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Chm116 Principles Of Chemistry Ii Lecture Slides, Leah S. Cohen, Probal Banerjee May 2024

Chm116 Principles Of Chemistry Ii Lecture Slides, Leah S. Cohen, Probal Banerjee

Open Educational Resources

This file contains the lecture slides that are used in CHM116, Principles of Chemistry II.


Physics 422 Spring 2023 Syllabus - Medical Physics, Ronald Koder Apr 2023

Physics 422 Spring 2023 Syllabus - Medical Physics, Ronald Koder

Open Educational Resources

This is the Spring 2023 syllabus for Physics 315, Medical Physics, at CCNY


Physics 422 Spring 2023 Syllabus, Ronald Koder Apr 2023

Physics 422 Spring 2023 Syllabus, Ronald Koder

Open Educational Resources

Spring 2023 course syllabus for Physics 422, Biophysics, at the City College of New York


Raw Data Files For The Manuscript 'Elastin Recoil Is Driven By The Hydrophobic Effect', Nour M. Jamhawi, Ronald Koder, Richard J. Wittebort Jan 2023

Raw Data Files For The Manuscript 'Elastin Recoil Is Driven By The Hydrophobic Effect', Nour M. Jamhawi, Ronald Koder, Richard J. Wittebort

Publications and Research

These are the raw data files associated with the manuscript 'Elastin Recoil is Driven by the Hydrophobic Effect' by Nour M. Jamhawi, Ronald L. Koder, and Richard J. Wittebort


Inhibiting Glutamine Utilization Creates A Synthetic Lethality For Suppression Of Atp Citrate Lyase In Kras-Driven Cancer Cells, Ahmet Hatipoglu, Deepak Menon, Talia Levy, Maria A. Frias, David A. Foster Oct 2022

Inhibiting Glutamine Utilization Creates A Synthetic Lethality For Suppression Of Atp Citrate Lyase In Kras-Driven Cancer Cells, Ahmet Hatipoglu, Deepak Menon, Talia Levy, Maria A. Frias, David A. Foster

Publications and Research

Metabolic reprogramming is now considered a hallmark of cancer cells. KRas-driven cancer cells use glutaminolysis to generate the tricarboxylic acid cycle intermediate α -ketoglutarate via a transamination reaction between glutamate and oxaloacetate. We reported previously that exogenously supplied unsaturated fatty acids could be used to synthesize phosphatidic acid–a lipid second messenger that activates both mammalian target of rapamycin (mTOR) complex 1 (mTORC1) and mTOR complex 2 (mTORC2). A key target of mTORC2 is Akt–a kinase that promotes survival and regulates cell metabolism. We report here that mono- unsaturated oleic acid stimulates the phosphoryla tion of ATP citrate lyase (ACLY) at …


Small Molecule Modulation Of Microbiota: A Systems Pharmacology Perspective, Qiao Liu, Bohyun Lee, Lei Xie Sep 2022

Small Molecule Modulation Of Microbiota: A Systems Pharmacology Perspective, Qiao Liu, Bohyun Lee, Lei Xie

Publications and Research

Background

Microbes are associated with many human diseases and influence drug efficacy. Small-molecule drugs may revolutionize biomedicine by fine-tuning the microbiota on the basis of individual patient microbiome signatures. However, emerging endeavors in small-molecule microbiome drug discovery continue to follow a conventional “one-drug-one-target-one-disease” process. A systematic pharmacology approach that would suppress multiple interacting pathogenic species in the microbiome, could offer an attractive alternative solution.

Results

We construct a disease-centric signed microbe–microbe interaction network using curated microbe metabolite information and their effects on host. We develop a Signed Random Walk with Restart algorithm for the accurate prediction of effect of microbes …


Ten Steps To Organize A Virtual Scientific Symposium And Engage Your Global Audience, Jiye Son, Jasmine Sabio, Ankit Jain, Rein V. Ulijn Jun 2022

Ten Steps To Organize A Virtual Scientific Symposium And Engage Your Global Audience, Jiye Son, Jasmine Sabio, Ankit Jain, Rein V. Ulijn

Publications and Research

The paper describes guidelines for the planning, organization, and successful execution of virtual, global scientific conferences for global audiences. The guidelines are based on experience and lessons learned during the organization of the 3-day 2020 Virtual Systems Chemistry Symposium hosted on Zoom webinar and Twitter, held on May 2020 with over 1000 registered participants from 46 different countries.


