http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Park, Dongkook,Shafer, Orie T.,Shepherd, Stacie P.,Suh, Hyunsuk,Trigg, Jennifer S.,Taghert, Paul H. American Society for Microbiology 2008 Molecular and cellular biology Vol.28 No.1
<B>ABSTRACT</B><P>The basic helix-loop-helix (bHLH) protein DIMMED (DIMM) supports the differentiation of secretory properties in numerous peptidergic cells of <I>Drosophila melanogaster</I>. DIMM is coexpressed with diverse amidated neuropeptides and with the amidating enzyme peptidylglycine α-hydroxylating monooxygenase (PHM) in approximately 300 cells of the late embryo. Here we confirm that DIMM has transcription factor activity in transfected HEK 293 cells and that the <I>PHM</I> gene is a direct target. The mammalian DIMM orthologue MIST1 also transactivated the <I>PHM</I> gene. DIMM activity was dependent on the basic region of the protein and on the sequences of three E-box sites within <I>PHM</I>'s first intron; the sites make different contributions to the total activity. These data suggest a model whereby the three E boxes interact cooperatively and independently to produce high <I>PHM</I> transcriptional activation. This DIMM-controlled <I>PHM</I> regulatory region displayed similar properties in vivo. Spatially, its expression mirrored that of the DIMM protein, and its activity was largely dependent on <I>dimm</I>. Further, in vivo expression was highly dependent on the sequences of the same three E boxes. This study supports the hypothesis that DIMM is a master regulator of a peptidergic cell fate in <I>Drosophila</I> and provides a detailed transcriptional mechanism of DIMM action on a defined target gene.</P>
^1H-NMR studies on d(GCTTAAGC)_2 and its complex with berenil
HU, Sungho,WEISZ, Klaus,JAMES, Thomas L.,SHAFER, Richard H. 충남대학교 생물공학연구소 1993 생물공학연구지 Vol.3 No.-
Two-dimensional (2D) ^1H-NMR spectroscopy has been used analyze the structure of d(GCTTAAGC)_2 and its interaction with berenil in solution. Nuclear Overhauser enhancement connectivities enabled sequential assignments of nearly all proton resonances in the self-complementary octamer duplex and demonstrated that the oligonucleotide is primarily in a B-type conformation. No major conformational changes were observed by the addition of berenil, but proton resonances of the two adenosine nucleotides shifted substantially. Intermolecular nuclear Overhauser effects between berenil and the DNA duplex revealed that the drug binds via the minor groove of d(GCTTAAGC)_2 in the A.T-base-pair region. At 18℃ the twofold symmetry of the duplex is preserved on berenil binding .However, strongly shifted proton resonances broadened significantly. A model is proposed for the berenil-d(GCTTAAGC)_2 complex involving fast exchange of berenil between two equivalent symmetry-related binding sites, which span the 5'-TAA-3' region and are asymmetrically disposed with respect to the dyad axis of the duplex. These results are compared with previous studies on the berenil-d(GCAATTGC)_2 complex.
Heo, Jongbae,Antkiewicz, Dagmara S,Shafer, Martin M,Perkins, Dawn A K,Sioutas, Constantinos,Schauer, James J Springer-Verlag 2015 Analytical and bioanalytical chemistry Vol.407 No.20
<P>In order to further our understanding of the influence of chemical components and ultimately specific sources of atmospheric particulate matter (PM) on pro-inflammatory and other adverse cellular responses, we promulgate and apply a suite of chemical fractionation tools to aqueous aerosol extracts of PM samples for analysis in toxicity assays. We illustrate the approach with a study that used water extracts of quasi-ultrafine PM (PM0.25) collected in the Los Angeles Basin. Filtered PM extracts were fractionated using Chelex, a weak anion exchanger diethylaminoethyl (DEAE), a strong anion exchanger (SAX), and a hydrophobic C18 resin, as well as by desferrioxamine (DFO) complexation that binds iron. The fractionated extracts were then analyzed using high-resolution sector field inductively coupled plasma mass spectrometry (SF-ICPMS) to determine elemental composition. Cellular responses to the fractionated extracts were probed in an in vitro rat alveolar macrophages model with measurement of reactive oxygen species (ROS) production and the cytokine tumor necrosis factor-α (TNF-α). The DFO treatment that chelates iron was very effective at reducing the cellular ROS activity but had only a small impact on the TNF-α production. In contrast, the hydrophobic C18 resin treatment had a small impact on the cellular ROS activity but significantly reduced the TNF-α production. The use of statistical methods to integrate the results across all treatments led to the conclusion that sufficient iron must be present to participate in the chemistry needed for ROS activity, but the amount of ROS activity is not proportional to the iron solution concentration. ROS activity was found to be most related to cationic mono- and divalent metals (i.e., Mn and Ni) and oxyanions (i.e., Mo and V). Although the TNF-α production was not significantly affected by the chelexation of iron, it was greatly impacted by the removal of organics with the C18 resin and all other metal removal methods, suggesting that iron is not a critical pathway leading to TNF-α production, but a wide range of soluble metals and organic compounds in particulate matter play a role. Although the results are specific to the Los Angeles Basin, where the samples used in the study were collected, the method employed in the study can be widely employed to study the role of components of particulate matter in in vitro or in vivo assays.</P>
Miyasaki, Kenneth T.,Bodeau, Amy L.,Pohl, Jan,Shafer, William M. Korean Academy of Oral Biology and the UCLA Dental 1997 International Journal of Oral Biology Vol.22 No.3
Human neutrophil cathepsin G possesses a number of antibiotic peptide domains and is known to kill periodontopathic bacteria by two different mechanisms: the first requiring an intact enzyme site, and the second which does not. Here, we investigate whether intact enzyme site-dependency correlates with differential selectivities of the antibiotic peptide domains of cathepsin G. Peptide segments of cathepsin G (about 20 amino acids per peptide) were synthesized using the Merrifield solid phase technique and designated CG01-20, CG21-40, CG41-60, CG61-80, CG77-96, CG97-116, CG117-136, CG137-156, CG157-176, CG177-197, and CG198-223. Strains of Capnocytophaga spp., organisms killed only by the first mechanism, exhibited sensitivity to CG117-136, and CG198-223, mainly; and variable sensitivity to CG01-20 and CG01-80. In comparison, strains of A.actionomycetcomitans, organisms killed by the second mechanism, exhibited sensitivity to CG61-80, CG117-136, and CG198-223; and variable sensitivity to CG01-20, CG97-116, CG137-156, and CG157-176. These results show that segments of cathepsin G differentially killed two periodontal bacteria, and suggests that the two distinct killing mechanisms correlate with these domain sensitivities.