Chemistry Commons^™

Reactivity Of Aminophenols In Forming Nitrogen-Containing Brown Carbon From Iron-Catalyzed Reactions, Hind A. Al-Abadleh, Fatemeh Motaghedi, Wisam Mohammed, Md Sohel Rana, Kotiba A. Malek, Dewansh Rastogi, Akua A. Asa-Awuku, Marcelo I. Guzman

Chemistry Faculty Publications

Nitrogen-containing organic carbon (NOC) in atmospheric particles is an important class of brown carbon (BrC). Redox active NOC like aminophenols received little attention in their ability to form BrC. Here we show that iron can catalyze dark oxidative oligomerization of o- and p-aminophenols under simulated aerosol and cloud conditions (pH 1–7, and ionic strength 0.01–1 M). Homogeneous aqueous phase reactions were conducted using soluble Fe(III), where particle growth/agglomeration were monitored using dynamic light scattering. Mass yield experiments of insoluble soot-like dark brown to black particles were as high as 40%. Hygroscopicity growth factors (κ) of these …

Direct Ink 3d Printing Of Porous Carbon Monoliths For Gas Separations, Marisa L. Comroe, Kurt W. Kolasinski, Dipendu Saha

Chemistry Faculty Publications

Additive manufacturing or 3D printing is the advanced method of manufacturing monolithic adsorbent materials. Unlike beads or pellets, 3D monolithic adsorbents possess the advantages of widespread structural varieties, low heat and mass transfer resistance, and low channeling of fluids. Despite a large volume of research on 3D printing of adsorbents having been reported, such studies on porous carbons are highly limited. In this work, we have reported direct ink 3D printing of porous carbon; the ink consisted of commercial activated carbon, a gel of poly(4-vinylphenol) and Pluronic F127 as plasticizer, and bentonite as the binder. The 3D printing was performed …

Multimodal Cotranslational Interactions Direct Assembly Of The Human Multi-Trna Synthetase Complex, Krishnendu Khan, Briana Long, Valentin Gogonea, Gauravi M. Deshpande, Kommireddy Vasu, Paul L. Fox

Chemistry Faculty Publications

Amino acid ligation to cognate transfer RNAs (tRNAs) is catalyzed by aminoacyl-tRNA synthetases (aaRSs)-essential interpreters of the genetic code during translation. Mammalian cells harbor 20 cytoplasmic aaRSs, out of which 9 (in 8 proteins), with 3 non-aaRS proteins, AIMPs 1 to 3, form the similar to 1.25-MDa multi-tRNA synthetase complex (MSC). The function of MSC remains uncertain, as does its mechanism of assembly. Constituents of multiprotein complexes encounter obstacles during assembly, including inappropriate interactions, topological constraints, premature degradation of unassembled subunits, and suboptimal stoichiometry. To facilitate orderly and efficient complex formation, some complexes are assembled cotranslationally by a mechanism in …

The Role Of Crystal Packing On The Optical Response Of Trialkyltetrelethynyl Acenes, Ling-Yi Huang, Qianxiang Ai, Chad Risko

Chemistry Faculty Publications

The electronic and optical responses of an organic semiconductor (OSC) are dictated by the chemistries of the molecular or polymer building blocks and how these chromophores pack in the solid state. Understanding the physicochemical nature of these responses is not only critical for determining the OSC performance for a particular application, but the UV/visible optical response may also be of potential use to determine aspects of the molecular-scale solid-state packing for crystal polymorphs or thin-film morphologies that are difficult to determine otherwise. To probe these relationships, we report the quantum-chemical investigation of a series of trialkyltetrelethynyl acenes (tetrel = silicon …

Characteristics And Health Effects Of Particulate Matter Emitted From A Waste Sorting Plant, Abdullah Barkhordari, Marcelo I. Guzman, Gholamreza Ebrahimzadeh, Armin Sorooshian, Mahdieh Delikhoon, Mehdi Jamshidi Rastani, Somayeh Golbaz, Mehdi Fazlzadeh, Ramin Nabizadeh, Abbas Norouzian Baghani

Chemistry Faculty Publications

Solid waste components can be recycled in waste paper and cardboard sorting plants (WPCSP) through a multistep process. This work collected 15 samples every six days from each of the 9 points selected to study the processes taking place in a WPCSP (135 particulate matter samples total). Examining the concentration and size fraction of particulate matter (i.e., PM1, PM2.5 and PM10) in WPCSP is an essential issue to notify policy makers about the health impacts on exposed workers. The major activities for increasing of the concentration of PM in various processing units in the WPCSP, especially in hand-picking routes I …