Eukaryotic Initiation Factor 4f Promotes A Reorientation Of Eukaryotic Initiation Factor 3 Binding On The 5 And The 3 Utrs Of Barley Yellow Dwarf Virus Mrna, Paul Powell, Usha Bhardwaj, Dixie Goss Apr 2022

Eukaryotic Initiation Factor 4f Promotes A Reorientation Of Eukaryotic Initiation Factor 3 Binding On The 5 And The 3 Utrs Of Barley Yellow Dwarf Virus Mrna, Paul Powell, Usha Bhardwaj, Dixie Goss

Publications and Research

Viral mRNAs that lack a 5 m 7 GTP cap and a 3 poly-A tail rely on structural elements in their untranslated regions (UTRs) to form unique RNA-protein complexes that regulate viral translation. Recent studies of the barley yellow dwarf virus (BYDV) have revealed eukaryotic initiation factor 3 (eIF3) plays a significant role in facilitating communication be- tween its 5 and 3 UTRs by binding both UTRs simultaneously. This report uses in vitro translation assays, fluorescence anisotropy binding assays, and selective 2 -hydroxyl acylation analyzed by primer ex-tension (SHAPE) footprinting to identify secondary structures that are selectively interacting with eIF3. …


Glycocalyx Mechanotransduction Mechanisms Are Involved In Renal Cancer Metastasis, Heriberto Moran, Limary M. Cancel, Peigen Huang, Sylvie Roberge, Tuoye Xu, John M. Tarbell, Lance L. Munn Jan 2022

Glycocalyx Mechanotransduction Mechanisms Are Involved In Renal Cancer Metastasis, Heriberto Moran, Limary M. Cancel, Peigen Huang, Sylvie Roberge, Tuoye Xu, John M. Tarbell, Lance L. Munn

Publications and Research

Mammalian cells, including cancer cells, are covered by a surface layer containing cell bound proteoglycans, glycoproteins, associated glycosaminoglycans and bound proteins that is commonly referred to as the glycocalyx. Solid tumors also have a dynamic fluid microenvironment with elevated interstitial flow. In the present work we further investigate the hypothesis that interstitial flow is sensed by the tumor glycocalyx leading to activation of cell motility and metastasis. Using a highly metastatic renal carcinoma cell line (SN12L1) and its low metastatic counterpart (SN12C) we demonstrate in vitro that the small molecule Suberoylanilide Hydroxamic Acid (SAHA) inhibits the heparan sulfate synthesis enzyme …


Preparation For General Chemistry, Jose Cobo Jan 2022

Preparation For General Chemistry, Jose Cobo

Open Educational Resources

No abstract provided.


Principles Of General Chemistry, Jose Cobo Jan 2022

Principles Of General Chemistry, Jose Cobo

Open Educational Resources

No abstract provided.


High-Resolution Cryo-Electron Microscopy Structure Of Photosystem Ii From The Mesophilic Cyanobacterium, Synechocystis Sp. Pcc 6803, Christopher J. Gisriel, Jimin Wang, Jinchan Liu, David A. Flesher, Krystle M. Reiss, Hao-Li Huang, Ke R. Yang, William H. Armstrong, M. R. Gunner, Victor S. Batista, Richard J. Debus, Gary W. Brudvig Dec 2021

High-Resolution Cryo-Electron Microscopy Structure Of Photosystem Ii From The Mesophilic Cyanobacterium, Synechocystis Sp. Pcc 6803, Christopher J. Gisriel, Jimin Wang, Jinchan Liu, David A. Flesher, Krystle M. Reiss, Hao-Li Huang, Ke R. Yang, William H. Armstrong, M. R. Gunner, Victor S. Batista, Richard J. Debus, Gary W. Brudvig

