Structure-substrate Binding Relationships of HIV-1 Reverse Transcriptase
Author: Steve Chien-Wen Huang
Publisher:
Published: 1994
Total Pages: 184
ISBN-13:
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Author: Steve Chien-Wen Huang
Publisher:
Published: 1994
Total Pages: 184
ISBN-13:
DOWNLOAD EBOOKAuthor: Ke Li
Publisher:
Published: 1996
Total Pages: 452
ISBN-13:
DOWNLOAD EBOOKAuthor: Matthew William Kellinger
Publisher:
Published: 2010
Total Pages: 390
ISBN-13:
DOWNLOAD EBOOKWe have engineered a mutant of HIV Reverse Transcriptase that can be fluorescently labeled by covalent attachment of the environmentally sensitive fluorophore 7-diethylamino-3-((((2-maleimidyl)ethyl)amino)carbonyl)coumarin (MDCC). The result is a polymerase that is kinetically indistinguishable from the wild-type enzyme, but provides a signal to monitor changes in enzyme structure that result from conformational changes induced by substrate binding. Using this system, we have expanded the kinetic model governing nucleotide binding to include an enzymatic isomerization following initial nucleotide binding. In doing so, we define the role of induced-fit in nucleotide specificity and mismatch discrimination. Additionally, we have characterized the kinetics governing the specificity and discrimination of several widely administered Nucleotide Reverse Transcriptase Inhibitors (NRTI's) used to combat HIV infection including 3TC (Lamivudine), FTC (Emtricitabine), and AZT (Zidovudine) for the wild-type polymerase and mutants with clinical resistance to these compounds. Our findings resolve the apparent tighter binding of these inhibitor compounds compared to the correct nucleotide by showing that the affinity for the correct nucleotide is stronger than the inhibitors. The apparent weaker binding of the correct nucleotide is a result of a incomplete interpretation of binding data that fails to account for the importance of the reverse rate of the conformational change. The apparent Kd (Kd, app) measurements for correct nucleotide estimates Km rather than Kd because nucleotide binding does not reach equilibrium. The conformationally sensitive enzyme has also been used to characterize the kinetics governing DNA association. We show that DNA binding is governed by a two-step process where a fast initial association is followed by a second, slow isomerization that is off the pathway for nucleotide binding and incorporation. Finally, we have implemented single molecule techniques using fluorophore labeled nucleotides to study the effects of AZT incorporation on the DNA translocation dynamics of the polymerase. We find that primer termination with AZT results in DNA that fails to translocate, therefore occluding the next nucleotide from binding. This shift in translocation equilibrium exposes the newly formed phosphodiester bond to ATP- or pyrophosphate-mediated AZT excision; thereby rescuing productive polymerization. This finding represents the first kinetic measurement of DNA translocation by a polymerase.
Author: Nouri Neamati
Publisher: John Wiley & Sons
Published: 2011-08-10
Total Pages: 710
ISBN-13: 1118015363
DOWNLOAD EBOOKThis book comprehensively covers the mechanisms of action and inhibitor design for HIV-1 integrase. It serves as a resource for scientists facing challenging drug design issues and researchers in antiviral drug discovery. Despite numerous review articles and isolated book chapters dealing with HIV-1 integrase, there has not been a single source for those working to devise anti-AIDS drugs against this promising target. But this book fills that gap and offers a valuable introduction to the field for the interdisciplinary scientists who will need to work together to design drugs that target HIV-1 integrase.
