Amino Acids, Peptides, and Proteins Commons^™

Leptin Regulates Cd16 Expression On Human Monocytes In A Sex-Specific Manner, Joseph G. Cannon, Gyanendra Sharma, Gloria Sloan, Christiana Dimitropoulou, R. Randall Baker, Andrew Mazzoli, Barbara Kraj, Anthony Mulloy, Miriam Cortez-Cooper

School of Medical Diagnostics & Translational Sciences Publications

Fat mass is linked mechanistically to the cardiovascular system through leptin, a 16 kDa protein produced primarily by adipocytes. In addition to increasing blood pressure via hypothalamic-sympathetic pathways, leptin stimulates monocyte migration, cytokine secretion, and other functions that contribute to atherosclerotic plaque development. These functions are also characteristics of CD16-positive monocytes that have been implicated in the clinical progression of atherosclerosis. This investigation sought to determine if leptin promoted the development of such CD16-positive monocytes. Cells from 45 healthy men and women with age ranging from 20 to 59 years were analyzed. Circulating numbers of CD14++16++ monocytes, which are primary …

Non-Raft Ac2 Defines A Camp Signaling Compartment That Selectively Regulates Il-6 Expression In Airway Smooth Muscle Cells, Amy S. Bogard, Anna V. Birg, Rennolds S. Ostrom

Pharmacy Faculty Articles and Research

Adenylyl cyclase (AC) isoforms differ in their tissue distribution, cellular localization, regulation, and protein interactions. Most cell types express multiple AC isoforms. We hypothesized that cAMP produced by different AC isoforms regulates unique cellular responses in human bronchial smooth muscle cells (BSMC). Overexpression of AC2, AC3, or AC6 had distinct effects on forskolin (Fsk)-induced expression of a number of known cAMP-responsive genes. These data show that different AC isoforms can differentially regulate gene expression. Most notable, overexpression and activation of AC2 enhanced interleukin 6 (IL-6) expression, but overexpression of AC3 or AC6 had no effect. IL-6 production by BSMC was …

Cyclic Peptide-Capped Gold Nanoparticles For Enhanced Sirna Delivery, Amir Nasrolahi Shirazi, Karissa L. Paquin, Niall G. Howlett, Dindyal Mandal, Keykavous Parang

Pharmacy Faculty Articles and Research

Previously, we have reported the synthesis of a homochiral L-cyclic peptide [WR]5 and its use for delivery of anti-HIV drugs and biomolecules. A physical mixture of HAuCl4 and the peptide generated peptide-capped gold nanoparticles. Here, [WR]5 and [WR]5-AuNPs were tested for their efficiency to deliver a small interfering RNA molecule (siRNA) in human cervix adenocarcinoma (HeLa) cells. Flow cytometry investigation revealed that the intracellular uptake of a fluorescence-labeled non-targeting siRNA (200 nM) was enhanced in the presence of [WR]5 and [WR]5-AuNPs by 2- and 3.8-fold when compared with that of siRNA alone after 24 h incubation. Comparative toxicity results showed …

Involvement Of Sigma-1 Receptors In The Antidepressant-Like Effects Of Dextromethorphan, Linda Nguyen, Matthew J. Robson, Jason R. Healy, Anna L. Scandinaro, Rae Reiko Matsumoto

Faculty Publications & Research of the TUC College of Pharmacy

Dextromethorphan is an antitussive with a high margin of safety that has been hypothesized to display rapid-acting antidepressant activity based on pharmacodynamic similarities to the N-methyl-D-aspartate (NMDA) receptor antagonist ketamine. In addition to binding to NMDA receptors, dextromethorphan binds to sigma-1 (s1) receptors, which are believed to be protein targets for a potential new class of antidepressant medications. The purpose of this study was to determine whether dextromethorphan elicits antidepressant-like effects and the involvement of s1 receptors in mediating its antidepressant-like actions. The antidepressant-like effects of dextromethorphan were assessed in male, Swiss Webster mice using the forced swim test. Next, …

Cardiac Troponin Assessment Following Atrial Fibrillation Ablation: Implications For Chest Pain Evaluation, Jason C. Rubenstein, Jason T. Jacobson, Jeffrey J. Goldberger, Rod Passman, Alan H. Kadish, Michael H. Kim

Office of the President Publications and Research

Background: The range of elevation of troponin I (tI) that is within expected limits from left atrial radiofrequency ablation for atrial fibrillation (AF) is not well described, though such information may be of clinical value.

Objectives: Identify the expected range of tI values post-atrial fibrillation (AF) ablation.

