蛋白质沉淀剂对棉铃虫谷胱甘肽S-转移酶的部分纯化

通过用聚乙烯亚胺（PEI）、硫酸铵、聚乙二醇（PEG）沉淀技术和GSH-Sepharose 4B亲和柱对棉铃虫Helicoverpa armigera (Hübner)幼虫中谷胱甘肽S-转移酶进行了部分纯化研究。结果表明PEG10000和PEG20000的纯化效果优于硫酸铵的沉淀效果。通过PEI沉淀去核酸后,再用硫酸铵沉淀,中肠和脂肪体GST活性分布在70%～75％和60%～65％沉淀段,比活力分别为1 081.49和596.41 nmol/(min·mg),纯化倍数分别为2.53和2.2。在6种PEG中,PEG10000和PEG20000的纯化效果较好。在中肠和脂肪体中PEG10000沉淀的GST活性峰分别在40%～45％和30%～40％,GST比活力分别为795.11和1 080.18 nmol/(min·mg),纯化倍数分别是2.4和3.97。PEG20000沉淀中肠和脂肪体GST的活性峰分别在25%～40％和25%～45％,比活力分别是767.57和945.96 nmol/(min·mg),纯化倍数分别是2.81和3.05。用GSH-Sepharose 4B纯化中肠GST,GST比活力达到5 888.44 nmol/(min·mg),纯化倍数达到107.38。     

Characterization of a thy1.2 GFP transgenic mouse reveals a tissue-specific organization of the spinal dorsal horn

In this study, transgenic mice in which membrane-linked enhanced green fluorescent protein (mGFP) is expressed from the Thy1.2 promoter were used. In these mice, a subpopulation of small to medium sized DRG neurons double stained for IB4 but not for CGRP. Most of the peripheral terminals traversed the dermis and ramify within the epidermis and form superficial terminals. Within the spinal cord, these afferents terminated exclusively within the substantia gelatinosa (SG). A second fibre type in the skin also expressed mGFP, and formed club-shaped endings towards the bases of hairs. Injury to the sciatic nerve resulted in mGFP loss from the SG ipsilateral to the nerve injury, but also in the corresponding region contralaterally. Together, these findings reveal the specificity of connectivity of a defined subpopulation of DRG sensory neurons innervating the epidermis and this will facilitate analysis of their physiological functions.     

Role of nuclear receptor corepressor RIP140 in metabolic syndrome

Obesity and its associated complications, which can lead to the development of metabolic syndrome, are a worldwide major public health concern especially in developed countries where they have a very high prevalence. RIP140 is a nuclear coregulator with a pivotal role in controlling lipid and glucose metabolism. Genetically manipulated mice devoid of RIP140 are lean with increased oxygen consumption and are resistant to high-fat diet-induced obesity and hepatic steatosis with improved insulin sensitivity. Moreover, white adipocytes with targeted disruption of RIP140 express genes characteristic of brown fat including CIDEA and UCP1 while skeletal muscles show a shift in fibre type composition enriched in more oxidative fibres. Thus, RIP140 is a potential therapeutic target in metabolic disorders. In this article we will review the role of RIP140 in tissues relevant to the appearance and progression of the metabolic syndrome and discuss how the manipulation of RIP140 levels or activity might represent a therapeutic approach to combat obesity and associated metabolic disorders. This article is part of a Special Issue entitled: Translating nuclear receptors from health to disease.     

Structure-based design of selective phosphodiesterase 4B inhibitors based on ginger phenolic compounds

