Amino Acids, Peptides, and Proteins Commons^™

Comparative Analysis Of Conformational Dynamics And Systematic Characterization Of Cryptic Pockets In The Sars-Cov-2 Omicron Ba.2, Ba.2.75 And Xbb.1 Spike Complexes With The Ace2 Host Receptor: Confluence Of Binding And Structural Plasticity In Mediating Networks Of Conserved Allosteric Sites, Mohammed Alshahrani, Grace Gupta, Sian Xiao, Peng Tao, Gennady M. Verkhivker

Mathematics, Physics, and Computer Science Faculty Articles and Research

In the current study, we explore coarse-grained simulations and atomistic molecular dynamics together with binding energetics scanning and cryptic pocket detection in a comparative examination of conformational landscapes and systematic characterization of allosteric binding sites in the SARS-CoV-2 Omicron BA.2, BA.2.75 and XBB.1 spike full-length trimer complexes with the host receptor ACE2. Microsecond simulations, Markov state models and mutational scanning of binding energies of the SARS-CoV-2 BA.2 and BA.2.75 receptor binding domain complexes revealed the increased thermodynamic stabilization of the BA.2.75 variant and significant dynamic differences between these Omicron variants. Molecular simulations of the SARS-CoV-2 Omicron spike full-length trimer complexes …

Purification And Biochemical Characterization Of The Dna Binding Domain Of The Nitrogenase Transcriptional Activator Nifa From Gluconacetobacter Diazotrophicus, Heidi G. Standke, Lois Kim, Cedric P. Owens

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

NifA is a σ⁵⁴ activator that turns on bacterial nitrogen fixation under reducing conditions and when fixed cellular nitrogen levels are low. The redox sensing mechanism in NifA is poorly understood. In α- and β-proteobacteria, redox sensing involves two pairs of Cys residues within and immediately following the protein’s central AAA⁺ domain. In this work, we examine if an additional Cys pair that is part of a C(X)5 C motif and located immediately upstream of the DNA binding domain of NifA from the α-proteobacterium Gluconacetobacter diazotrophicus (Gd) is involved in redox sensing. We hypothesize that the …

Characterization Of Epithelial Growth Factor Transcripts Identified In Crotalus Atrox Venom, Ivan Lopez, Ying Jia

Research Symposium

Epithelial Growth Factor (EGF) is the primary source in regeneration and stimulation of essential fibroblasts cells commonly found in epithelium. Studies have shown that snake venom components are becoming a growing factor in treating illnesses such as cancer, muscular dystrophy, chronic pain, blood pressure, blood clotting, etc. EGF in human cells contains a promising quaternary structure that can bind to snake venom metalloproteinases, proposing a means of activating biochemical responses through protein-protein interactions to regulate unwanted cellular functions. This supports promising research in achieving a greater understanding of regulation along cellular pathways through ligands, increasing the likelihood of targeting unwanted …

Differential Cortical Monoamines Release During Exercise In Rats Chronically Implanted With Microdialysis Probes, Christine G. Gerin

Research Symposium

Physical exercise is known to positively influence mood, to reduce anxiety and to improve reaction to stress. Cerebral monoaminergic systems are thought to underly the neurochemical influence of exercise on mood and behavior. We hypothesized that beneficial effects of exercise can be shown by variations of neurotransmitters release in the cerebral cortex. We aimed at demonstrating that there is a temporal relationship between release of plasma and cerebral monoamines (A, NA, 5-HT, DA) and spontaneous running exercise in rats. Ten Spague Dawley rats (250 g) were chronically implanted (for up to 39 days) with a left common carotid cannula and …

Exploring Conformational Landscapes And Cryptic Binding Pockets In Distinct Functional States Of The Sars-Cov-2 Omicron Ba.1 And Ba.2 Trimers: Mutation-Induced Modulation Of Protein Dynamics And Network-Guided Prediction Of Variant-Specific Allosteric Binding Sites, Gennady M. Verkhivker, Mohammed Alshahrani, Grace Gupta

Mathematics, Physics, and Computer Science Faculty Articles and Research

A significant body of experimental structures of SARS-CoV-2 spike trimers for the BA.1 and BA.2 variants revealed a considerable plasticity of the spike protein and the emergence of druggable binding pockets. Understanding the interplay of conformational dynamics changes induced by the Omicron variants and the identification of cryptic dynamic binding pockets in the S protein is of paramount importance as exploring broad-spectrum antiviral agents to combat the emerging variants is imperative. In the current study, we explore conformational landscapes and characterize the universe of binding pockets in multiple open and closed functional spike states of the BA.1 and BA.2 Omicron …