Author: Katsuhiko S. Murakami
Publisher: Springer Science & Business Media
Published: 2013-10-22
Total Pages: 342
ISBN-13: 3642397964
DOWNLOAD EBOOKThis book provides a review of the multitude of nucleic acid polymerases, including DNA and RNA polymerases from Archea, Bacteria and Eukaryota, mitochondrial and viral polymerases, and other specialized polymerases such as telomerase, template-independent terminal nucleotidyl transferase and RNA self-replication ribozyme. Although many books cover several different types of polymerases, no book so far has attempted to catalog all nucleic acid polymerases. The goal of this book is to be the top reference work for postgraduate students, postdocs, and principle investigators who study polymerases of all varieties. In other words, this book is for polymerase fans by polymerase fans. Nucleic acid polymerases play a fundamental role in genome replication, maintenance, gene expression and regulation. Throughout evolution these enzymes have been pivotal in transforming life towards RNA self-replicating systems as well as into more stable DNA genomes. These enzymes are generally extremely efficient and accurate in RNA transcription and DNA replication and share common kinetic and structural features. How catalysis can be so amazingly fast without loss of specificity is a question that has intrigued researchers for over 60 years. Certain specialized polymerases that play a critical role in cellular metabolism are used for diverse biotechnological applications and are therefore an essential tool for research.
Author: Sharon Michele Walker
Publisher:
Published: 1995
Total Pages: 360
ISBN-13:
DOWNLOAD EBOOKAuthor: Robert J.. Crouch
Publisher:
Published: 1998-01-01
Total Pages: 265
ISBN-13: 9782855985978
DOWNLOAD EBOOKAuthor: Gabriele Cruciani
Publisher: John Wiley & Sons
Published: 2006-05-12
Total Pages: 328
ISBN-13: 3527607137
DOWNLOAD EBOOKThis unique reference source, edited by the world's most respected expert on molecular interaction field software, covers all relevant principles of the GRID force field and its applications in medicinal chemistry. Entire chapters on 3D-QSAR, pharmacophore searches, docking studies, metabolism predictions and protein selectivity studies, among others, offer a concise overview of this emerging field. As an added bonus, this handbook includes a CD-ROM with the latest commercial versions of the GRID program and related software.
Author: Andreas Holzenburg
Publisher: Springer Science & Business Media
Published: 2007-05-08
Total Pages: 528
ISBN-13: 0306476509
DOWNLOAD EBOOKStructure-Function Relationships of Human Pathogenic Viruses provides information on the mechanisms by which viruses enter the cell, replicate, package their DNA into capsids and mature into new virions. The relation between structural features and the pathogenicity and oncogenicity of some of the most relevant human viral pathogens are demonstrated and the acquisition of defense mechanisms through virus-host interactions are presented. In contrast to textbooks, this volume combines timely research data to provide a holistic view of viral pathogenesis. Furthermore Structure-Function Relationships of Human Pathogenic Viruses illustrates in a single volume the fundamental processes involved in viral life cycles using up-to-date information from research laboratories around the world. Knowledge of these processes is crucial to develop rationales for the design of future drugs. The timeliness of the data and the comprehensive yet concise approach this book takes in order to present the world of viral pathogens should make it a frontrunner in higher education and R&D.
Author: Jean-Paul Renaud
Publisher: John Wiley & Sons
Published: 2020-01-09
Total Pages: 1367
ISBN-13: 1118900502
DOWNLOAD EBOOKWith the most comprehensive and up-to-date overview of structure-based drug discovery covering both experimental and computational approaches, Structural Biology in Drug Discovery: Methods, Techniques, and Practices describes principles, methods, applications, and emerging paradigms of structural biology as a tool for more efficient drug development. Coverage includes successful examples, academic and industry insights, novel concepts, and advances in a rapidly evolving field. The combined chapters, by authors writing from the frontlines of structural biology and drug discovery, give readers a valuable reference and resource that: Presents the benefits, limitations, and potentiality of major techniques in the field such as X-ray crystallography, NMR, neutron crystallography, cryo-EM, mass spectrometry and other biophysical techniques, and computational structural biology Includes detailed chapters on druggability, allostery, complementary use of thermodynamic and kinetic information, and powerful approaches such as structural chemogenomics and fragment-based drug design Emphasizes the need for the in-depth biophysical characterization of protein targets as well as of therapeutic proteins, and for a thorough quality assessment of experimental structures Illustrates advances in the field of established therapeutic targets like kinases, serine proteinases, GPCRs, and epigenetic proteins, and of more challenging ones like protein-protein interactions and intrinsically disordered proteins