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Articles 1 - 19 of 19

Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

A Thermophilic Phage Uses A Small Terminase Protein With A Fixed Helix-Turn-Helix Geometry, Janelle A. Hayes, Brendan J. Hilbert, Christl Gaubitz, Nicholas P. Stone, Brian A. Kelch Nov 2019

A Thermophilic Phage Uses A Small Terminase Protein With A Fixed Helix-Turn-Helix Geometry, Janelle A. Hayes, Brendan J. Hilbert, Christl Gaubitz, Nicholas P. Stone, Brian A. Kelch

University of Massachusetts Medical School Faculty Publications

Tailed bacteriophage use a DNA packaging motor to encapsulate their genome during viral particle assembly. The small terminase (TerS) component acts as a molecular matchmaker by recognizing the viral genome as well as the main motor component, the large terminase (TerL). How TerS binds DNA and the TerL protein remains unclear. Here, we identify the TerS protein of the thermophilic bacteriophage P74-26. TerSP76-26 oligomerizes into a nonamer that binds DNA, stimulates TerL ATPase activity, and inhibits TerL nuclease activity. Our cryo-EM structure shows that TerSP76-26 forms a ring with a wide central pore and radially arrayed helix-turn-helix (HTH ...


Developing Tale Proteins As A Biosensor For Detecting Pathogen Specific Double-Stranded Dna, Kathrine Gaiko Apr 2019

Developing Tale Proteins As A Biosensor For Detecting Pathogen Specific Double-Stranded Dna, Kathrine Gaiko

Honors College Capstone Experience/Thesis Projects

Transcription activator-like effector (TALE) proteins are important for DNA binding. They bind to specific nucleotide sequences by the use of two residues in each repeat allowing them to target specific DNA sequences. Their modular structure makes TALEs advantageous over other DNA binding proteins such as zinc finger proteins. Zinc finger proteins (ZFP) use a finger like projection to bind 3-4 subsequence base pairs while TALE proteins use two amino acid residues in each repeat to bind one nucleotide. ZFP can use SEER-Lac system for colorimetric detection, while TALE proteins can use fluorescence labeling with Alexa for detection of binding to ...


The Trim-Nhl Protein Nhl-2 Is A Novel Co-Factor Of The Csr-1 And Hrde-1 22g-Rna Pathways, Peter R. Boag, Gregory M. Davis, Shikui Tu, Rhys N. Colson, Joshua W. T. Anderson, Menachem J. Gunzburg, Michelle A. Francisco, Debashish Ray, Tuhin Maity, Monica Z. Wu, Quaid D. Morris, Timothy R. Hughes, Jacqueline A. Wilce, University Of Toronto, Zhiping Weng Feb 2018

The Trim-Nhl Protein Nhl-2 Is A Novel Co-Factor Of The Csr-1 And Hrde-1 22g-Rna Pathways, Peter R. Boag, Gregory M. Davis, Shikui Tu, Rhys N. Colson, Joshua W. T. Anderson, Menachem J. Gunzburg, Michelle A. Francisco, Debashish Ray, Tuhin Maity, Monica Z. Wu, Quaid D. Morris, Timothy R. Hughes, Jacqueline A. Wilce, University Of Toronto, Zhiping Weng

University of Massachusetts Medical School Faculty Publications

Proper regulation of germline gene expression is essential for fertility and maintaining species integrity. In the C. elegans germline, a diverse repertoire of regulatory pathways promote the expression of endogenous germline genes and limit the expression of deleterious transcripts to maintain genome homeostasis. Here we show that the conserved TRIM-NHL protein, NHL-2, plays an essential role in the C. elegans germline, modulating germline chromatin and meiotic chromosome organization. We uncover a role for NHL-2 as a co-factor in both positively (CSR-1) and negatively (HRDE-1) acting germline 22G-small RNA pathways and the somatic nuclear RNAi pathway. Furthermore, we demonstrate that NHL-2 ...


Automatic Animation Of Molecular Motion Using Python And Cinema 4d, Diana Zajac, Nathaniel Smith, Dan Gurnon Nov 2014

Automatic Animation Of Molecular Motion Using Python And Cinema 4d, Diana Zajac, Nathaniel Smith, Dan Gurnon

Science Research Fellows Posters

No abstract provided.


