Identification of ‘cystic fibrosis protein’ as a complex of two calcium-binding proteins present in human cells of myeloid origin

Cystic fibrosis protein is a serum protein characterized by a pI close to 8.4 and present with a higher concentration in serum and plasma of cystic fibrosis carriers than in controls. This protein was found immunologically indistinguishable from the cystic fibrosis antigen isolated from granulocytes and presenting a sequence analogous to that of MRP-8, a calcium-binding protein expressed in the myeloid cell lineage. Using antibodies directed against MRP-8 and its closely associated calcium-binding protein, MRP-14, we demonstrate here that cystic fibrosis protein purified from serum is a complex of the two proteins MRP-8 and MRP-14.     

The investigation of membrane binding by amphibian peptide agonists of CCK2R using 31P and 2H solid-state NMR

It has been proposed that some neuropeptides may be anchored to the cell membranes prior to attaching to the adjacent active sites of transmembrane receptors. The three amphibian skin neuropeptides signiferin 1 [RLCIPYIIPC(OH)] (smooth muscle active and immunomodulator), riparin 1.1 [[RLCIPVIFPC(OH)] (immunomodulator) and rothein 1 [SVSNIPESIGF(OH)] (immunomodulator) act via CCK2 transmembrane receptors. A combination of ³¹P and ²H solid state NMR studies of each of these three peptides in eukaryotic phospholipid models at 25 °C shows that rothein 1 does not interact with the membrane at all. In contrast, both of the cyclic disulfides signiferin 1 and riparin 1.1 interact with phospholipid head groups and partially penetrate into the upper leaflet of the model bilayer, but to different extents. These interactions are not sufficiently effective to cause disruption of the lipid bilayer since the peptides are not antimicrobial, anticancer, antifungal nor active against enveloped viruses.     

Saposin Lipid Nanoparticles: A Highly Versatile and Modular Tool for Membrane Protein Research

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Cyclic analogue of S-benzylisothiourea that suppresses kynurenine production without inhibiting indoleamine 2,3-dioxygenase activity

Kynurenine is biosynthesised from tryptophan catalysed by indoleamine 2,3-dioxygenase (IDO). The abrogation of kynurenine production is considered a promising therapeutic target for immunological cancer treatment. In the course of our IDO inhibitor programme, formal cyclisation of the isothiourea moiety of the IDO inhibitor 1 afforded the 5-Cl-benzimidazole derivative 2b-6, which inhibited both recombinant human IDO (rhIDO) activity and cellular kynurenine production. Further derivatisation of 2b-6 provided the potent inhibitor of cellular kynurenine production 2i (IC₅₀?=?0.34?µM), which unexpectedly exerted little effect on the enzymatic activity of rhIDO. Elucidation of the mechanism of action revealed that compound 2i suppresses IDO expression at the protein level by inhibiting STAT1 expression in IFN-γ-treated A431 cells. The kynurenine-production inhibitor 2i is expected to be a promising starting point for a novel approach to immunological cancer treatment.     

糖皮质激素联合吗替麦考酚酯分散片对系统性红斑狼疮患者的疗效及对免疫功能的影响

目的:研究糖皮质激素联合吗替麦考酚酯分散片治疗系统性红斑狼疮患者的临床疗效及对免疫功能的影响。方法:选取2014年9月至2015年8月本院收治的84例系统性红斑狼疮患者,根据投硬币法分为观察组和对照组,42例每组。对照组使用单纯的糖皮质激素,观察组在此基础上使用吗替麦考酚酯分散片。比较两组患者临床疗效,治疗前后免疫球蛋白A(IgA)、免疫球蛋白(IgG)、免疫球蛋白(IgM)、C反应蛋白(CRP)、血沉(ESR)的变化及不良反应的发生情况。结果:治疗后,观察组临床总有效率显著高于对照组(P0.05)。治疗前,两组患免疫球蛋白A(IgA)、免疫球蛋白(IgG)、免疫球蛋白(IgM)、C反应蛋白(CRP)、血沉(ESR)水平比较差异均无统计学意义(P0.05);治疗后,两组患者IgA、IgG、IgM、CRP、ESR水平均较治疗前显著降低(P0.05),与对照相比,观察组的IgA、IgG、IgM、CRP、ESR明显降低(P0.05)。两组组的不良反应率比较差异无统计学意义(P0.05)。结论:糖皮质激素联合吗替麦考酚酯分散片能有效改善系统性红斑狼疮患者的免疫功能,临床疗效良好,安全性高。     

Studies on the Reactivation of Aerated Nitrogenase MoFe Protein from Azotobacter vinelandii by the Compounds of iron Molybdenum and Sulfur

After the exposure to air, the crystalline nitrogenase MoFe protein from Azotobacter vinelandii was resulted in the remarkable increase in its absorption (ABS) and the significant decrease in its activity and circular dichroism (CD). However, when the aerated MoFe protein was incubated with the reconstituting solution which consisted of Na2MoO4, ferric citrate, Na2S and dithiothreitol, the ABS and CD of the aerated. MoFe protein both were completely restored, simultaneously with the significant restoration of acetylene reduction. It is shown that the P-cluster and other parts related to the protein activity which was damaged by O2 are able to be repaired to a certain extent by the reconstituting solution.     

Reconstitution of the plant ubiquitination cascade in bacteria using a synthetic biology approach

Ubiquitination modulates nearly all aspects of plant life. Here, we reconstituted the Arabidopsis thaliana ubiquitination cascade in Escherichia coli using a synthetic biology approach. In this system, plant proteins are expressed and then immediately participate in ubiquitination reactions within E. coli cells. Additionally, the purification of individual ubiquitination components prior to setting up the ubiquitination reactions is omitted. To establish the reconstituted system, we co‐expressed Arabidopsis ubiquitin (Ub) and ubiquitination substrates with E1, E2 and E3 enzymes in E. coli using the Duet expression vectors. The functionality of the system was evaluated by examining the auto‐ubiquitination of a RING (really interesting new gene)‐type E3 ligase AIP2 and the ubiquitination of its substrate ABI3. Our results demonstrated the fidelity and specificity of this system. In addition, we applied this system to assess a subset of Arabidopsis E2s in Ub chain formation using E2 conjugation assays. Affinity‐tagged Ub allowed efficient purification of Ub conjugates in milligram quantities. Consistent with previous reports, distinct roles of various E2s in Ub chain assembly were also observed in this bacterial system. Therefore, this reconstituted system has multiple advantages, and it can be used to screen for targets of E3 ligases or to study plant ubiquitination in detail.