Life Sciences Commons^™

A Simple Spectrophotometric Streptavidin-Biotin Binding Assay Utilizing Biotin-4-Fluorescein., Mark Waner, David Mascotti

Mark J. Waner

A new assay for biotin binding capacity of Streptavidin (SA) is presented in this work. The assay is based on the large decrease in the extinction coefficient at 493 nm that accompanies binding of biotin-4-fluorescein (B4F) to SA. This decrease is attributed to formation of a charge transfer complex between the B4F-donor and one or more SA residues. We show that one may observe the stoichiometric binding via monitoring the absorbance at 493 nm using either SA or B4F as the titrant. The sensitivity of the assay is at the lower end of similar fluorimetric and photometric assays. Though the …

Laser-Induced Photon-Branched Chain Reaction In A Chemically-Active Gas-Dispersed Medium, Thomas F. George, Renat R. Letfullin, Galen C. Duree

Thomas George

Web-Based Arabidopsis Functional And Structural Genomics Resources, Yan Lu, Robert Last

Yan Lu

No abstract provided.

A Simple Spectrophotometric Streptavidin-Biotin Binding Assay Utilizing Biotin-4-Fluorescein., Mark Waner, David Mascotti

David P. Mascotti

A new assay for biotin binding capacity of Streptavidin (SA) is presented in this work. The assay is based on the large decrease in the extinction coefficient at 493 nm that accompanies binding of biotin-4-fluorescein (B4F) to SA. This decrease is attributed to formation of a charge transfer complex between the B4F-donor and one or more SA residues. We show that one may observe the stoichiometric binding via monitoring the absorbance at 493 nm using either SA or B4F as the titrant. The sensitivity of the assay is at the lower end of similar fluorimetric and photometric assays. Though the …

Psf2 Plays Important Roles In Normal Eye Development In Xenopus Laevis, Brian Walter, Kimberly Perry, Lisa Fukui, Erica Malloch, Jason Weaver, Jonathan Henry

Brian Walter

No abstract provided.

Writing Research Proposal: Literature Review And Database Search, Mamoudou H. Dicko Prof.

Pr. Mamoudou H. DICKO, PhD

Dioxidobis(2-Oxo-1,2-Dihydropyridin-3-Olato)­Molybdenum(Vi), Manoj Trivedi, Daya Shankar Pandey, Nigam P. Rath

Nigam Rath

Diethyl 2-[(4-Nitro­Phen­Yl)(4-Phenyl-1,2,3-Selenadiazol-5-Yl)Meth­Yl]Malonate, A. Marx, S. Saravanan, S. Muthusubramanian, V. Manivannan, Nigam P. Rath

Nigam Rath

New Connections Across Pathways And Cellular Processes: Industrialized Mutant Screening Reveals Novel Associations Between Diverse Phenotypes In Arabidopsis, Yan Lu, Linda Savage, Imad Ajjawi, Kathreen Imre, David Yoder, Christoph Benning, Dean Dellapenna, John Ohlrogge, Katherine Osteryoung, Andreas Weber, Curtis Wilkerson, Robert Last

Yan Lu

No abstract provided.

Second-Sphere Amino Acids Contribute To Transition-State Structure In Bovine Purine Nucleoside Phosphorylase, Lei Li, Minkui Luo, Mahmoud Ghanem, Erika A. Taylor, Vern L. Schramm

Erika A. Taylor, Ph.D.

Transition-state structures of human and bovine of purine nucleoside phosphorylases differ, despite 87% homologous amino acid sequences. Human PNP (HsPNP) has a fully dissociated transition state, while that for bovine PNP (BtPNP) has early SN1 character. Crystal structures and sequence alignment indicate that the active sites of these enzymes are the same within crystallographic analysis, but residues in the second-sphere from the active sites differ significantly. Residues in BtPNP have been mutated toward HsPNP, resulting in double (Asn123Lys; Arg210Gln) and triple mutant PNPs (Val39Thr; Asn123Lys; Arg210Gln). Steady-state kinetic studies indicated unchanged catalytic activity, while pre-steady-state studies indicate that the chemical …

4-(4-Chlorophenyl)-5-[1-(4-Chlorophenyl)-2-Methyl-2-Nitropropyl]-1,2,3-Selenadiazole, A. Marx, S. Saravanan, S. Muthusubramanian, V. Manivannan, Nigam P. Rath

Nigam Rath

'Partial Derivatives: Are You Kidding?': Teaching Thermodynamics Using Virtual Substance, Chrystal Bruce, Carribeth Bliem, John Papanikolas

Chrystal D. Bruce

No abstract provided.