Publications and Research

Photosystem II (PSII) enables global-scale, light-driven water oxidation. Genetic manipulation of PSII from the mesophilic cyanobacterium Synechocystis sp. PCC 6803 has provided insights into the mechanism of water oxidation; however, the lack of a highresolution structure of oxygen-evolving PSII from this organism has limited the interpretation of biophysical data to models based on structures of thermophilic cyanobacterial PSII. Here, we report the cryo-electron microscopy structure of PSII from Synechocystis sp. PCC 6803 at 1.93-Å resolution. A number of differences are observed relative to thermophilic PSII structures, including the following: the extrinsic subunit PsbQ is maintained, the C terminus of the …


Cryptococcus Neoformans Melanization Incorporates Multiple Catecholamines To Produce Polytypic Melanin, Rosanna P. Baker, Christine Chrissian, Ruth E. Stark, Arturo Casadevall Dec 2021

Cryptococcus Neoformans Melanization Incorporates Multiple Catecholamines To Produce Polytypic Melanin, Rosanna P. Baker, Christine Chrissian, Ruth E. Stark, Arturo Casadevall

Publications and Research

Melanin is a major virulence factor in pathogenic fungi that enhances the ability of fungal cells to resist immune clearance. Cryptococcus neoformans is an important human pathogenic fungus that synthesizes melanin from exogenous tissue catecholamine precursors during infection, but the type of melanin made in cryptococcal meningoencephalitis is unknown. We analyzed the efficacy of various catecholamines found in brain tissue in supporting melanization using animal brain tissue and synthetic catecholamine mixtures reflecting brain tissue proportions. Solid-state NMR spectra of the melanin pigment produced from such mixtures yielded more melanin than expected if only the preferred constituent dopamine had been incorporated, …


Structure Of A Monomeric Photosystem Ii Core Complex From A Cyanobacterium Acclimated To Far-Red Light Reveals The Functions Of Chlorophylls D And F, Christopher J. Gisriel, Gaozhong Shen, Ming-Yang Ho, Vasily Kurashov, David A. Flesher, Jimin Wang, William H. Armstrong, John H. Golbeck, Marilyn R. Gunner, David J. Vinyard, Richard J. Debus, Gary W. Brudvig, Donald A. Bryant Nov 2021

Structure Of A Monomeric Photosystem Ii Core Complex From A Cyanobacterium Acclimated To Far-Red Light Reveals The Functions Of Chlorophylls D And F, Christopher J. Gisriel, Gaozhong Shen, Ming-Yang Ho, Vasily Kurashov, David A. Flesher, Jimin Wang, William H. Armstrong, John H. Golbeck, Marilyn R. Gunner, David J. Vinyard, Richard J. Debus, Gary W. Brudvig, Donald A. Bryant

Publications and Research

Far-red light (FRL) photoacclimation in cyanobacteria provides a selective growth advantage for some terrestrial cyanobacteria by expanding the range of photosynthetically active radiation to include far-red/near-infrared light (700–800 nm). During this photoacclimation process, photosystem II (PSII), the water:plastoquinone photooxidoreductase involved in oxygenic photosynthesis, is modified. The resulting FRL-PSII is comprised of FRL-specific core subunits and binds chlorophyll (Chl) d and Chl f molecules in place of several of the Chl a molecules found when cells are grown in visible light. These new Chls effectively lower the energy canonically thought to define the “red limit” for light required to drive photochemical …


Cryo-Em Structure Of Mechanosensitive Channel Ynai Using Sma2000: Challenges And Opportunities, Claudio Catalano, Danya Ben-Hail, Weihua Qiu, Paul Blount, Amedee Des Georges, Youzhong Guo Oct 2021

Cryo-Em Structure Of Mechanosensitive Channel Ynai Using Sma2000: Challenges And Opportunities, Claudio Catalano, Danya Ben-Hail, Weihua Qiu, Paul Blount, Amedee Des Georges, Youzhong Guo

Publications and Research

Mechanosensitive channels respond to mechanical forces exerted on the cell membrane and play vital roles in regulating the chemical equilibrium within cells and their environment. Highresolution structural information is required to understand the gating mechanisms of mechanosensitive channels. Protein-lipid interactions are essential for the structural and functional integrity of mechanosensitive channels, but detergents cannot maintain the crucial native lipid environment for purified mechanosensitive channels. Recently, detergent-free systems have emerged as alternatives for membrane protein structural biology. This report shows that while membrane-active polymer, SMA2000, could retain some native cell membrane lipids on the transmembrane domain of the mechanosensitive-like YnaI channel, …


