Two-photon Photo-emission of Ultrathin Film PTCDA Morphologies on Ag(111)

Morphology- and layer-dependent electronic structure and dynamics at the PTCDA/Ag(111) interface have been studied with angle-resolved two-photon photoemission. In Stranski-Krastanov growth modes, the exposed wetting layer inhibited the evolution of the vacuum level and valence band to bulk values. For layer-by-layer growth, we observed the transition of electron structure from monolayer to bulk values within eight monolayers. Effective masses and lifetimes of the conduction band and the n=1 image potential state were measured to be larger for disordered layers. The effective mass was interpreted in the context of charge mobility measurements

Proteomic and Systems Biology Analysis of Monocytes Exposed to Securinine, a GABA_A Receptor Antagonist and Immune Adjuvant

<div><p>Securinine, a GABA_A receptor antagonist, has been reported to enhance monocyte cell killing of <em>Coxiella burnetii</em> without obvious adverse effects <em>in vivo</em>. We employed multiplex 2D gel electrophoresis using Zdyes, a new generation of covalently linked fluorescent differential protein detection dyes to analyze changes in the monocyte proteome in response to Securinine. Securinine antagonism of GABA_A receptors triggers the activation of p38. We used the differential protein expression results to guide a search of the literature and network analysis software to construct a systems biology model of the effect of Securinine on monocytes. The model suggests that various metabolic modulators (fatty acid binding protein 5, inosine 5′-monophosphate dehydrogenase, and thioredoxin) are at least partially reshaping the metabolic landscape within the monocytes. The actin bundling protein L-plastin, and the Ca²⁺ binding protein S100A4 also appear to have important roles in the immune response stimulated by Securinine. Fatty acid binding protein 5 (FABP5) may be involved in effecting lipid raft composition, inflammation, and hormonal regulation of monocytes, and the model suggests that FABP5 may be a central regulator of metabolism in activated monocytes. The model also suggests that the heat shock proteins have a significant impact on the monocyte immune response. The model provides a framework to guide future investigations into the mechanisms of Securinine action and with elaboration may help guide development of new types of immune adjuvants.</p> </div

Proteomic and Systems Biology Analysis of the Monocyte Response to <i>Coxiella burnetii</i> Infection

<div><p><i>Coxiella burnetii</i> is an obligate intracellular bacterial pathogen and the causative agent of Q fever. Chronic Q fever can produce debilitating fatigue and <i>C. burnetii</i> is considered a significant bioterror threat. <i>C. burnetii</i> occupies the monocyte phagolysosome and although prior work has explained features of the host-pathogen interaction, many aspects are still poorly understood. We have conducted a proteomic investigation of human Monomac I cells infected with the Nine Mile Phase II strain of <i>C. burnetii</i> and used the results as a framework for a systems biology model of the host response. Our principal methodology was multiplex differential 2D gel electrophoresis using ZDyes, a new generation of covalently linked fluorescent protein detection dyes under development at Montana State University. The 2D gel analysis facilitated the detection of changes in posttranslational modifications on intact proteins in response to infection. The systems model created from our data a framework for the design of experiments to seek a deeper understanding of the host-pathogen interactions.</p></div

Structure Determination of Strawberry Aldehyde by Broadband Microwave Spectroscopy: Conformational Stabilization by Dispersive Interactions

The rotational spectrum of ethyl 3-methyl-3-phenylglycidate (C₁₂H₁₄O₃, strawberry aldehyde) has been obtained with chirped-pulse Fourier transform microwave spectroscopy. The sample is a mixture of diastereomers, cis and trans, with different relative stereochemistry around the central epoxide. The spectra of five conformers of this molecule (two of cis and three of trans) have been assigned, and carbon backbone structures for the two most populated conformers (one of cis and one of trans) were determined from ¹³C isotopomers in natural abundance using the Kraitchman relations. Comparisons of experimentally determined structural data to ab initio calculations show that the B3LYP density functional fails to account adequately for a long-range dispersive interaction between the phenyl ring and the terminal ethyl group in <i>cis</i>-strawberry aldehyde. However, calculations performed using both MP2 and the M05-2X density functional are able to capture the effects of this interaction on the molecular geometry

Schematic of antigen processing and presentation pathway for Hsp70 and Hsp90 generated by DAVID.

<p>DAVID utilized the KEGG pathways to diagram the role of Hsp70 and Hsp90 for antigen processing and presentation. Both Hsp70 and Hsp90 (red stars) are involved in MHC class I antigen processing. Hsp60 (not shown) is involved in MHC class II processing. The proteins and pathways proposed are in agreement with our manual search of the literature, which suggested that Hsps are involved in antigen presentation.</p

DAVID analysis of the linkages of transaldolase 1 (TAL1).

<p>Diagram from the KEGG pathway analysis database produced by DAVID⁶¹. The red star indicates TAL1 (EC 2.2.1.2). The diagram shows the involvement of transaldolase 1 in the pentose phosphate pathway.</p