Algorithm 1025: Paryopt: A Software For Parallel Asynchronous Remote Bayesian Optimization, Balaji Sesha Sarath Pokuri, Alec Lofquist, Chad Risko, Baskar Ganapathysubramanian

Chemistry Faculty Publications

PARyOpt is a Python based implementation of the Bayesian optimization routine designed for remote and asynchronous function evaluations. Bayesian optimization is especially attractive for computational optimization due to its low cost function footprint as well as the ability to account for uncertainties in data. A key challenge to efficiently deploy any optimization strategy on distributed computing systems is the synchronization step, where data from multiple function calls is assimilated to identify the next campaign of function calls. Bayesian optimization provides an elegant approach to overcome this issue via asynchronous updates. We formulate, develop and implement a parallel, asynchronous variant of …

Towards Upcycling Biomass-Derived Crosslinked Polymers With Light, Ravichandranath Singathi, Ramya Raghunathan, Retheesh Krishnan, Saravana Kumar Rajendran, Sruthy Baburaj, Mukund P. Sibi, Dean C. Webster, Jayaraman Sivaguru

Chemistry Faculty Publications

Photodegradable, recyclable, and renewable, crosslinked polymers from bioresources show promise towards developing a sustainable strategy to address the issue of plastics degradability and recyclability. Photo processes are not widely exploited for upcycling polymers in spite of the potential to have spatial and temporal control of the degradation in addition to being a green process. In this report we highlight a methodology in which biomass-derived crosslinked polymers can be programmed to degrade at ≈300 nm with ≈60 % recovery of the monomer. The recovered monomer was recycled back to the crosslinked polymer.

From Distinct To Differential Conformational Dynamics To Map Allosteric Communication Pathways In Proteins, Xin-Qiu Joe Yao, Donald Hamelberg

Chemistry Faculty Publications

Initiation of biological processes involving protein–ligand binding, transient protein–protein interactions, or amino acid modifications alters the conformational dynamics of proteins. Accompanying these biological processes are ensuing coupled atomic level conformational changes within the proteins. These conformational changes collectively connect multiple amino acid residues at distal allosteric, binding, and/or active sites. Local changes due to, for example, binding of a regulatory ligand at an allosteric site initiate the allosteric regulation. The allosteric signal propagates throughout the protein structure, causing changes at distal sites, activating, deactivating, or modifying the function of the protein. Hence, dynamical responses within protein structures to stimuli contain …

Chemical Thermodynamics—A Practical Wonderland, Rubin Battino, Trevor M. Letcher

Chemistry Faculty Publications

Chemical thermodynamics is frequently thought of as being a hard subject and quite abstract. In fact, it is one of the most practical of subjects when you consider that the field of chemical engineering (responsible for endless useful applications) is effectively applied chemical thermodynamics. In this essay, examples of these applications are given, especially with respect to sustainability. The essay first considers the limits of thermodynamics and the constraints put on it in terms of the rigorous definitions of the principal function’s energy, entropy, and Gibbs energy.

Characterization Of Mechanochemical Modification Of Porous Silicon With Arginine, Jacklyn A. Dipietro, Kurt W. Kolasinski

Chemistry Faculty Publications

Mechanochemistry initiated the reaction of hydrogen-terminated porous silicon (H/por-Si) powder with arginine. Samples were analyzed using Fourier-transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), zeta potential, scanning electron microscopy (SEM), and photoluminescence (PL) spectroscopy. Arginine, which was physisorbed onto the surface of por-Si, blue-shifted the peak PL intensity from similar to 630 nm for the H/por-Si to similar to 565 nm for arginine-coated por-Si. Grinding for 4 h reduced >80% of the initially 2-45 mu m particles to <500 nm, but was observed to quench the PL. With appropriate rinsing and centrifugation, particles in the 100 nm range were isolated. Rinsing ground powder with water was required to remove the unreacted arginine. Without rinsing, excess arginine induced the aggregation of passivated particles. However, water reacted with the freshly ground por-Si powder producing H-2. A zeta potential of +42 mV was measured for arginine-terminated por-Si particles dispersed in deionized water. This positive value was consistent with termination such that NH2 groups extended away from the surface. Furthermore, this result was confirmed by FTIR spectra, which suggested that arginine was bound to silicon through the formation of a covalent Si-O bond.