Nanodiscs: A Novel Approach To The Study Of The Methionine Abc Transporter System, Michael T. Winslow

Master's Theses

Membrane transporter proteins play the vital role of moving compounds in and out of the cell and are essential for all living organisms. ATP Binding Cassette (ABC) family transporters function both as importers and exporters in prokaryotes. MetNI is an E. coli Type I ABC transporter responsible for the uptake of methionine into the cytosol from the cell periplasmic space through the cell membrane to maintain intracellular methionine pools. ABC transporters, like other membrane proteins, are most often mechanistically and structurally studied in vitro, solubilized by detergents. However, detergent micelles may affect the conformational changes of membrane proteins relative to …

Additive Effects Of Cyclic Peptide [R4w4] When Added Alongside Azithromycin And Rifampicin Against Mycobacterium Avium Infection, Melissa Kelley, Kayvan Sasaninia, Arbi Abnousian, Ali Badaoui, James Owens, Abrianna Beever, Nala Kachour, Rakesh Kumar Tiwari, Vishwanath Venketaraman

Pharmacy Faculty Articles and Research

Mycobacterium avium (M. avium), a type of nontuberculous mycobacteria (NTM), poses a risk for pulmonary infections and disseminated infections in immunocompromised individuals. Conventional treatment consists of a 12-month regimen of the first-line antibiotics rifampicin and azithromycin. However, the treatment duration and low antibiotic tolerability present challenges in the treatment of M. avium infection. Furthermore, the emergence of multidrug-resistant mycobacterium strains prompts a need for novel treatments against M. avium infection. This study aims to test the efficacy of a novel antimicrobial peptide, cyclic [R4W4], alongside the first-line antibiotics azithromycin and rifampicin in reducing M. avium survival. Colony-forming unit (CFU) …

Α7 Nicotinic Acetylcholine Receptor Interaction With G Proteins In Breast Cancer Cell Proliferation, Motility, And Calcium Signaling, Murat Oz, Justin R. King, Keun-Hang Susan Yang, Sarah Khushaish, Yulia Tchugunova, Maitham A. Khajah, Yunus A. Luqmani, Nadine Kabbani

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Chronic smoking is a primary risk factor for breast cancer due to the presence of various toxins and carcinogens within tobacco products. Nicotine is the primary addictive component of tobacco products and has been shown to promote breast cancer cell proliferation and metastases. Nicotine activates nicotinic acetylcholine receptors (nAChRs) that are expressed in cancer cell lines. Here, we examine the role of the α7 nAChR in coupling to heterotrimeric G proteins within breast cancer MCF-7 cells. Pharmacological activation of the α7 nAChR using choline or nicotine was found to increase proliferation, motility, and calcium signaling in MCF-7 cells. This effect …

Targeting Mcl-1 By A Small Molecule Nsc260594 For Triple-Negative Breast Cancer Therapy, Shengli Dong, Margarite D. Matossian, Hassan Yousefi, Maninder Khosla, Bridgette M. Collins-Burow, Matthew E. Burow, Suresh K. Alahari

School of Graduate Studies Faculty Publications

Triple-negative breast cancers (TNBCs) are aggressive forms of breast cancer and tend to grow and spread more quickly than most other types of breast cancer. TNBCs can neither be targeted by hormonal therapies nor the antibody trastuzumab that targets the HER2 protein. There are urgent unmet medical needs to develop targeted drugs for TNBCs. We identified a small molecule NSC260594 from the NCI diversity set IV compound library. NSC260594 exhibited dramatic cytotoxicity in multiple TNBCs in a dose-and time-dependent manner. NSC260594 inhibited the Myeloid cell leukemia-1 (Mcl-1) expression through downregulation of Wnt signaling proteins. Consistent with this, NSC260594 treatment increased …

The Structural Characterization And Bioactivity Assessment Of Nonspecific Lipid Transfer Protein 1 (Nsltp1) From Caraway (Carum Carvi) Seeds, Taibah Aldakhil, Saud O. Alshammari, Bushra Siraj, Bishoy El-Aarag, Shamshad Zarina, David Salehi, Aftab Ahmed

Pharmacy Faculty Articles and Research

Background

Carum carvi (caraway) of the Apiaceae family has been used in many cultures as a cooking spice and part of the folk medicine. Previous reports primarily focus on the medicinal properties of caraway seed essential oil and the whole seeds extract. However, no effort has been made to study caraway proteins and their potential pharmacological properties, including nonspecific lipid transfer protein (nsLTP), necessitating further research. The current study aimed to characterize nonspecific lipid transfer protein 1 (nsLTP1) from caraway seed, determine its three-dimensional structure, and analyze protein–ligand complex interactions through docking studies. We also evaluated nsLTP1 in vitro cytotoxic …

