The low costs and limited material consumptions associated with pulsed‐spray deposition make these flexible hybrid devices promising candidates to help push thin‐film photovoltaic technology towards grid parity.     

Cellular Proteins Required for Adeno-Associated Virus DNA Replication in the Absence of Adenovirus Coinfection

We previously reported the development of an in vitro adeno-associated virus (AAV) DNA replication system. The system required one of the p5 Rep proteins encoded by AAV (either Rep78 or Rep68) and a crude adenovirus (Ad)-infected HeLa cell cytoplasmic extract to catalyze origin of replication-dependent AAV DNA replication. However, in addition to fully permissive DNA replication, which occurs in the presence of Ad, AAV is also capable of partially permissive DNA replication in the absence of the helper virus in cells that have been treated with genotoxic agents. Limited DNA replication also occurs in the absence of Ad during the process of establishing a latent infection. In an attempt to isolate uninfected extracts that would support AAV DNA replication, we discovered that HeLa cell extracts grown to high density can occasionally display as much in vitro replication activity as Ad-infected extracts. This finding confirmed previous genetic analyses which suggested that no Ad-encoded proteins were absolutely essential for AAV DNA replication and that the uninfected extracts should be useful for studying the differences between helper-dependent and helper-independent AAV DNA replication. Using specific chemical inhibitors and monoclonal antibodies, as well as the fractionation of uninfected HeLa extracts, we identified several of the cellular enzymes involved in AAV DNA replication. They were the single-stranded DNA binding protein, replication protein A (RFA), the 3′ primer binding complex, replication factor C (RFC), and proliferating cell nuclear antigen (PCNA). Consistent with the current model for AAV DNA replication, which requires only leading-strand DNA synthesis, we found no requirement for DNA polymerase α-primase. AAV DNA replication could be reconstituted with purified Rep78, RPA, RFC, and PCNA and a phosphocellulose chromatography fraction (IIA) that contained DNA polymerase activity. As both RFC and PCNA are known to be accessory proteins for polymerase δ and , we attempted to reconstitute AAV DNA replication by substituting either purified polymerase δ or polymerase for fraction IIA. These attempts were unsuccessful and suggested that some novel cellular protein or modification was required for AAV DNA replication that had not been previously identified. Finally, we also further characterized the in vitro DNA replication assay and demonstrated by two-dimensional (2D) gel electrophoresis that all of the intermediates commonly seen in vivo are generated in the in vitro system. The only difference was an accumulation of single-stranded DNA in vivo that was not seen in vitro. The 2D data also suggested that although both Rep78 and Rep68 can generate dimeric intermediates in vitro, Rep68 is more efficient in processing dimers to monomer duplex DNA. Regardless of the Rep that was used in vitro, we found evidence of an interaction between the elongation complex and the terminal repeats. Nicking at the terminal repeats of a replicating molecule appeared to be inhibited until after elongation was complete.     

体内精原干细胞转染法建立转基因小鼠

将人Bcl-2 cDNA与小鼠乳清酸蛋白(WAP)5’上游调控序列融合后,与脂质体按一定比例混合,再加入适量的台盼蓝制成转染液,注入到小鼠睾丸中的曲细精管中,转染精原干细胞以探讨建立转基因小鼠的可行性。共注射了3只公鼠,4天后将公鼠与发情母鼠合笼交配,共生仔鼠20只。检测结果表明,有3只呈PCR阳性,Southern blot检测,阳性鼠2只,1只公鼠,1只母鼠,其中,公鼠意外死亡;Western blot证实,1只母鼠的乳腺组织表达了Bcl-2蛋白,其F1代的16只小鼠中,有7只呈PCR阳性。证实了体内精原干细胞转染建立转基因动物的可行性。     

玫瑰花红色素及其稳定性研究

以玫瑰花色素作为新型天然食用色素的可行性进行了初步研究。对光、温度、ｐＨ值、氧化介质、还原介质、蔗糖、咸味（ＮａＣｌ）、铝制品（ＦｅＣｌ３）、铜制品（ＣｕＣｌ２）、锡制品（ＳｎＣｌ２）等对色素的稳定性影响,进行了初步探讨。结果表明,该色素对光、热耐受性好;适用ｐＨ值范围宽;耐氧化性较差,耐还原性较好;Ｆｅ＾３＋和Ｓｎ＾２＋对其吸光值有明显影响,Ｃｕ＾２＋、Ａｌ＾３＋、食盐和蔗糖则影响甚微。