Stoichiometries And Affinities Of Interacting Proteins From Concentration Series Of Solution Scattering Data: Decomposition By Least Squares And Quadratic Optimization, Himanshu Chandola, Tim E. Williamson, Bruce A. Craig, Alan M. Friedman, Chris Bailey-Kellogg Mar 2014

Stoichiometries And Affinities Of Interacting Proteins From Concentration Series Of Solution Scattering Data: Decomposition By Least Squares And Quadratic Optimization, Himanshu Chandola, Tim E. Williamson, Bruce A. Craig, Alan M. Friedman, Chris Bailey-Kellogg

Open Dartmouth: Faculty Open Access Scholarship

In studying interacting proteins, complementary insights are provided by analyzing both the association model (the stoichiometry and affinity constants of the intermediate and final complexes) and the quaternary structure of the resulting complexes. Many current methods for analyzing protein interactions either give a binary answer to the question of association and no information about quaternary structure or at best provide only part of the complete picture. Presented here is a method to extract both types of information from X-ray or neutron scattering data for a series of equilibrium mixtures containing the initial components at different concentrations. The method determines the ...


Computational De Novo Design And Characterization Of A Protein That Selectively Binds A Highly Hyperpolarizable Abiological Chromophore, H Christopher Fry, Andreas Lehmann, Louise E. Sinks, Inge Asselberghs, Andrey Tronin, Venkata Krishnan, J Kent Blasie, Koen Clays, William F. Degrado, Jeffery G. Saven, Michael J. Therien Sep 2013

Computational De Novo Design And Characterization Of A Protein That Selectively Binds A Highly Hyperpolarizable Abiological Chromophore, H Christopher Fry, Andreas Lehmann, Louise E. Sinks, Inge Asselberghs, Andrey Tronin, Venkata Krishnan, J Kent Blasie, Koen Clays, William F. Degrado, Jeffery G. Saven, Michael J. Therien

Departmental Papers (Chemistry)

This work reports the first example of a single-chain protein computationally designed to contain four α-helical segments and fold to form a four-helix bundle encapsulating a supramolecular abiological chromophore that possesses exceptional nonlinear optical properties. The 109-residue protein, designated SCRPZ-1, binds and disperses an insoluble hyperpolarizable chromophore, ruthenium(II) [5-(4'-ethynyl-(2,2';6',2″-terpyridinyl))-10,20-bis(phenyl)porphinato]zinc(II)-(2,2';6',2″-terpyridine)(2+) (RuPZn) in aqueous buffer solution at a 1:1 stoichiometry. A 1:1 binding stoichiometry of the holoprotein is supported by electronic absorption and circular dichroism spectra, as well as equilibrium ...


Utilizing Nmr Spectroscopy And Molecular Docking As Tools For The Structural Determination And Functional Annotation Of Proteins, Jaime Stark Feb 2013

Utilizing Nmr Spectroscopy And Molecular Docking As Tools For The Structural Determination And Functional Annotation Of Proteins, Jaime Stark

Student Research Projects, Dissertations, and Theses - Chemistry Department

With the completion of the Human Genome Project in 2001 and the subsequent explosion of organisms with sequenced genomes, we are now aware of nearly 28 million proteins. Determining the role of each of these proteins is essential to our understanding of biology and the development of medical advances. Unfortunately, the experimental approaches to determine protein function are too slow to investigate every protein. Bioinformatics approaches, such as sequence and structure homology, have helped to annotate the functions of many similar proteins. However, despite these computational approaches, approximately 40% of proteins still have no known function. Alleviating this deficit will ...


Secondary Structure, A Missing Component Of Sequence- Based Minimotif Definitions, David P. Sargeant, Michael R. Gryk, Mark W. Maciejewsk, Vishal Thapar, Vamsi Kundeti, Sanguthevar Rajasekaran, Pedro Romero, Keith Dunker, Shun-Cheng Li, Tomonori Kaneko, Martin Schiller Dec 2012

Secondary Structure, A Missing Component Of Sequence- Based Minimotif Definitions, David P. Sargeant, Michael R. Gryk, Mark W. Maciejewsk, Vishal Thapar, Vamsi Kundeti, Sanguthevar Rajasekaran, Pedro Romero, Keith Dunker, Shun-Cheng Li, Tomonori Kaneko, Martin Schiller

Life Sciences Faculty Publications

Minimotifs are short contiguous segments of proteins that have a known biological function. The hundreds of thousands of minimotifs discovered thus far are an important part of the theoretical understanding of the specificity of protein-protein interactions, posttranslational modifications, and signal transduction that occur in cells. However, a longstanding problem is that the different abstractions of the sequence definitions do not accurately capture the specificity, despite decades of effort by many labs. We present evidence that structure is an essential component of minimotif specificity, yet is not used in minimotif definitions. Our analysis of several known minimotifs as case studies, analysis ...