Phosphodiesterase 4 (PDE4) has been established as a drug target for inflammatory diseases of respiratory tract like asthma and chronic obstructive pulmonary disease. The selective inhibitors of PDE4B, a subtype of PDE4, are devoid of adverse effects like nausea and vomiting commonly associated with non-selective PDE4B inhibitors. This makes the development of PDE4B subtype selective inhibitors a desirable research goal. Thus, in the present study, molecular docking, molecular dynamic simulations and binding free energy were performed to explore potential selective PDE4B inhibitors based on ginger phenolic compounds. The results of docking studies indicate that some of the ginger phenolic compounds demonstrate higher selective PDE4B inhibition than existing selective PDE4B inhibitors. Additionally, 6-gingerol showed the highest PDE4B inhibitory activity as well as selectivity. The comparison of binding mode of PDE4B/6-gingerol and PDE4D/6-gingerol complexes revealed that 6-gingerol formed additional hydrogen bond and hydrophobic interactions with active site and control region 3 (CR3) residues in PDE4B, which were primarily responsible for its PDE4B selectivity. The results of binding free energy demonstrated that electrostatic energy is the primary factor in elucidating the mechanism of PDE4B inhibition by 6-gingerol. Dynamic cross-correlation studies also supported the results of docking and molecular dynamics simulation. Finally, a small library of molecules were designed based on the identified structural features, majority of designed molecules showed higher PDE4B selectivity than 6-gingerol. These results provide important structural features for designing new selective PDE4B inhibitors as anti-inflammatory drugs and promising candidates for synthesis and pre-clinical pharmacological investigations.     

Ultrastructural and hormonal changes in rat cauda epididymal spermatozoa induced by Boswellia papyrifera and Boswellia carterii

Boswellia papyrifera and Boswellia carterii diffuses smoke polluting air that adversely affects indoor environment that certainly harm human health. Therefore, this study aims at ascertaining the effect of these plants on gonadal hormones and molecular changes in rat spermatozoa. The animals were exposed to 4 g/kg body weight of B. papyrifera and B. carterii daily for 120 days along with suitable controls. Significant decreases in FSH, LH and testosterone levels were evidenced, along with a reduction of protein, sialic acid, and carnitine levels. In sperm physiology, sperm count, motility, speed decrease, whereas sperm anomalies increase. TEM observation indicates morphological changes in plasma and acrosomal membranes, cytoplasmic droplet in the tail region, vacuolated, and disorganization of the mitochondrial sheath. These findings demonstrate that B. papyrifera and B. carterii smoke affects the process of sperm formation and maturation, which indicates the detrimental effects of these plants on the reproductive system.     

转基因烟草生产霍乱毒素B亚单位的纯化

提取转基因烟草叶片总蛋白,用经溴化氰活化的Ｓｅｐｈａｒｏｓｅ ４Ｂ偶联有抗ＣＴ ＩｇＧ色谱柱,得到了表达产物ＣＴＢ蛋白质。经ＰＡＧＥ、Ｗｅｓｔｅｒｎ ｂｌｏｔ、琼脂糖免疫扩散和免疫电泳等方法鉴定表明该蛋白与天然ＣＴＢ相同。     

Production of antimicrobial substances by Bacillus subtilis LFE-1, B. firmus HO-1 and B. licheniformis T6-5 isolated from an oil reservoir in Brazil

AIMS: Forty Bacillus strains isolated from a Brazilian oil reservoir were tested against each other to select strains producing antimicrobial substances (AMS). Three strains, Bacillus subtilis (LFE-1), Bacillus firmus (H2O-1) and Bacillus licheniformis (T6-5), were selected due to their ability to inhibit more than 65% of the Bacillus strains tested. These three strains were also investigated for their capability to inhibit sulphate-reducing bacteria (SRB). Furthermore, physiological and biochemical characteristics of the antimicrobial compounds produced by the selected strains were determined. METHODS AND RESULTS: Among the forty strains tested, 36 (90%) strains were able to inhibit at least one Bacillus strain used as indicator in plate assays and three of them (LFE-1, T6-5 and H2O-1) were able to inhibit 65, 70 and 97.5% of the 40 strains studied here respectively. Clear zones of inhibition were observed when H2O-1 was tested against SRB-containing consortium T6-lab and Desulfovibrio alaskensis strain NCIMB 13491, while strain T6-5 was able to inhibit only the D. alaskensis strain. The three substances showed to be insensitive to different enzymes and chemicals, were heat stable and the substances produced by strains T6-5 and H2O-1 were active over a wide pH range. CONCLUSIONS: Three different AMS produced by Bacillus strains from an oil reservoir, two of them with activity against SRB, are presented here. SIGNIFICANCE AND IMPACT OF THE STUDY: The preliminary characterization of these AMS points to their potential use as biocides in the petroleum industry for controlling problems associated with SRB.