Methods: 31 patients undergoing AF ablation had a single tI level drawn the day following the procedure. Clinical variables were also collected, such as ablation type and radiofrequency (RF) time.

Results: Paroxysmal AF was present in 23 patients, and 8 had chronic AF. The average RF time was 2627.8 …

Carbocyclodipeptides As Modified Nucleosides: Synthesis And Anti- Hiv Activities, Bhupender S. Chhikara, M. Sudershan Rao, V. Kameshwara Rao, Anil Kumar, Karen W. Buckheit, Robert W. Buckheit Jr., Keykavous Parang

Pharmacy Faculty Articles and Research

A new class of nucleoside analogues were synthesized using cyclic dipeptides and modified 2′-deoxyfuranoribose sugars to introduce flexibility by peptides in place of common nucleoside bases and to determine their biological properties. The synthesis was carried out by coupling of a protected ribose sugar with synthesized dipeptides in the presence of hexamethyldisilazane and trimethylsilyltriflate. The final products were characterized by NMR and high-resolution MS-TOF spectroscopy. The compounds were evaluated for anti-HIV activities. 1-(4-Azido-5-(hydroxymethyl)tetrahydrofuran-2-yl)-3,6-diisopropylpiperazine-2,5-dione (compound 14) containing 3- and 6-isopropyl groups in the base and 3′-azide (EC50 = 1.96 μmol/L) was the most potent compound among all of the synthesized analogs.

Alteration Of Host Cell Ubiquitination By The Intracellular Bacterial Pathogen Coxiella Burnetii, Lindsay Pritchett, Daniel E. Voth

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

The intracellular bacterial agent of Q fever, Coxiella burnetii, replicates within a phagolysosomelike parasitophorous vacuole (PV) in human macrophages and delivers effector proteins to the host cytosol via a Dot/Icm type IV secretion system (T4SS). The T4SS effectors are critical for PV formation and prevention of host cell death that allows sufficient time for bacterial replication. Recruitment of ubiquitin-related components to the C. burnetii PV is also predicted to be involved in PV formation and bacterial replication and is likely controlled by effector proteins. In this study, we assessed the role of the Dot/Icm T4SS in regulating ubiquitination by comparing …

Computational Modeling Of Allosteric Regulation In The Hsp90 Chaperones: A Statistical Ensemble Analysis Of Protein Structure Networks And Allosteric Communications, Kristin Blacklock, Gennady M. Verkhivker

Mathematics, Physics, and Computer Science Faculty Articles and Research

A fundamental role of the Hsp90 chaperone in regulating functional activity of diverse protein clients is essential for the integrity of signaling networks. In this work we have combined biophysical simulations of the Hsp90 crystal structures with the protein structure network analysis to characterize the statistical ensemble of allosteric interaction networks and communication pathways in the Hsp90 chaperones. We have found that principal structurally stable communities could be preserved during dynamic changes in the conformational ensemble. The dominant contribution of the inter-domain rigidity to the interaction networks has emerged as a common factor responsible for the thermodynamic stability of the …

Allosteric Regulation Of The Hsp90 Dynamics And Stability By Client Recruiter Cochaperones: Protein Structure Network Modeling, Kristin Blacklock, Gennady M. Verkhivker

Mathematics, Physics, and Computer Science Faculty Articles and Research

The fundamental role of the Hsp90 chaperone in supporting functional activity of diverse protein clients is anchored by specific cochaperones. A family of immune sensing client proteins is delivered to the Hsp90 system with the aid of cochaperones Sgt1 and Rar1 that act cooperatively with Hsp90 to form allosterically regulated dynamic complexes. In this work, functional dynamics and protein structure network modeling are combined to dissect molecular mechanisms of Hsp90 regulation by the client recruiter cochaperones. Dynamic signatures of the Hsp90-cochaperone complexes are manifested in differential modulation of the conformational mobility in the Hsp90 lid motif. Consistent with the experiments, …

Amphiphilic Triazolyl Peptides: Synthesis And Evaluation As Nanostructures, Naser Sayeh, Amir Nasrolahi Shirazi, Donghoon Oh, Jiadong Sun, David Rowley, Antara Banerjee, Arpita Yadav, Rakesh Tiwari, Keykavous Parang