Expression, Purification And Refolding Of A Human Na V 1.7 Voltage Sensing Domain With Native-Like Toxin Binding Properties, Ryan V. Schroder, Leah S. Cohen, Ping Wang, Joekeem D. Arizala, Sébastien F. Poget Oct 2021

Expression, Purification And Refolding Of A Human Na V 1.7 Voltage Sensing Domain With Native-Like Toxin Binding Properties, Ryan V. Schroder, Leah S. Cohen, Ping Wang, Joekeem D. Arizala, Sébastien F. Poget

Publications and Research

The voltage-gated sodium channel NaV1.7 is an important target for drug development due to its role in pain perception. Recombinant expression of full-length channels and their use for biophysical characterization of interactions with potential drug candidates is challenging due to the protein size and complexity. To overcome this issue, we developed a protocol for the recombinant expression in E. coli and refolding into lipids of the isolated voltage sensing domain (VSD) of repeat II of NaV1.7, obtaining yields of about 2 mg of refolded VSD from 1 L bacterial cell culture. This VSD is known to be involved in the …


A Conserved Structural Role For The Walker-A Lysine In P-Loop Containing Kinases, Fatlum Hajredini, Ranajeet Ghose Oct 2021

A Conserved Structural Role For The Walker-A Lysine In P-Loop Containing Kinases, Fatlum Hajredini, Ranajeet Ghose

Publications and Research

Bacterial tyrosine kinases (BY-kinases) and shikimate kinases (SKs) comprise two structurally divergent P-loop containing enzyme families that share similar catalytic site geometries, most notably with respect to their Walker-A, Walker-B, and DxD motifs. We had previously demonstrated that in BY-kinases, a specific interaction between the Walker-A and Walker-B motifs, driven by the conserved “catalytic” lysine housed on the former, leads to a conformation that is unable to efficiently coordinate Mg2+•ATP and is therefore incapable of chemistry. Here, using enhanced sampling molecular dynamics simulations, we demonstrate that structurally similar interactions between the Walker-A and Walker-B motifs, also mediated by …


Aurora Kinase A Inhibition Reverses The Warburg Effect And Elicits Unique Metabolic Vulnerabilities In Glioblastoma, Trang T. T. Nguyen, Enyuan Shang, Chang Shu, Sungsoo Kim, Angeliki Mela, Nelson Humala, Aayushi Mahajan, Hee Won Yang, Hasan Orhan Akman, Catarina M. Quinzii, Guoan Zhang, Mike-Andrew Westhoff, Georg Karpel-Massler, Jeffrey N. Bruce, Peter Canoll, Markus D. Siegelin Sep 2021

Aurora Kinase A Inhibition Reverses The Warburg Effect And Elicits Unique Metabolic Vulnerabilities In Glioblastoma, Trang T. T. Nguyen, Enyuan Shang, Chang Shu, Sungsoo Kim, Angeliki Mela, Nelson Humala, Aayushi Mahajan, Hee Won Yang, Hasan Orhan Akman, Catarina M. Quinzii, Guoan Zhang, Mike-Andrew Westhoff, Georg Karpel-Massler, Jeffrey N. Bruce, Peter Canoll, Markus D. Siegelin

Publications and Research

Aurora kinase A (AURKA) has emerged as a drug target for glioblastoma (GBM). However, resistance to therapy remains a critical issue. By integration of transcriptome, chromatin immunoprecipitation sequencing (CHIP-seq), Assay for Transposase-Accessible Chromatin sequencing (ATAC-seq), proteomic and metabolite screening followed by carbon tracing and extracellular flux analyses we show that genetic and pharmacological AURKA inhibition elicits metabolic reprogramming mediated by inhibition of MYC targets and concomitant activation of Peroxisome Proliferator Activated Receptor Alpha (PPARA) signaling. While glycolysis is suppressed by AURKA inhibition, we note an increase in the oxygen consumption rate fueled by enhanced fatty acid oxidation (FAO), which was …


Decoding The Roles Of Astrocytes And Hedgehog Signaling In Medulloblastoma, Terence Teixeira Duarte, Silvia Aparecida Teixeira, Luis Gonzalez-Reyes, Rui Manuel Reis Aug 2021