Juvenile Hormone Regulates Vitellogenin Gene Expression Through Insulin-Like Peptide Signaling Pathway In The Red Flour Beetle, Tribolium Castaneum, Zhentao Sheng, Jingjing Xu, Hua Bai, Fang Zhu, Subba R. Palli Dec 2011

Juvenile Hormone Regulates Vitellogenin Gene Expression Through Insulin-Like Peptide Signaling Pathway In The Red Flour Beetle, Tribolium Castaneum, Zhentao Sheng, Jingjing Xu, Hua Bai, Fang Zhu, Subba R. Palli

Entomology Faculty Publications

Our recent studies identified juvenile hormone (JH) and nutrition as the two key signals that regulate vitellogenin (Vg) gene expression in the red flour beetle, Tribolium castaneum. Juvenile hormone regulation of Vg synthesis has been known for a long time in several insects, but the mechanism of JH action is not known. Experiments were conducted to determine the mechanism of action of these two signals in regulation of Vg gene expression. Injection of bovine insulin or FOXO double-stranded RNA into the previtellogenic, starved, or JH-deficient female adults increased Vg mRNA and protein levels, thereby implicating the pivotal role for insulin-like ...


Planning Combinatorial Disulfide Cross-Links For Protein Fold Determination, Fei Xiong, Alan M Friedman, Chris Bailey-Kellogg Nov 2011

Planning Combinatorial Disulfide Cross-Links For Protein Fold Determination, Fei Xiong, Alan M Friedman, Chris Bailey-Kellogg

Open Dartmouth: Faculty Open Access Scholarship

Fold recognition techniques take advantage of the limited number of overall structural organizations, and have become increasingly effective at identifying the fold of a given target sequence. However, in the absence of sufficient sequence identity, it remains difficult for fold recognition methods to always select the correct model. While a native-like model is often among a pool of highly ranked models, it is not necessarily the highest-ranked one, and the model rankings depend sensitively on the scoring function used. Structure elucidation methods can then be employed to decide among the models based on relatively rapid biochemical/biophysical experiments.


Computational Protein Design: Engineering Molecular Diversity, Nonnatural Enzymes, Nonbiological Cofactor Complexes, And Membrane Proteins, Jeffery G. Saven Jun 2011

Computational Protein Design: Engineering Molecular Diversity, Nonnatural Enzymes, Nonbiological Cofactor Complexes, And Membrane Proteins, Jeffery G. Saven

Departmental Papers (Chemistry)

Computational and theoretical methods are advancing protein design as a means to create and investigate proteins. Such efforts further our capacity to control, design and understand biomolecular structure, sequence and function. Herein, the focus is on some recent applications that involve using theoretical and computational methods to guide the design of protein sequence ensembles, new enzymes, proteins with novel cofactors, and membrane proteins.


Targeted Identification Of Metastasis-Associated Cell-Surface Sialoglycoproteins In Prostate Cancer, Lifang Yang, Julius O. Nyalwidhe, Sigi Guo, Richard R. Drake, O. John Semmes Jan 2011

Targeted Identification Of Metastasis-Associated Cell-Surface Sialoglycoproteins In Prostate Cancer, Lifang Yang, Julius O. Nyalwidhe, Sigi Guo, Richard R. Drake, O. John Semmes

Bioelectrics Publications

Covalent attachment of carbohydrates to proteins is one of the most common post-translational modifications. At the cell surface, sugar moieties of glycoproteins contribute to molecular recognition events involved in cancer metastasis. We have combined glycan metabolic labeling with mass spectrometry analysis to identify and characterize metastasis-associated cell surface sialoglycoproteins. Our model system used syngeneic prostate cancer cell lines derived from PC3 (N2, nonmetastatic, and ML2, highly metastatic). The metabolic incorporation of AC4ManNAz and subsequent specific labeling of cell surface sialylation was confirmed by flow cytometry and confocal microscopy. Affinity isolation of the modified sialic-acid containing cell surface proteins ...


