Physical Sciences and Mathematics Commons^™

Viral Infection Causes A Shift In The Self Peptide Repertoire Presented By Human Mhc Class I Molecules, Charles T. Spencer, Jelena S. Bezbradica, Mireya G. Ramos, Chenoa D. Arico, Stephanie B. Conant, Pavlo Gilchuk, Jennifer J. Gray, Mu Zheng, Xinnan Niu, William Hildebrand, Andrew J. Link, Sebastian Joyce

Chemistry Faculty Research

Purpose

MHC class I presentation of peptides allows T cells to survey the cytoplasmic protein milieu of host cells. During infection, presentation of self peptides is, in part, replaced by presentation of microbial peptides. However, little is known about the self peptides presented during infection, despite the fact that microbial infections alter host cell gene expression patterns and protein metabolism.

Experimental design

The self peptide repertoire presented by HLA-A*01;01, HLA-A*02;01, HLA-B*07;02, HLA-B*35;01, and HLA-B*45;01 (where HLA is human leukocyte antigen) was determined by tandem MS before and after vaccinia virus infection.

Results

We observed a profound alteration in the self …

Effect Of Quercetin, Genistein And Kaempferol On Glutathione And Glutathione-Redox Cycle Enzymes In 3t3-L1 Preadipocytes, William Y. Boadi, Paul K. Amartey, Andrew Lo

Chemistry Faculty Research

Context and objective: Many studies have shown that cellular redox potential is largely determined by glutathione (GSH), which accounts for more than 90% of cellular nonprotein thiols. The aim of this study was to delineate the effect of three flavonoids – namely, quercetin, kaempferol and genistein – and exogenous GSH on oxidative damage by the Fenton’s pathway through the GSH and GSH-redox cycle enzymes in 3T3-L1 cells. Materials and methods: 3T3-L1 preadipocytes were exposed to each flavonoid and GSH at concentrations of 0, 5, 10, 15, 20 and 25 µM and then GSH levels and activities of glutathione peroxidase (GSH-Px), …

Synthesis Of Β-Triphosphotriester Pronucleotides, Yousef Beni, Chandravanu Dash, Keykavous Parang

Chemistry Faculty Research

Dinucleoside phosphorochloridite was synthesized from phosphorus trichloride and three nucleoside analogs, 3′-fluoro-2′,3′-dideoxythymidine (FLT), 2′,3′-dideoxy-5-fluoro-3′-thiacytidine (FTC), and 2′,3′-dideoxy-3′-thiacytidine (3TC), in a multistep synthesis. Polymer-bound N-Boc p-acetoxybenzyl 5′-O-2′-deoxythymidine was reacted with dinucleoside phosphorochloridite in the presence of 2,6-lutidine, followed by the reaction with dodecyl alcohol and 5-(ethylthio)-1H-tetrazole, oxidation with tert-butyl hydroperoxide, and acidic cleavage, respectively, to afford the β-triphosphotriester derivatives containing three different nucleosides.

Violacein Induces P44/42 Mitogen-Activated Protein Kinase‑Mediated Solid Tumor Cell Death And Inhibits Tumor Cell Migration, Toral Mehta, Koen P. Vercruysse, Terrance Johnson, Anthony Okechukwu Ejiofor, Elbert Myles, Quincy A. Quick

Chemistry Faculty Research

Microbial secondary metabolites have emerged as alternative novel drugs for the treatment of human cancers. Violacein, a purple pigment produced by Chromobacterium violaceum, was investigated in the present study for its anti‑tumor properties in tumor cell lines. Clinically applicable concentrations of violacein were demonstrated to inhibit the proliferative capacity of tumor cell lines according to a crystal violet proliferation assay. The underlying mechanism was the promotion of apoptotic cell death, as indicated by poly(ADP ribose) polymerase cleavage and p44/42 mitogen‑activated protein kinase signaling determined by western blot analysis. Collectively, this provided mechanistic evidence that violacein elicits extracellular-signal regulated kinase‑induced apoptosis …

Sequence-Specific, Nanomolar Peptide Binding Via Cucurbit[8]Uril-Induced Folding And Inclusion Of Neighboring Side Chains, Lauren C. Smith, David G. Leach, Brittney E. Blaylock, Omar A. Ali, Adam R. Urbach

Chemistry Faculty Research

This paper describes the molecular recognition of the tripeptide Tyr-Leu-Ala by the synthetic receptor cucurbit[8]uril (Q8) in aqueous buffer with nanomolar affinity and exceptional specificity. This combination of characteristics, which also applies to antibodies, is desirable for applications in biochemistry and biotechnology but has eluded supramolecular chemists for decades. Building on prior knowledge that Q8 binds to peptides with N-terminal aromatic residues, a library screen of 105 peptides was designed to test the effects of residues adjacent to N-terminal Trp, Phe, or Tyr. The screen used tetramethylbenzobis(imidazolium) (MBBI) as a fluorescent indicator and resulted in the unexpected discovery that MBBI …

Impact Of Size, Secondary Structure, And Counterions On The Binding Of Small Ribonucleic Acids To Layered Double Hydroxide Nanoparticles, B. V. Rodriguez, J. Pescador, N. Pollok, G. W. Beall, Corina Maeder, L. K. Lewis

Chemistry Faculty Research

Use of ribonucleic acid (RNA) interference to regulate protein expression has become an important research topic and gene therapy tool, and therefore, finding suitable vehicles for delivery of small RNAs into cells is of crucial importance. Layered double metal hydroxides such as hydrotalcite (HT) have shown great promise as nonviral vectors for transport of deoxyribose nucleic acid (DNA), proteins, and drugs into cells, but the adsorption of RNAs to these materials has been little explored. In this study, the binding of small RNAs with different lengths and levels of secondary structure to HT nanoparticles has been analyzed and compared to …