Decoding The Roles Of Astrocytes And Hedgehog Signaling In Medulloblastoma, Terence Teixeira Duarte, Silvia Aparecida Teixeira, Luis Gonzalez-Reyes, Rui Manuel Reis

Publications and Research

The molecular evolution of medulloblastoma is more complex than previously imagined, as emerging evidence suggests that multiple interactions between the tumor cells and components of the tumor microenvironment (TME) are important for tumor promotion and progression. The identification of several molecular networks within the TME, which interact with tumoral cells, has provided new clues to understand the tumorigenic roles of many TME components as well as potential therapeutic targets. In this review, we discuss the most recent studies regarding the roles of astrocytes in supporting sonic hedgehog (SHH) subgroup medulloblastoma (MB) and provide an overview of MB progression through SHH …


Anatomy And Physiology Preparatory Course Textbook (2nd Edition), Carlos Liachovitzky Aug 2021

Anatomy And Physiology Preparatory Course Textbook (2nd Edition), Carlos Liachovitzky

Open Educational Resources

The goal of this preparatory textbook is to give students a chance to become familiar with some terms and some basic concepts they will find later on in the Anatomy and Physiology course, especially during the first few weeks of the course.

Organization and functioning of the human organism are generally presented starting from the simplest building blocks, and then moving into levels of increasing complexity. This textbook follows the same presentation. It begins introducing the concept of homeostasis, then covers the chemical level, and later on a basic introduction to cellular level, organ level, and organ system level. This …


Annotated Genome Sequence Of The High-Biomass-Producing Yellow-Green Alga Tribonema Minus, Kristina M. Mahan, Jüergen E.W. Polle, Zaid Mckie-Krisberg, Anna Lipzen, Alan Kuo, Igor V. Grigoriev, Todd W. Lane, Aubrey K. Davis Jun 2021

Annotated Genome Sequence Of The High-Biomass-Producing Yellow-Green Alga Tribonema Minus, Kristina M. Mahan, Jüergen E.W. Polle, Zaid Mckie-Krisberg, Anna Lipzen, Alan Kuo, Igor V. Grigoriev, Todd W. Lane, Aubrey K. Davis

Publications and Research

Here, we report the annotated genome sequence for a heterokont alga from the class Xanthophyceae. This high-biomass-producing strain, Tribonema minus UTEX B 3156, was isolated from a wastewater treatment plant in California. It is stable in outdoor raceway ponds and is a promising industrial feedstock for biofuels and bioproducts.


Protein Motifs For Proton Transfers That Build The Transmembrane Proton Gradient, Divya Kaur, Umesh Khaniya, Yingying Zhang, M. R. Gunner Jun 2021

Protein Motifs For Proton Transfers That Build The Transmembrane Proton Gradient, Divya Kaur, Umesh Khaniya, Yingying Zhang, M. R. Gunner

Publications and Research

Biological membranes are barriers to polar molecules, so membrane embedded proteins control the transfers between cellular compartments. Protein controlled transport moves substrates and activates cellular signaling cascades. In addition, the electrochemical gradient across mitochondrial, bacterial and chloroplast membranes, is a key source of stored cellular energy. This is generated by electron, proton and ion transfers through proteins. The gradient is used to fuel ATP synthesis and to drive active transport. Here the mechanisms by which protons move into the buried active sites of Photosystem II (PSII), bacterial RCs (bRCs) and through the proton pumps, Bacteriorhodopsin (bR), Complex I and Cytochrome …


Control Of Pre-Replicative Complex During The Division Cycle In Chlamydomonas Reinhardtii, Amy E. Ikui, Noriko Ueki, Kresti Pecani, Frederick R. Cross Apr 2021

Control Of Pre-Replicative Complex During The Division Cycle In Chlamydomonas Reinhardtii, Amy E. Ikui, Noriko Ueki, Kresti Pecani, Frederick R. Cross

Publications and Research

DNA replication is fundamental to all living organisms. In yeast and animals, it is triggered by an assembly of pre-replicative complex including ORC, CDC6 and MCMs. Cyclin Dependent Kinase (CDK) regulates both assembly and firing of the pre-replicative complex. We tested temperature-sensitive mutants blocking Chlamydomonas DNA replication. The mutants were partially or completely defective in DNA replication and did not produce mitotic spindles. After a long G1, wild type Chlamydomonas cells enter a division phase when it undergoes multiple rapid synchronous divisions (‘multiple fission’). Using tagged transgenic strains, we found that MCM4 and MCM6 were localized to the nucleus throughout …