Computational Design And Elaboration Of A De Novo Heterotetrameric Α-Helical Protein That Selectively Binds An Emissive Abiological (Porphinato)Zinc Chromophore, H Christopher Fry, Andreas Lehmann, Jeffery G. Saven, William F. Degrado, Michael J. Therien Mar 2010

Computational Design And Elaboration Of A De Novo Heterotetrameric Α-Helical Protein That Selectively Binds An Emissive Abiological (Porphinato)Zinc Chromophore, H Christopher Fry, Andreas Lehmann, Jeffery G. Saven, William F. Degrado, Michael J. Therien

Departmental Papers (Chemistry)

The first example of a computationally de novo designed protein that binds an emissive abiological chromophore is presented, in which a sophisticated level of cofactor discrimination is pre-engineered. This heterotetrameric, C(2)-symmetric bundle, A(His):B(Thr), uniquely binds (5,15-di[(4-carboxymethyleneoxy)phenyl]porphinato)zinc [(DPP)Zn] via histidine coordination and complementary noncovalent interactions. The A(2)B(2) heterotetrameric protein reflects ligand-directed elements of both positive and negative design, including hydrogen bonds to second-shell ligands. Experimental support for the appropriate formulation of [(DPP)Zn:A(His):B(Thr)](2) is provided by UV/visible and circular dichroism spectroscopies ...


Nip/Duoxa Is Essential For Drosophila Embryonic Development And Regulates Oxidative Stress Response., Xiaojun Xie, Jack Hu, Xiping Liu, Hanjuan Qin, Anthony Percival-Smith, Yong Rao, Shawn S C Li Jan 2010

Nip/Duoxa Is Essential For Drosophila Embryonic Development And Regulates Oxidative Stress Response., Xiaojun Xie, Jack Hu, Xiping Liu, Hanjuan Qin, Anthony Percival-Smith, Yong Rao, Shawn S C Li

Biochemistry Publications

NIP/DuoxA, originally cloned as a protein capable of binding to the cell fate determinant Numb in Drosophila, was recently identified as a modulator of reactive oxygen species (ROS) production in mammalian systems. Despite biochemical and cellular studies that link NIP/DuoxA to the generation of ROS through the dual oxidase (Duox) enzyme, the in vivo function of NIP/DuoxA has not been characterized to date. Here we report a genetic and functional characterization of nip in Drosophila melanogaster. We show that nip is essential for Drosophila development as nip null mutants die at the 1(st) larval instar. Expression ...


A New N-Terminal Recognition Domain In Caveolin-1 Interacts With Sterol Carrier Protein-2 (Scp-2), Rebecca D. Parr, Gregory G. Martin, Heather A. Hostetler, Megan E. Schroeder, Kiran D. Mir, Ann B. Kier, Judith M. Ball, Friedhelm Schroeder Jan 2007

A New N-Terminal Recognition Domain In Caveolin-1 Interacts With Sterol Carrier Protein-2 (Scp-2), Rebecca D. Parr, Gregory G. Martin, Heather A. Hostetler, Megan E. Schroeder, Kiran D. Mir, Ann B. Kier, Judith M. Ball, Friedhelm Schroeder

Faculty Publications

Although plasma membrane domains, such as caveolae, provide an organizing principle for signaling pathways and cholesterol homeostasis in the cell, relatively little is known regarding specific mechanisms, whereby intracellular lipid-binding proteins are targeted to caveolae. Therefore, the interaction between caveolin-1 and sterol carrier protein-2 (SCP-2), a protein that binds and transfers both cholesterol and signaling lipids (e.g., phosphatidylinositides and sphingolipids), was examined by yeast two-hybrid, in vitro binding and fluorescence resonance energy transfer (FRET) analyses. Results of the in vivo and in vitro assays identified for the first time the N-terminal amino acids (aa) 1−32 amphipathic α helix ...