Invited Review: Heat Shock Proteins And Exercise: A Primer, Earl Noble, Kevin Milne, C.W. Melling

Jamie Melling

Heat shock proteins (HSPs) are, in general, prosurvival molecules within the cellular environment, and the overexpression of even just 1 family of HSPs can lead to protection against and improvements after a variety of stressors. Not surprisingly, a fertile area of study has grown out of effors to exploit the innate biologic behaviour of HSPs. Exercise, because of the inherent physiologic stresses associated with it, is but 1 stimulus that can result in a robust increase in various HSPs in several tissues, not the least of which happen to be the heart and skeletal muscle. The purpose of this review …

Combating Drug Resistance – Identifying Resilient Molecular Targets And Robust Drugs, Celia Schiffer

Celia A. Schiffer

In: Robert M. Stroud and Janet Finer-Moore, Computational and Structural Approaches to Drug Discovery: Ligand-Protein Interactions, Royal Society of Chemistry, 2008, Chapter 7, p. 127-132. ISBN 0854043659, 9780854043651.

Heat Shock Proteins And Whole Body Physiology, Earl Nobe, C.W. James Melling, Kevin Milne

Jamie Melling

No abstract provided.

Mechanism Of Cu+-Transporting Atpases: Soluble Cu+ Chaperones Directly Transfer Cu+ To Transmembrane Transport Sites, José Argüello, Manuel Gonzalez-Guerrero

José M. Argüello

As in other P-type ATPases, metal binding to transmembrane metal-binding sites (TM-MBS) in Cu(+)-ATPases is required for enzyme phosphorylation and subsequent transport. However, Cu(+) does not access Cu(+)-ATPases in a free (hydrated) form but is bound to a chaperone protein. Cu(+) transfer from Cu(+) chaperones to regulatory cytoplasmic metal-binding domains (MBDs) present in these ATPases has been described, but there is no evidence of a proposed subsequent Cu(+) movement from the MBDs to the TM-MBS. Alternatively, we postulate the parsimonious Cu(+) transfer by the chaperone directly to TM-MBS. Testing both models, the delivery of Cu(+) by Archaeoglobus fulgidus Cu(+) chaperone …

Imaging Of Transplanted Pancreatic Islets In Vivo, P. Joo Ho Tai, C. Foster, C. Hasil, C.W.J. Melling, D. White

Jamie Melling

No abstract provided.

Mutual Information Without The Influence Of Phylogeny Or Entropy Dramatically Improves Residue Contact Prediction, Stanley Dunn, Lindi Wahl, Gregory Gloor

Stanley D Dunn

Motivation: Compensating alterations during the evolution of protein families give rise to coevolving positions that contain important structural and functional information. However, a high background composed of random noise and phylogenetic components interferes with the identification of coevolving positions.

Results: We have developed a rapid, simple and general method based on information theory that accurately estimates the level of background mutual information for each pair of positions in a given protein family. Removal of this background results in a metric, MIp, that correctly identifies substantially more coevolving positions in protein families than any existing method. A significant fraction of these …

Flexible Filamentous Virus Structures From Fiber Diffraction, Gerald Stubbs, Amy Kendall, Michele Mcdonald, Wen Bian, Timothy Bowles, Sarah Baumgarten, Ian Mccullough, Jian Shi, Phoebe Stewart, Esther Bullitt, David Gore, Said Ghabrial

Ian McCullough

Fiber diffraction data have been obtained from Narcissus mosaic virus, a potexvirus from the family Flexiviridae, and soybean mosaic virus (SMV), a potyvirus from the family Potyviridae. Analysis of the data in conjunction with cryo-electron microscopy data allowed us to determine the symmetry of the viruses and to make reconstructions of SMV at 19 Å resolution and of another potexvirus, papaya mosaic virus, at 18 Å resolution. These data include the first well-ordered data ever obtained for the potyviruses and the best-ordered data from the potexviruses, and offer the promise of eventual high resolution structure determinations.

Structural And Dynamic Basis Of Phospholamban And Sarcolipin Inhibition Of Ca2+-Atpase, Nathaniel J. Traaseth, Kim N. Ha, Raffaello Verardi, Lei Shi, Jarrod J. Buffy, Larry R. Masterson, Gianluigi Veglia

Larry Masterson

Hierarchies Of Networked Phases Induced By Multiple Liquid-Liquid Critical Points, C. W. Hsu, J. Largo, F. W. Sciortino, Francis Starr

Francis Starr

No abstract provided.

Tetra-N-Butyl­Ammonium Bis­(2,2-Dicyano­Ethyl­Ene-1,1-Dithiol­Ato)Palladium(Ii), Nyasha Kanganga, Kent R. Mann, Daron E. Janzen

Daron E Janzen, Ph.D.

No abstract provided.

Tetra-N-Butyl-Ammonium Bis-(1,1-Dicyano-Ethyl-Ene-2,2-Dithiol-Ato)Platinum(Ii), Nyasha Kanganga, Kent R. Mann, Daron E. Janzen

Daron E Janzen, Ph.D.

No abstract provided.