High Glucose-Upregulated Pd-L1 Expression Through Ras Signaling-Driven Downregulation Of Ptrh1 Leads To Suppression Of T Cell Cytotoxic Function In Tumor Environment, Chenggang Gao, Jiaoshun Chen, Jianwei Bai, Haoxiang Zhang, Yanyi Tao, Shihong Wu, Hehe Li, Heshui Wu, Qiang Shen, Tao Yin

School of Graduate Studies Faculty Publications

Background: Nearly 80% of patients with pancreatic cancer suffer from glucose intolerance or diabetes. Pancreatic cancer complicated by diabetes has a more immunosuppressive tumor microenvironment (TME) and is associated with a worse prognosis. The relationship between glucose metabolism and programmed cell death-Ligand 1 (PD-L1) is close and complex. It is important to explore the regulation of high glucose on PD-L1 expression in pancreatic cancer and its effect on infiltrating immune effectors in the tumor microenvironment. Methods: Diabetic murine models (C57BL/6) were used to reveal different immune landscape in euglycemic and hyperglycemic pancreatic tumor microenvironment. Bioinformatics, WB, iRIP [Improved RNA Binding …

Cancer Cell-Specific Cgas/Sting Signaling Pathway In The Era Of Advancing Cancer Cell Biology, Vijay Kumar, Caitlin Bauer, John H. Stewart

School of Graduate Studies Faculty Publications

Pattern-recognition receptors (PRRs) are critical to recognizing endogenous and exogenous threats to mount a protective proinflammatory innate immune response. PRRs may be located on the outer cell membrane, cytosol, and nucleus. The cGAS/STING signaling pathway is a cytosolic PRR system. Notably, cGAS is also present in the nucleus. The cGAS-mediated recognition of cytosolic dsDNA and its cleavage into cGAMP activates STING. Furthermore, STING activation through its downstream signaling triggers different interferon-stimulating genes (ISGs), initiating the release of type 1 interferons (IFNs) and NF-κB-mediated release of proinflammatory cytokines and molecules. Activating cGAS/STING generates type 1 IFN, which may prevent cellular transformation …

Yes-Associated Protein-1 Overexpression In Ocular Surface Squamous Neoplasia; A Potential Diagnostic Marker And Therapeutic Target, Peter Julius, Stepfanie N. Siyumbwa, Fred Maate, Phyllis Moonga, Guobin Kang, Trevor Kaile, John T. West, Charles Wood, Peter C. Angeletti

School of Graduate Studies Faculty Publications

Yes-associated protein-1 (YAP-1) is a Hippo system transcription factor, which serves as an oncogene in squamous cell carcinoma, and several solid tumors when the Hippo pathway is dysregulated. Yet, the activity of YAP-1 in ocular surface squamous neoplasia (OSSN) has not been determined. Here, we investigate the relationship between YAP-1 overexpression and OSSN. Using a cross-sectional study design, we recruited 227 OSSN patients from the University Teaching Hospitals in Lusaka, Zambia. Immunohistochemistry was used to assess YAP-1 protein overexpression in tumor tissue relative to surrounding benign squamous epithelium. OSSN patient samples (preinvasive, n = 62, 27% and invasive, n = …

Enhancement Of Tki Sensitivity In Lung Adenocarcinoma Through M6a-Dependent Translational Repression Of Wnt Signaling By Circ-Fbxw7, Kai Li, Zi Yang Peng, Rui Wang, Xiang Li, Ning Du, Da Peng Liu, Jia Zhang, Yun Feng Zhang, Lei Ma, Ye Sun, Shou Ching Tang, Hong Ren, Yi Ping Yang, Xin Sun

School of Medicine Faculty Publications

Background: Tyrosine kinase inhibitors (TKIs) that specifically target mutational points in the EGFR gene have significantly reduced suffering and provided greater relief to patients with lung adenocarcinoma (LUAD). The third-generation EGFR-TKI, Osimertinib, has been successfully employed in clinical treatments to overcome resistance to both original and acquired T790M and L858R mutational points. Nevertheless, the issue of treatment failure response has emerged as an insurmountable problem. Methods: By employing a combination of multiple and integrated approaches, we successfully identified a distinct population within the tumor group that plays a significant role in carcinogenesis, resistance, and recurrence. Our research suggests that addressing …

Targeting Cgas/Sting Signaling-Mediated Myeloid Immune Cell Dysfunction In Time, Vijay Kumar, Caitlin Bauer, John H. Stewart