Thermal And Sodium Dodecylsulfate Induced Transitions Of Streptavidin, Mark J. Waner, Irina Navrotskaya, Amanda Bain, Edward D. Oldham, David P. Mascotti Oct 2004

Thermal And Sodium Dodecylsulfate Induced Transitions Of Streptavidin, Mark J. Waner, Irina Navrotskaya, Amanda Bain, Edward D. Oldham, David P. Mascotti

Chemistry

The strong specific binding of streptavidin (SA) to biotin is utilized in numerous biotechnological applications. The SA tetramer is also known to exhibit significant stability, even in the presence of sodium dodecylsulfate (SDS). Despite its importance, relatively little is known about the nature of the thermal denaturation pathway for SA. This work uses a homogeneous SA preparation to expand on the data of previous literature reports, leading to the proposal of a model for temperature induced structural changes in SA. Temperature dependent data were obtained by SDS and native polyacrylamide gel electrophoresis (PAGE), differential scanning calorimetry (DSC), and fluorescence and ...


Effects Of Distal Pocket Mutations On The Geminate Recombination Of No With Leghemoglobin On The Picosecond Time Scale, Pramit Kumar Chowdhury, S. Kundu, Mintu Halder, K. Das, Mark S. Hargrove, Jacob W. Petrich Aug 2003

Effects Of Distal Pocket Mutations On The Geminate Recombination Of No With Leghemoglobin On The Picosecond Time Scale, Pramit Kumar Chowdhury, S. Kundu, Mintu Halder, K. Das, Mark S. Hargrove, Jacob W. Petrich

Chemistry Publications

The picosecond NO geminate rebinding kinetics of wild-type leghemoglobin, a monomeric plant hemoglobin with structural similarity to myoglobin, and six mutant proteins at the distal histidine (H61G, H61A, H61V, H61L, H61R, H61F) are investigated. All of the mutant proteins yield rebinding kinetics that are initially more rapid than that of the wild-type protein. At long times, the rebinding of H61F becomes slower than that of wild-type leghemoglobin. The H61V, H61L, and H61G mutant proteins give extraordinarily rapid and complete geminate rebinding. On a 40 ps time scale, distal effects are overwhelmingly evident for all of the mutants considered. That binding ...


Acetylation Of Synaptosomal Protein: Inhibition Of Veratridine / Soll Berl, Ramiro Nunez, Arlene D. Colon, And Donald D. Clarke Mount Sinai School Of Medicine, And Chemistry Department, Fordham University, New York, New York, U.S.A., Soll Berl, Ramiro Nunez, Arlene D. Colon, Donald Dudley Clarke Phd Jan 1983

Acetylation Of Synaptosomal Protein: Inhibition Of Veratridine / Soll Berl, Ramiro Nunez, Arlene D. Colon, And Donald D. Clarke Mount Sinai School Of Medicine, And Chemistry Department, Fordham University, New York, New York, U.S.A., Soll Berl, Ramiro Nunez, Arlene D. Colon, Donald Dudley Clarke Phd

Chemistry Faculty Publications

Incubation of synaptosomes with [3H]acetate results in rapid labeling of protein. Labeling is decreased in the presence of veratridine, and the effect of veratridine is blocked by tetrodotoxin. Most of the radioactivity can be removed by base or acid hydrolysis, and is probably incorporated as acetate; it is this fraction that is affected by the veratridine. The data suggest that veratridine stimulates deacetylation of synaptosomal protein. This raises the question whether acetylation-deacetylation is involved in membrane function


Nonenzymatic Glycosylation Of Erythrocyte Membrane Proteins. Relevance To Diabetes, J A. Miller, Ellen M. Gravallese, H F. Bunn Apr 1980

Nonenzymatic Glycosylation Of Erythrocyte Membrane Proteins. Relevance To Diabetes, J A. Miller, Ellen M. Gravallese, H F. Bunn

Rheumatology Publications and Presentations

Nonenzymatic glycosylation of proteins of the erythrocyte membrane was determined by incubating erythrocyte ghosts with [3H]borohydride. The incorporation of tritium into protein provides a reliable assay of ketoamine linkages. The membrane proteins from 18 patients with diabetes incorporated twice as much radioactivity as membrane proteins from normal erythrocytes. After acid hydrolysis, amino acid analysis showed that the majority of radioactivity was localized to glucosyllysine. Autoradiograms showed that all of the major proteins of the erythrocyte membrane, separated by electrophoresis on sodium dodecyl sulfate gels, contained ketoamine linkages. No protein bands in either normal or diabetic erythrocytes showed significant preferential ...