Computational Characterization Of Charge Transport Resiliency In Molecular Solids, Balaji Sesha Sarath Pokuri, Seab M. Ryno, Ramin Noruzi, Chad Risko, Baskar Ganapathysubramanian

Chemistry Faculty Publications

Organic semiconductors have found utility in a diverse array of applications. A key property impacting device performance is the charge transport mobility of the molecular solids making up the active layer in these devices. There is increasing interest in accessing, quantifying, and understanding the resilience of charge transport mobility to thermal, mechanical, and chemical perturbations in molecular solids. Here, we integrate molecular simulations with graph characterization to quantify the resilience of charge transport. We consider all-atom simulations of the PTB7 system and build on earlier graph approaches to rapidly characterize the charge mobility of the PTB7 molecular simulations. We introduce …

Network-Based Pharmacology Study Reveals Protein Targets For Medical Benefits And Harms Of Cannabinoids In Humans, Xingyu Li, Amit Madhukar Kudke, Felix Joseph Nepveux V, Yan Xu

Chemistry Faculty Publications

This network-based pharmacology study intends to uncover the underlying mechanisms of cannabis leading to a therapeutic benefit and the pathogenesis for a wide range of diseases claimed to benefit from or be caused by the use of the cannabis plant. Cannabis contains more than 600 chemical components. Among these components, cannabinoids are well-known to have multifarious pharmacological activities. In this work, twelve cannabinoids were selected as active compounds through text mining and drug-like properties screening and used for initial protein-target prediction. The disease-associated biological functions and pathways were enriched through GO and KEGG databases. Various biological networks [i.e., protein-protein interaction, …

All-Atom Simulations Uncover Structural And Dynamical Properties Of Sting Proteins In The Membrane System, Rachel Payne, Silvia Crivelli, Masakatsu Watanabe Ph.D.

Chemistry Faculty Publications

Recent studies have shown that the stimulator of interferon gene (STING) protein plays a central role in the immune system by facilitating the production of Type I interferons in cells. The STING signaling pathway is also a prominent activator of cancer-killing T cells that initiates a powerful adaptive immune response. Since biomolecular signaling pathways are complicated and not easily identified through traditional experiments, molecular dynamics (MD) has often been used to study these biological pathways’ structural and dynamical responses. Here, we carried out MD simulations for full-length chicken and human STING (chSTING and hSTING) proteins. Specifically, we investigated ligand-bound closed …

Characteristics And Assessing Biological Risks Of Airborne Bacteria In Waste Sorting Plant, Abbas Norouzian Baghani, Somayeh Golbaz, Gholamreza Ebrahimzadeh, Marcelo I. Guzman, Mahdieh Delikhoon, Mehdi Jamshidi Rastani, Abdullah Barkhordari, Ramin Nabizadeh

Chemistry Faculty Publications

Examining the concentration and types of airborne bacteria in waste paper and cardboard sorting plants (WPCSP) is an urgent matter to inform policy makers about the health impacts on exposed workers. Herein, we collected 20 samples at 9 points of a WPCSP every 6 winter days, and found that the most abundant airborne bacteria were positively and negatively correlated to relative humidity and temperature, respectively. The most abundant airborne bacteria (in units of CFU m⁻³) were: Staphylococcus sp. (72.4) > Micrococcus sp. (52.2) > Bacillus sp. (30.3) > Enterococcus sp. (24.0) > Serratia marcescens (20.1) > E. coli (19.1) > Pseudomonas sp. (16.0) > Nocardia …

Metabolic Features Of Brain Function With Relevance To Clinical Features Of Alzheimer And Parkinson Diseases, David Allan Butterfield, Maria Favia, Iolanda Spera, Annalisa Campanella, Martina Lanza, Alessandra Castegna

Chemistry Faculty Publications

Brain metabolism is comprised in Alzheimer’s disease (AD) and Parkinson’s disease (PD). Since the brain primarily relies on metabolism of glucose, ketone bodies, and amino acids, aspects of these metabolic processes in these disorders—and particularly how these altered metabolic processes are related to oxidative and/or nitrosative stress and the resulting damaged targets—are reviewed in this paper. Greater understanding of the decreased functions in brain metabolism in AD and PD is posited to lead to potentially important therapeutic strategies to address both of these disorders, which cause relatively long-lasting decreased quality of life in patients.