Pharmacy Faculty Articles and Research

A new class of amphiphilic triazolyl peptides was designed and synthesized from peptide-based building blocks containing alkyne and azide functional groups namely linear (W(pG))3, cyclic[W(pG)]3, and Ac-K(N3)R-NH2,where W, R, K, and pG represent tryptophan, arginine, lysine, and propargylglycine residues, respectively. The linear (W(pG))3 and cyclic [W(pG)]3 peptides containing alkyne residues were conjugated with Ac-K(N3)R-NH2 functionalized with azide group through click chemistry in the presence of CuSO4.5H2O, Cu (powder), sodium ascorbate, and N,N-disopropylethylamine in methanol:water to afford amphiphilic triazolyl linear-linear (WG(triazole-KR-NH2))3 and cyclic-linear [WG(triazole-KR-NH2)]3 peptides, respectively. The secondary structures of both peptides were similar to a distorted α-helix as shown by …

Beta-Alanine Suppresses Malignant Breast Epithelial Cell Aggressiveness Through Alterations In Metabolism And Cellular Acidity In Vitro, Roger A. Vaughan, Nicholas P. Gannon, Randi Garcia-Smith, Yamhilette Licon-Munoz, Miguel A. Barberena, Marco Bisoffi, Kristina A. Trujillo

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Background: Deregulated energetics is a property of most cancer cells. This phenomenon, known as the Warburg Effect or aerobic glycolysis, is characterized by increased glucose uptake, lactate export and extracellular acidification, even in the presence of oxygen. beta-alanine is a non-essential amino acid that has previously been shown to be metabolized into carnosine, which functions as an intracellular buffer. Because of this buffering capacity, we investigated the effects of beta-alanine on the metabolic cancerous phenotype.

Methods: Non-malignant MCF-10a and malignant MCF-7 breast epithelial cells were treated with beta-alanine at 100 mM for 24 hours. Aerobic glycolysis was quantified …

Effect Of Chronic Angiotensin Ii Infusion On Plasma Tnfalpha And Il 6 Levels In Adiponectin Deficient Mice, Alexis O'Brien, Minnette Smith, Jaya Pamidimukkala

College of Osteopathic Medicine (TUN) Publications and Research

Chronic low grade inflammation plays an integral part in the development of many types of cardiovascular diseases. Adipose tissue is a well known source of many proinflammatory mediators. Adiponectin (APN) is one of the few proteins secreted by the adipose tissue that is known to have anti-inflammatory properties. Our research goal is to understand if APN deficiency contributes to a proinflammatory milieu especially when provided with an appropriate stimulus. Angiotensin II (ANGII) is a well known prohypertensive agent. Recently, ANGII has emerged as a growth factor and stimulator of proinflammatory cytokine expression in cardiovascular & renal tissue. The present study …

A Potential Mechanism For Extracellular Matrix Induction Of Breast Cancer Cell Normality, Robert D. Bruno, Gilbert H. Smith

School of Medical Diagnostics & Translational Sciences Publications

Extracellular matrix proteins from embryonic mesenchyme have a normalizing effect on cancer cells in vitro and slow tumor growth in vivo. This concept is suggestive of a new method for controlling the growth and spread of existing cancer cells in situ and indicates the possibility that extracellular proteins and/or embryonic mesenchymal fibroblasts may represent a fertile subject for study of new anti-cancer treatments.

Hydropathic Interactions And Protein Structure: Utilizing The Hint Force Field In Structure Prediction And Protein‐Protein Docking., Mostafa H. Ahmed

Theses and Dissertations

Protein structure predication is a field of computational molecular modeling with an enormous potential for improvement. Side-chain geometry prediction is a critical component of this process that is crucial for computational protein structure predication as well as crystallographers in refining experimentally determined protein crystal structures. The cornerstone of side-chain geometry prediction are side-chain rotamer libraries, usually obtained through exhaustive statistical analysis of existing protein structures. Little is known, however, about the driving forces leading to the preference or suitability of one rotamer over another. Construction of 3D hydropathic interaction maps for nearly 30,000 tyrosines extracted from the PDB reveals their …

Molecular Evolution Of Protein-Rna Mimicry As A Mechanism For Translational Control, Assaf Katz, Lindsey Solden, S. Betty Zou, William Wiley Navarre, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Elongation factor P (EF-P) is a conserved ribosome-binding protein that structurally mimics tRNA to enable the synthesis of peptides containing motifs that otherwise would induce translational stalling, including polyproline. In many bacteria, EF-P function requires post-translational modification with (R)-β-lysine by the lysyl-tRNA synthetase paralog PoxA. To investigate how recognition of EF-P by PoxA evolved from tRNA recognition by aminoacyl-tRNA synthetases, we compared the roles of EF-P/PoxA polar contacts with analogous interactions in a closely related tRNA/synthetase complex. PoxA was found to recognize EF-P solely via identity elements in the acceptor loop, the domain of the protein that interacts with the …

