Biochemical characterization of a CDC6-like protein from the crenarchaeon Sulfolobus solfataricus

Cdc6 proteins play an essential role in the initiation of chromosomal DNA replication in Eukarya. Genes coding for putative homologs of Cdc6 have been also identified in the genomic sequence of Archaea, but the properties of the corresponding proteins have been poorly investigated so far. Herein, we report the biochemical characterization of one of the three putative Cdc6-like factors from the hyperthermophilic crenarchaeon Sulfolobus solfataricus (SsoCdc6-1). SsoCdc6-1 was overproduced in Escherichia coli as a His-tagged protein and purified to homogeneity. Gel filtration and glycerol gradient ultracentrifugation experiments indicated that this protein behaves as a monomer in solution (molecular mass of about 45 kDa). We demonstrated that SsoCdc6-1 binds single- and double-stranded DNA molecules by electrophoretic mobility shift assays. SsoCdc6-1 undergoes autophosphorylation in vitro and possesses a weak ATPase activity, whereas the protein with a mutation in the Walker A motif (Lys-59 --> Ala) is completely unable to hydrolyze ATP and does not autophosphorylate. We found that SsoCdc6-1 strongly inhibits the ATPase and DNA helicase activity of the S. solfataricus MCM protein. These findings provide the first in vitro biochemical evidence of a functional interaction between a MCM complex and a Cdc6 factor and have important implications for the understanding of the Cdc6 biological function.     

Indole derivatives as dual-effective agents for the treatment of neurodegenerative diseases: Synthesis,biological evaluation,and molecular modeling studies

Several indole derivatives, that were highly potent ligands of GluN2B-subunit-containing N-methyl-d-aspartate (NMDA) receptor, also demonstrated antioxidant properties in ABTS method. In particular, the 2-(4-benzylpiperidin-1-yl)-1-(5-hydroxy-1H-indol-3-yl)ethanone (1) proved to be a dual-effective neuroprotective agent. With the aim to increase the antioxidant properties we added a catechol moiety onto piperidine moiety. The designed hybrid derivative 3,4-dihydroxy-N-[1-[2-(5-hydroxy-1H-indol-3-yl)-2-oxoethyl]piperidin-4-yl]benzamide (10) was the most effective antioxidant agent (>94.1 ± 0.1% of inhibition at 17 μM) and showed GluN2B/NMDA receptor affinity at low micromolar concentration (IC₅₀ 0.66 μM). By means of computational studies we explored the effect of the presence of this antioxidant fragment during the recognition process to binding pocket.     

Coralloid root regeneration on Macrozamia megagametophites

Abstract

Megagametophytes of Macrozamia communis were incubated in White's Basal Medium and in White's Basal Medium modified with 2,4-D and kinetin. On the medium enriched with growth substances, regeneration of coralloid roots was induced. These are morphologically identical to sporophytic coralloid roots, without any endosymbiont and displaying negative geotropism. These results confirm the fact that coralloid roots represent an inherent feature of the root system of the Cycadales rather than being the result of induction by microbial factors. Therefore it is possible to suggest that coralloid roots represent vestigial pneumatophores.     

滞育及不同虫态下亚洲玉米螟内参基因的筛选

筛选出滞育状态下以及不同虫态下亚洲玉米螟Ostrinia furnacalis(Guenée)的实时荧光定量PCR(RT-qPCR)最稳定内参基因,本结果为研究不同虫态及滞育1个月,滞育2个月,滞育3个月和滞育4个月的亚洲玉米螟目的基因表达水平提供参考依据。本文以不同虫态及滞育状态下的亚洲玉米螟为试验材料,应用RT-qPCR技术检测β-actin,18S rRNA,EF1-α和RPS3共4个候选内参基因的表达稳定性水平,结合ge Norm,Normfinder,Best Keeper和Ref Finder软件分析各候选内参基因在不同处理下的表达稳定性。结果表明,在亚洲玉米螟不同虫态中,4个候选内参基因的稳定性大小排序为18S rRNAEF1-αβ-actinRPS3;滞育1个月,滞育2个月,滞育3个月和滞育4个月的亚洲玉米螟,稳定性大小排序为β-actinEF1-α18S rRNARPS3。18S rRNA和β-actin可分别作为不同虫态和滞育状态下的亚洲玉米螟基因表达水平分析试验中的内参基因。     

Proteome analysis of bronchoalveolar lavage in lung diseases

The proteomic approach is complementary to genomics and enables protein composition to be investigated under various clinical conditions. Its application to the study of bronchoalveolar lavage (BAL) is extremely promising. BAL proteomic studies were initially based on two-dimensional electrophoretic separation of complex protein samples and subsequent identification of proteins by different methods. With the techniques available today it is possible to attain many different research objectives. BAL proteomics can contribute to the identification of proteins in alveolar spaces with possible insights into pathogenesis and clinical application for diagnosis, prognosis and therapy. Many proteins with different functions have already been identified in BAL. Some could be biomarkers that need to be individually confirmed by correlation with clinical parameters and validation by other methods on larger cohorts of patients. The standardization of BAL sample preparation and processing for proteomic studies is an important goal that would promote and facilitate clinical applications. Here, we review the principal literature on BAL proteomic analysis applied to the study of lung diseases.