Residue–Residue Contact Changes During Functional Processes Define Allosteric Communication Pathways, Xin-Qiu Joe Yao, Donald Hamelberg

Chemistry Faculty Publications

Allosteric regulation plays a central role in orchestrating diverse cellular processes. A prerequisite for allostery is a flexible biomolecule within which two distal sites can communicate via concerted or sequential conformational changes. We introduce a computational method to elucidate allosteric communication pathways, comprising critical allosteric residues, in biomolecules by taking advantage of conformational changes during a functional process. Conformational changes are modeled explicitly since they modulate the network of residue–residue interactions, which could propagate allosteric signals between two or more distal sites. The method implements the suboptimal path analysis in the framework of the difference contact network analysis or dCNA. …

Synthesis Of Β,Β-Disubstituted Styrenes Via Trimethylsilyl Trifluoromethanesulfonate-Promoted Aldehyde-Aldehyde Aldol Addition-Deformylative Elimination., Grant J. Dixon, Michael R. Rodriguez, Tyler G. Chong, Kevin Y. Kim, C. Wade Downey

Chemistry Faculty Publications

In the presence of trimethylsilyl trifluoromethanesulfonate (TMSOTf) and 2,6-lutidine, α,α-disubstituted aldehydes condense with electron-rich aromatic aldehydes to yield β, β- disubstituted styrenes. More electron-rich aromatic aldehydes react more rapidly and in higher yield. Preliminary results suggest that the reaction may proceed via the ionization and formal deformylation of an aldol intermediate.

Visualizing Phytochemical-Protein Interaction Networks: Momordica Charantia And Cancer, Yumi L. Briones, Alexander T. Young, Fabian M. Dayrit, Armando Jerome De Jesus, Nina Rosario L. Rojas

Chemistry Faculty Publications

The in silico study of medicinal plants is a rapidly growing field. Techniques such as reverse screening and network pharmacology are used to study the complex cellular action of medicinal plants against disease. However, it is difficult to produce a meaningful visualization of phytochemical-protein interactions (PCPIs) in the cell. This study introduces a novel workflow combining various tools to visualize a PCPI network for a medicinal plant against a disease. The five steps are 1) phytochemical compilation, 2) reverse screening, 3) network building, 4) network visualization, and 5) evaluation. The output is a PCPI network that encodes multiple dimensions of …

Comparative Toxicity, Phytochemistry, And Use Of 53 Philippine Medicinal Plants, Lydia M. Clemen-Pascual, Rene Angelo S. Macahig, Nina Rosario L. Rojas

Chemistry Faculty Publications

The study compares the toxicity of 53 selected medicinal plants commonly used in the Philippines to treat various diseases. It uses as a benchmark Vitex negundo L., which was approved by the Philippine Food and Drug Administration as an herbal drug for cough and asthma after passing clinical trials for safety and efficacy. The methods were chosen for their simplicity and accessibility even for resource-limited laboratories. Extracts (95 % ethanol) of the medicinal parts of the plants were (1) chemically profiled using qualitative phytochemical tests that detect the presence of key classes of bioactive compounds; and (2) evaluated for toxicity …

A Tribute To Professor Gaetano Granozzi And His Contributions To Surface Science On The Occasion Of His 70th Birthday, Kurt W. Kolasinski

Chemistry Faculty Publications

On the occasion of his 70th birthday, we celebrate the career of our Editor-in-Chief, Professor Gaetano Granozzi. Prof. Granozzi’s work is marked by his dedication to the fundamental understanding of technologically relevant systems through the lens of surface science.

Aberrant Crosstalk Between Insulin Signaling And Mtor In Young Down Syndrome Individuals Revealed By Neuronal-Derived Extracellular Vesicles, Marzia Perluigi, Anna Picca, Elita Montanari, Riccardo Calvani, Federico Marini, Roberto Matassa, Antonella Tramutola, Alberto Villani, Giuseppe Familiari, Fabio Di Domenico, D. Allan Butterfield, Kenneth J. Oh, Emanuele Marzetti, Diletta Valentini, Eugenio Barone

Chemistry Faculty Publications

INTRODUCTION: Intellectual disability, accelerated aging, and early-onset Alzheimer-like neurodegeneration are key brain pathological features of Down syndrome (DS). Although growing research aims at the identification of molecular pathways underlying the aging trajectory of DS population, data on infants and adolescents with DS are missing.

METHODS: Neuronal-derived extracellular vesicles (nEVs) were isolated form healthy donors (HDs, n = 17) and DS children (n = 18) from 2 to 17 years of age and nEV content was interrogated for markers of insulin/mTOR pathways.