Lighting The Way: Recent Insights Into The Structure And Regulation Of Phototropin Blue Light Receptors, Jaynee E. Hart, Kevin H. Gardner Mar 2021

Lighting The Way: Recent Insights Into The Structure And Regulation Of Phototropin Blue Light Receptors, Jaynee E. Hart, Kevin H. Gardner

Publications and Research

The phototropins (phots) are light-activated kinases that are critical for plant physiology and the many diverse optogenetic tools that they have inspired. Phototropins combine two bluelight- sensing Light–Oxygen–Voltage (LOV) domains (LOV1 and LOV2) and a C-terminal serine/threonine kinase domain, using the LOV domains to control the catalytic activity of the kinase. While much is known about the structure and photochemistry of the light-perceiving LOV domains, particularly in how activation of the LOV2 domain triggers the unfolding of alpha helices that communicate the light signal to the kinase domain, many questions about phot structure and mechanism remain. Recent studies have made …


Single-Cell Fluidic Force Microscopy Reveals Stress- Dependent Molecular Interactions In Yeast Mating, Marion Mathelié-Guinlet, Felipe Viela, JéRôMe Dehullu, Sviatlana Filimonava, Jason M. Rauceo, Peter N. Lipke, Yves F. DufrêNe Jan 2021

Single-Cell Fluidic Force Microscopy Reveals Stress- Dependent Molecular Interactions In Yeast Mating, Marion Mathelié-Guinlet, Felipe Viela, JéRôMe Dehullu, Sviatlana Filimonava, Jason M. Rauceo, Peter N. Lipke, Yves F. DufrêNe

Publications and Research

Sexual agglutinins of the budding yeast Saccharomyces cerevisiae are proteins mediating cell aggregation during mating. Complementary agglutinins expressed by cells of opposite mating types “a” and “α” bind together to promote agglutination and facilitate fusion of haploid cells. By means of an innovative single-cell manipulation assay combining fluidic force microscopy with force spectroscopy, we unravel the strength of single specific bonds between a- and α-agglutinins (~100 pN) which require pheromone induction. Prolonged cell–cell contact strongly increases adhesion between mating cells, likely resulting from an increased expression of agglutinins. In addition, we highlight the critical role of disulfide bonds of the …


Enzymatic Analysis Of Yeast Cell Wall-Resident Gapdh And Its Secretion, Michael J. Cohen, Brianne Philippe, Peter N. Lipke Dec 2020

Enzymatic Analysis Of Yeast Cell Wall-Resident Gapdh And Its Secretion, Michael J. Cohen, Brianne Philippe, Peter N. Lipke

Publications and Research

In yeast, many proteins are found in both the cytoplasmic and extracellu- lar compartments, and consequently it can be difficult to distinguish nonconventional secretion from cellular leakage. Therefore, we monitored the extracellular glyceralde- hyde-3-phosphate dehydrogenase (GAPDH) activity of intact cells as a specific marker for nonconventional secretion. Extracellular GAPDH activity was proportional to the number of cells assayed, increased with incubation time, and was dependent on added substrates. Preincubation of intact cells with 100mM dithiothreitol increased the reac- tion rate, consistent with increased access of the enzyme after reduction of cell wall di- sulfide cross-links. Such treatment did not increase …


Unconventional Constituents And Shared Molecular Architecture Of The Melanized Cell Wall Of C. Neoformans And Spore Wall Of S. Cerevisiae, Christine Chrissian, Coney Pei-Chin Lin, Emma Camacho, Arturo Casadevall, Aaron M. Neiman, Ruth E. Stark Dec 2020

Unconventional Constituents And Shared Molecular Architecture Of The Melanized Cell Wall Of C. Neoformans And Spore Wall Of S. Cerevisiae, Christine Chrissian, Coney Pei-Chin Lin, Emma Camacho, Arturo Casadevall, Aaron M. Neiman, Ruth E. Stark