School of Graduate Studies Faculty Publications

Myeloid immune cells (MICs) are potent innate immune cells serving as first responders to invading pathogens and internal changes to cellular homeostasis. Cancer is a stage of altered cellular homeostasis that can originate in response to different pathogens, chemical carcinogens, and internal genetic/epigenetic changes. MICs express several pattern recognition receptors (PRRs) on their membranes, cytosol, and organelles, recognizing systemic, tissue, and organ-specific altered homeostasis. cGAS/STING signaling is a cytosolic PRR system for identifying cytosolic double-stranded DNA (dsDNA) in a sequence-independent but size-dependent manner. The longer the cytosolic dsDNA size, the stronger the cGAS/STING signaling activation with increased type 1 interferon …

The Pros Of Changing Trna Identity, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The notion that errors in protein synthesis are universally harmful to the cell has been questioned by findings that suggest such mistakes may sometimes be beneficial. However, how often these beneficial mistakes arise from programmed changes in gene expression as opposed to reduced accuracy of the translation machinery is still unclear. A new study published in JBC shows that some bacteria have beneficially evolved the ability to mistranslate specific parts of the genetic code, a trait that allows improved antibiotic resistance.

Systemic Review Of Clot Retraction Modulators, Alaina Guilbeau, Rinku Majumder

School of Graduate Studies Faculty Publications

Through a process termed clot retraction, platelets cause thrombi to shrink and become more stable. After platelets are activated via inside-out signaling, glycoprotein αIIbβIII binds to fibrinogen and initiates a cascade of intracellular signaling that ends in actin remodeling, which causes the platelet to change its shape. Clot retraction is also important for wound healing. Although the detailed molecular biology of clot retraction is only partially understood, various substances and physiological conditions modulate clot retraction. In this review, we describe some of the current literature pertaining to clot retraction modulators. In addition, we discuss compounds from Cudrania trucuspidata, Arctium lappa, …

KCa2 And KCa3.1 Channels In The Airways: A New Therapeutic Target, Razan Orfali, Ali Alfaiz, Mohammad Asikur Rahman, Liz Lau, Young-Woo Nam, Miao Zhang

Pharmacy Faculty Articles and Research

K⁺ channels are involved in many critical functions in lung physiology. Recently, the family of Ca²⁺-activated K⁺ channels (K_Ca) has received more attention, and a massive amount of effort has been devoted to developing selective medications targeting these channels. Within the family of K_Ca channels, three small-conductance Ca²⁺-activated K⁺ (K_Ca2) channel subtypes, together with the intermediate-conductance K_Ca3.1 channel, are voltage-independent K⁺ channels, and they mediate Ca²⁺-induced membrane hyperpolarization. Many K_Ca2 channel members are involved in crucial roles in physiological and pathological …

Cyclic Peptides With Antifungal Properties Derived From Bacteria, Fungi, Plants, And Synthetic Sources, Naiera M. Helmy, Keykavous Parang

Pharmacy Faculty Articles and Research

Fungal infections remain a significant concern for human health. The emergence of microbial resistance, the improper use of antimicrobial drugs, and the need for fewer toxic antifungal treatments in immunocompromised patients have sparked substantial interest in antifungal research. Cyclic peptides, classified as antifungal peptides, have been in development as potential antifungal agents since 1948. In recent years, there has been growing attention from the scientific community to explore cyclic peptides as a promising strategy for combating antifungal infections caused by pathogenic fungi. The identification of antifungal cyclic peptides from various sources has been possible due to the widespread interest in …

7-Ketocholesterol Promotes Retinal Pigment Epithelium Senescence And Fibrosis Of Choroidal Neovascularization Via Iqgap1 Phosphorylation-Dependent Signaling, Haibo Wang, Aniket Ramshekar, Thaonhi Cung, Chris Wallace-Carrete, Chandler Zaugg, Jasmine Nguyen, Gregory J. Stoddard, M. Elizabeth Hartnett

School of Medicine Faculty Publications

Accumulation of 7-ketocholesterol (7KC) occurs in age-related macular degeneration (AMD) and was found previously to promote fibrosis, an untreatable cause of vision loss, partly through induction of endothelial-mesenchymal transition. To address the hypothesis that 7KC causes mesenchymal transition of retinal pigment epithelial cells (RPE), we exposed human primary RPE (hRPE) to 7KC or a control. 7KC-treated hRPE did not manifest increased mesenchymal markers, but instead maintained RPE-specific proteins and exhibited signs of senescence with increased serine phosphorylation of histone H3, serine/threonine phosphorylation of mammalian target of rapamycin (p-mTOR), p16 and p21, β-galactosidase labeling, and reduced LaminB1, suggesting senescence. The cells …