RESULTS: nEVs isolated from DS children were characterized by a significant increase in pIRS1^Ser636, a marker of …

Premade Nanoparticle Films For The Synthesis Of Vertically Aligned Carbon Nanotubes, Abdul Hoque, Ahamed Ullah, Beth S. Guiton, Noe T. Alvarez

Chemistry Faculty Publications

Carbon nanotubes (CNTs) offer unique properties that have the potential to address multiple issues in industry and material sciences. Although many synthesis methods have been developed, it remains difficult to control CNT characteristics. Here, with the goal of achieving such control, we report a bottom-up process for CNT synthesis in which monolayers of premade aluminum oxide (Al₂O₃) and iron oxide (Fe₃O₄) nanoparticles were anchored on a flat silicon oxide (SiO₂) substrate. The nanoparticle dispersion and monolayer assembly of the oleic-acid-stabilized Al₂O₃ nanoparticles were achieved using 11-phosphonoundecanoic acid …

Biotinylation As A Tool To Enhance The Uptake Of Small Molecules In Gram-Negative Bacteria, Ankit Pandeya, Ling Yang, Olaniyi Alegun, Chamikara Karunasena, Chad Risko, Zhenyu Li, Yinan Wei

Chemistry Faculty Publications

Antibiotic resistance is a major public health concern. The shrinking selection of effective antibiotics and lack of new development is making the situation worse. Gram-negative bacteria more specifically pose serious threat because of their double layered cell envelope and effective efflux systems, which is a challenge for drugs to penetrate. One promising approach to breach this barrier is the “Trojan horse strategy”. In this technique, an antibiotic molecule is conjugated with a nutrient molecule that helps the antibiotic to enter the cell through dedicated transporters for the nutrient. Here, we explored the approach using biotin conjugation with a florescent molecule …

The Primarily Undergraduate Nanomaterials Cooperative: A New Model For Supporting Collaborative Research At Small Institutions On A National Scale, Steven M. Huges, Mark P. Hendricks, Katherine M. Mullaugh, Mary E. Anderson, Anne K. Bently, Justin G. Clar, Clyde A. Daly Jr., Mark D. Ellison, Z. Vivian Feng, Natalia I. Gonzalex-Pech, Leslie S. Hamachi, Christine L. Heinecke, Joseph D. Keene, Adam M. Maley, Andrea M. Munro, Peter N. Njoki, Jacob H. Olshansky, Katherine E. Plass, Kathryn R. Riley, Matthew D. Sonntag, Sarah K. St. Angelo, Lucas B. Thompson, Emily J. Tollefson, Lauren E. Toote, Korin E. Wheeler

Chemistry Faculty Publications

The Primarily Undergraduate Nanomaterials Cooperative (PUNC) is an organization for research-active faculty studying nanomaterials at Primarily Undergraduate Institutions (PUIs), where undergraduate teaching and research go hand-in-hand. In this perspective, we outline the differences in maintaining an active research group at a PUI compared to an R1 institution. We also discuss the work of PUNC, which focuses on community building, instrument sharing, and facilitating new collaborations. Currently consisting of 37 members from across the United States, PUNC has created an online community consisting of its Web site (nanocooperative.org), a weekly online summer group meeting program for faculty and students, …

Evaluating Halogen-Bond Strength As A Function Of Molecular Structure Using Nuclear Magnetic Resonance Spectroscopy And Computational Analysis, Quang Minh Dang, Jeffrey H. Simpson, Carol A. Parish, Michael C. Leopold

Chemistry Faculty Publications

Halogen bonding (XB) is a highly directional, non-covalent intermolecular interaction between a molecule (XB donor) presenting a halogen with an electron-deficient region or sigma hole (σ-hole) and an electron-rich or Lewis-base molecule (XB acceptor). A systematic, experimental, and theoretical study of solution-phase XB strength as a function of the molecular structure for both XB donor and acceptor molecules is presented. The impact of specific structural features is assessed using ¹⁹F and ¹H nuclear magnetic resonance (NMR) titrations to determine association constants, density functional theory calculations for interaction energies and bond lengths, as well as ¹⁹F–¹H …

3d-Printable And Open-Source Modular Smartphone Visible Spectrophotometer, Brandon Winters, Nick Banfield, Cassandra Dixon, Anna Swensen, Dakota Holman, Braxton Fillbrown

Chemistry Faculty Publications

The past four decades have brought significant and increasingly rapid changes to the world of instrument design, fabrication, and availability due to the emergence of 3D printing, open-source code and equipment, and low-cost electronics. These, along with other technological advances represent a nexus in time ripe for the wide-spread production and availability of low-cost sophisticated scientific equipment. To that end, the design of a 3D printable and open-source, modular spectrometer is described. This specific instrument is distinctly different from others that have been reported in recent years in that it was designed outside of the “black box” paradigm of …