Biochemical Assay Optimization And Computational Screening Efforts To Identify Potential Luxs Inhibitors, Keeshia Q. Wang

Master's Theses

Quorum sensing (QS) is a process of coordination of bacterial gene expression in response to cell population. System two QS is regulated by the small signaling molecule autoinducer-2 (AI-2) and is implicated in the infectious behaviors of various bacterial species. AI-2 is biosynthesized from S-ribosylhomocysteine (SRH) by the enzyme LuxS and induces interspecies cell-to-cell communication. Inhibition of LuxS would therefore inhibit interspecies QS. Herein, a search for novel molecular species that will competitively bind with SRH in the LuxS binding site is performed in silico. Computational screening results are then validated in vitro using an optimized LuxS inhibition …

Differential Actions Of Orexin Receptors In Brainstem Cholinergic And Monoaminergic Neurons Revealed By Receptor Knockouts: Implications For Orexinergic Signaling In Arousal And Narcolepsy, Kristi Kohlmeier, Christopher Tyler, Mike Kalogiannis, Masaru Ishibashi, Iryna Gumenchuk, Masashi Yanagisawa, Christopher S. Leonard

NYMC Faculty Publications

Orexin neuropeptides influence multiple homeostatic functions and play an essential role in the expression of normal sleep-wake behavior. While their two known receptors (OX1 and OX2) are targets for novel pharmacotherapeutics, the actions mediated by each receptor remain largely unexplored. Using brain slices from mice constitutively lacking either receptor, we used whole-cell and Ca(2+) imaging methods to delineate the cellular actions of each receptor within cholinergic [laterodorsal tegmental nucleus (LDT)] and monoaminergic [dorsal raphe (DR) and locus coeruleus (LC)] brainstem nuclei-where orexins promote arousal and suppress REM sleep. In slices from OX(-/-) 2 mice, orexin-A (300 nM) elicited wild-type responses …

Investigation Of Commercial Milk Enzyme-Linked Immunosorbent Assay (Elisa) Kits: Specificity And Utility For Residues Of Foods Subjected To Proteolysis During Processing, Katherine O. Ivens

Department of Food Science and Technology: Dissertations, Theses, and Student Research

Analytical methods, such as enzyme-linked immunosorbent assays (ELISA), are used to detect and quantify residues from allergenic sources in food products. However, ELISAs have not been validated for use in foods that have been exposed to proteolysis. This thesis explores the specificities, sensitivities, and capabilities of commercially-available milk ELISA kits for detecting milk residues in cheeses that have undergone varying degrees of proteolysis.

The specificity, accuracy, and consistency of twelve commercially-available milk ELISA kits for individual milk proteins and commonly used milk-derived ingredients, including α-,β-, and κ-casein, β-lactoglobulin, α-lactalbumin, non-fat dry milk, sodium caseinate, and whey protein concentrate were evaluated. …

Killerflip: A Novel Lytic Peptide Specifically Inducing Cancer Cell Death, B Pennarun, G. Gaidos, O Bucur, A Tinari

Dartmouth Scholarship

One of the objectives in the development of effective cancer therapy is induction of tumor-selective cell death. Toward this end, we have identified a small peptide that, when introduced into cells via a TAT cell-delivery system, shows a remarkably potent cytoxicity in a variety of cancer cell lines and inhibits tumor growth in vivo, whereas sparing normal cells and tissues. This fusion peptide was named killer FLIP as its sequence was derived from the C-terminal domain of c-FLIP, an anti-apoptotic protein. Using structure activity analysis, we determined the minimal bioactive core of killerFLIP, namely killerFLIP-E. Structural analysis of cells using …

A Computational Model Reveals The Action Of Gβγ At An Inter-Subunit Cleft To Activate Girk1 Channels, Rahul Mahajan, Junghoon Ha, Miao Zhang, Takeharu Kawano, Tohru Kozasa, Diomedes E. Logothetis

Pharmacy Faculty Articles and Research

The atrial G protein-regulated inwardly rectifying K+ (GIRK1 and GIRK4) heterotetrameric channels underlie the acetylcholine-induced K+ current responsible for vagal inhibition of heart rate and are activated by the G protein βγ subunits (Gβγ). We used a multistage protein-protein docking approach with data from published structures of GIRK1 and Gβγ to generate an experimentally testable interaction model of Gβγ docked onto the cytosolic domains of the GIRK1 homotetramer. The model suggested a mechanism by which Gβγ promotes the open state of a specific cytosolic gate in the channel, the G-loop gate. The predicted structure showed that the Gβ subunit interacts …