Publications and Research

The fungal cell wall serves as the interface between the cell and the environment. Fungal cell walls are composed largely of polysaccharides, primarily glucans and chitin, though in many fungi stress-resistant cell types elaborate additional cell wall structures. Here, we use solid-state nuclear magnetic resonance spectroscopy to compare the architecture of cell wall fractions isolated from Saccharomyces cerevisiae spores and Cryptococcus neoformans melanized cells. The specialized cell walls of these two divergent fungi are highly similar in composition. Both use chitosan, the deacetylated derivative of chitin, as a scaffold on which a polyaromatic polymer, dityrosine and melanin, respectively, is assembled. …


Two And Three-Dimensional Radiographic Imaging Of Contrast Agents In Heterogeneous Live Cell Media To Understand Contrast-Induced Toxicity, Fahaneda Hassan, Aldona Gjoni, Subhendra Sarkar Oct 2020

Two And Three-Dimensional Radiographic Imaging Of Contrast Agents In Heterogeneous Live Cell Media To Understand Contrast-Induced Toxicity, Fahaneda Hassan, Aldona Gjoni, Subhendra Sarkar

Publications and Research

Radiographic imaging was done using low and high energy radiography equipment. The test hypothesis that macromolecular aggregation changes sample noise in imaging samples for optical imaging methods. Inorganic complexes scatter radiation at the molecular level and may increase the sample noise locally. At high and low photon energies in various x-ray machines, sample and background noise were gathered and compared with those from mammography systems from mammography researchers. The samples with high macromolecular aggregates were prepared using various animal cell compositions and imaged under different conditions that produced different macromolecular dynamics within the samples and thus different image-based sample noise. …


3,7-Dihydroxytropolones Inhibit Initiation Of Hepatitis B Virus Minus-Strand Dna Synthesis, Ellen Bak, Jennifer T. Miller, Andrea Noronha, John Tavis, Emilio Gallicchio, Ryan P. Murelli, Stuart F. J. Le Grice Sep 2020

3,7-Dihydroxytropolones Inhibit Initiation Of Hepatitis B Virus Minus-Strand Dna Synthesis, Ellen Bak, Jennifer T. Miller, Andrea Noronha, John Tavis, Emilio Gallicchio, Ryan P. Murelli, Stuart F. J. Le Grice

Publications and Research

Initiation of protein-primed (-) strand DNA synthesis in hepatitis B virus (HBV) requires interaction of the viral reverse transcriptase with epsilon (ε), a cis-acting regulatory signal located at the 5’ terminus of pre-genomic RNA (pgRNA), and several host-encoded chaperone proteins. Binding of the viral polymerase (P protein) to ε is necessary for pgRNA encapsidation and synthesis of a short primer covalently attached to its terminal domain. Although we identified small molecules that recognize HBV ε RNA, these failed to inhibit protein-primed DNA synthesis. However, since initiation of HBV (-) strand DNA synthesis occurs within a complex of viral and host …


Retrieving Functional Pathways Of Biomolecules From Single-Particle Snapshots, Ali Dashti, Ghoncheh Mashayekhi, Mrinal Shekhar, Danya Ben Hail, Salah Salah, Peter Schwander, Amedee Des Georges, Abhishek Singharoy, Joachim Frank, Abbas Ourmazd Sep 2020

Retrieving Functional Pathways Of Biomolecules From Single-Particle Snapshots, Ali Dashti, Ghoncheh Mashayekhi, Mrinal Shekhar, Danya Ben Hail, Salah Salah, Peter Schwander, Amedee Des Georges, Abhishek Singharoy, Joachim Frank, Abbas Ourmazd

Publications and Research

A primary reason for the intense interest in structural biology is the fact that knowledge of structure can elucidate macromolecular functions in living organisms. Sustained effort has resulted in an impressive arsenal of tools for determining the static structures. But under physiological conditions, macromolecules undergo continuous conformational changes, a subset of which are functionally important. Techniques for capturing the continuous conformational changes underlying function are essential for further progress. Here, we present chemically-detailed conformational movies of biological function, extracted data-analytically from experimental single-particle cryo-electron microscopy (cryo-EM) snapshots of ryanodine receptor type 1 (RyR1), a calcium-activated calcium channel engaged in the …