Aqueous Photochemistry Of 2-Oxocarboxylic Acids: Evidence, Mechanisms, And Atmospheric Impact, Marcelo I. Guzman, Alexis J. Eugene

Chemistry Faculty Publications

Atmospheric organic aerosols play a major role in climate, demanding a better understanding of their formation mechanisms by contributing multiphase chemical reactions with the participation of water. The sunlight driven aqueous photochemistry of small 2-oxocarboxylic acids is a potential major source of organic aerosol, which prompted the investigations into the mechanisms of glyoxylic acid and pyruvic acid photochemistry reviewed here. While 2-oxocarboxylic acids can be contained or directly created in the particles, the majorities of these abundant and available molecules are in the gas phase and must first undergo the surface uptake process to react in, and on the surface, …

Tuning Protein Dynamics To Sense Rapid Endoplasmic-Reticulum Calcium Dynamics, Xiaonan Deng, Xin-Qiu Joe Yao, Ken Berglund, Bin Dong, Daniel Ouedraogo, Mohammad A. Ghane, You Zhuo, Cheyenne Mcbean, Zheng Zachory Wei, Samer Gozem, Shan P. Yu, Ling Wei, Ning Fang, Angela M. Mabb, Giovanni Gadda, Donald Hamelberg, Jenny J. Yang

Chemistry Faculty Publications

Multi-scale calcium (Ca2+) dynamics, exhibiting wide-ranging temporal kinetics, constitutes a ubiquitous mode of signal transduction. We report a novel endoplasmic-reticulum (ER)-targeted Ca2+ indicator, R-CatchER, which showed superior kinetics in vitro (koff≥2×103 s−1, kon≥7×106 M−1 s−1) and in multiple cell types. R-CatchER captured spatiotemporal ER Ca2+ dynamics in neurons and hotspots at dendritic branchpoints, enabled the first report of ER Ca2+ oscillations mediated by calcium sensing receptors (CaSRs), and revealed ER Ca2+-based functional cooperativity of CaSR. We elucidate the mechanism of R-CatchER and propose a principle to rationally design genetically encoded Ca2+ indicators with a single Ca2+-binding site …

Fabrication Of Electrospun Nanofiber Composite Of G-C3n4 And Au Nanoparticles As Plasmonic Photocatalyst, Dipendu Saha, Pasquale Gismondi, Kurt W. Kolasinski, Samantha L. Shumlas, Sylvie Rangan, Babak Eslami, Amy Mcconnell, Taevaughn Bui, Kayla Cunfer

Chemistry Faculty Publications

In this research, we have fabricated a composite nanofiber mat of plasmonic photocatalyst consisting of g-C3N4, gold nanoparticles (AuNPs) and random nanofibers of polyvinylidene fluoride (PVDF) by electrospinning. The structure and chemical properties of the nanofiber mat were investigated in detail by ESEM, TEM, AFM, XPS, FTIR, XRD, TGA, PL spectroscopy and UV-Vis reflectance spectra. Imaging of the composite map confirmed that the fiber diameter was in the range of 100-400 nm with the g-C3N4 size in the range of 2-8 μm. Backscattered (Zcontrast) electron imaging in ESEM revealed that the AuNP particle size is in the range of 60-160 …

Structures Of Rhodopsin In Complex With G-Protein-Coupled Receptor Kinase 1, Qiuyan Chen, Manolo Plascencia, Zhuang Li, Somnath Mukherjee, Dhabaleswar Patra, Chun-Liang Chen, Thomas Klose, Xin-Qiu Joe Yao, Anthony A. Kossiakoff, Leifu Chang, Philip C. Andrews, John J.G. Tesmer

Chemistry Faculty Publications

G-protein-coupled receptor (GPCR) kinases (GRKs) selectively phosphorylate activated GPCRs, thereby priming them for desensitization1. Although it is unclear how GRKs recognize these receptors2,3,4, a conserved region at the GRK N terminus is essential for this process5,6,7,8. Here we report a series of cryo-electron microscopy single-particle reconstructions of light-activated rhodopsin (Rho*) bound to rhodopsin kinase (GRK1), wherein the N terminus of GRK1 forms a helix that docks into the open cytoplasmic cleft of Rho*. The helix also packs against the GRK1 kinase domain and stabilizes …