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

Welcome To The Journal Of Evolution And Health, Aaron Blaisdell, Paul Jaminet, David C. Pendergrass Oct 2013

Welcome To The Journal Of Evolution And Health, Aaron Blaisdell, Paul Jaminet, David C. Pendergrass

Aaron P Blaisdell

Welcome to the first issue of the Journal of Evolution and Health! The Journal of Evolution and Health is the peer-reviewed, open-access journal of the Ancestral Health Society, a community of scientists, healthcare professionals, and laypersons who collaborate to understand health challenges from an evolutionary perspective.


Cooperative Effects Of Drug-Resistance Mutations In The Flap Region Of Hiv-1 Protease, Jennifer Foulkes-Murzycki, Christina Rosi, Nese Yilmaz, Robert Shafer, Celia Schiffer Jul 2013

Cooperative Effects Of Drug-Resistance Mutations In The Flap Region Of Hiv-1 Protease, Jennifer Foulkes-Murzycki, Christina Rosi, Nese Yilmaz, Robert Shafer, Celia Schiffer

Celia A. Schiffer

Understanding the interdependence of multiple mutations in conferring drug resistance is crucial to the development of novel and robust inhibitors. As HIV-1 protease continues to adapt and evade inhibitors while still maintaining the ability to specifically recognize and efficiently cleave its substrates, the problem of drug resistance has become more complicated. Under the selective pressure of therapy, correlated mutations accumulate throughout the enzyme to compromise inhibitor binding, but characterizing their energetic interdependency is not straightforward. A particular drug resistant variant (L10I/G48V/I54V/V82A) displays extreme entropy-enthalpy compensation relative to wild-type enzyme but a similar variant (L10I/G48V/I54A/V82A) does not. Individual mutations of sites …


Translocation Channel Gating Kinetics Balances Protein Translocation Efficiency With Signal Sequence Recognition Fidelity, Steven Trueman, Elisabet Mandon, Reid Gilmore Jul 2013

Translocation Channel Gating Kinetics Balances Protein Translocation Efficiency With Signal Sequence Recognition Fidelity, Steven Trueman, Elisabet Mandon, Reid Gilmore

Elisabet Mandon

The transition between the closed and open conformations of the Sec61 complex permits nascent protein insertion into the translocation channel. A critical event in this structural transition is the opening of the lateral translocon gate that is formed by four transmembrane (TM) spans (TM2, TM3, TM7, and TM8 in Sec61p) to expose the signal sequence-binding site. To gain mechanistic insight into lateral gate opening, mutations were introduced into a lumenal loop (L7) that connects TM7 and TM8. The sec61 L7 mutants were found to have defects in both the posttranslational and cotranslational translocation pathways due to a kinetic delay in …


Structural And Thermodynamic Basis Of Amprenavir/Darunavir And Atazanavir Resistance In Hiv-1 Protease With Mutations At Residue 50, Seema Mittal, Rajintha Bandaranayake, Nancy King, Moses Prabu-Jeyabalan, Madhavi Nalam, Ellen Nalivaika, Nese Yilmaz, Celia Schiffer Jul 2013

Structural And Thermodynamic Basis Of Amprenavir/Darunavir And Atazanavir Resistance In Hiv-1 Protease With Mutations At Residue 50, Seema Mittal, Rajintha Bandaranayake, Nancy King, Moses Prabu-Jeyabalan, Madhavi Nalam, Ellen Nalivaika, Nese Yilmaz, Celia Schiffer

Celia A. Schiffer

Drug resistance occurs through a series of subtle changes that maintain substrate recognition but no longer permit inhibitor binding. In HIV-1 protease, mutations at I50 are associated with such subtle changes that confer differential resistance to specific inhibitors. Residue I50 is located at the protease flap tips, closing the active site upon ligand binding. Under selective drug pressure, I50V/L substitutions emerge in patients, compromising drug susceptibility and leading to treatment failure. The I50V substitution is often associated with amprenavir (APV) and darunavir (DRV) resistance, while the I50L substitution is observed in patients failing atazanavir (ATV) therapy. To explain how APV, …


Global Analysis Of Gene Expression Changes During Retinoic Acid-Induced Growth Arrest And Differentiation Of Melanoma: Comparison To Differentially Expressed Genes In Melanocytes Vs Melanoma, Mary H. Estler, Goran Boskovic, James Denvir, Sarah Miles, Donald A. Primerano, Richard M. Niles Jun 2013

Global Analysis Of Gene Expression Changes During Retinoic Acid-Induced Growth Arrest And Differentiation Of Melanoma: Comparison To Differentially Expressed Genes In Melanocytes Vs Melanoma, Mary H. Estler, Goran Boskovic, James Denvir, Sarah Miles, Donald A. Primerano, Richard M. Niles

Goran Boskovic

BACKGROUND: The incidence of malignant melanoma has significantly increased over the last decade. Some of these malignancies are susceptible to the growth inhibitory and pro-differentiating effects of all-trans-retinoic acid (RA). The molecular changes responsible for the biological activity of RA in melanoma are not well understood. RESULTS: In an analysis of sequential global gene expression changes during a 4-48 h RA treatment of B16 mouse melanoma cells, we found that RA increased the expression of 757 genes and decreased the expression of 737 genes. We also compared the gene expression profile (no RA treatment) between non-malignant melan-a mouse melanocytes and …


Human Monoclonal Antibody Mbl-Hcv1 Delays Hcv Viral Rebound Following Liver Transplantation: A Randomized Controlled Study, R. Chung, F. Gordon, M. Curry, T. Schiano, S. Emre, K. Corey, J. Markmann, M. Hertl, J. Pomposelli, E. Pomfret, S. Florman, M. Schilsky, Teresa Broering, Robert Finberg, Gyongyi Szabo, Phillip Zamore, U. Khettry, Gregory Babcock, Donna Ambrosino, Brett Leav, Mark Leney, H. Smith, Deborah Molrine May 2013

Human Monoclonal Antibody Mbl-Hcv1 Delays Hcv Viral Rebound Following Liver Transplantation: A Randomized Controlled Study, R. Chung, F. Gordon, M. Curry, T. Schiano, S. Emre, K. Corey, J. Markmann, M. Hertl, J. Pomposelli, E. Pomfret, S. Florman, M. Schilsky, Teresa Broering, Robert Finberg, Gyongyi Szabo, Phillip Zamore, U. Khettry, Gregory Babcock, Donna Ambrosino, Brett Leav, Mark Leney, H. Smith, Deborah Molrine

Gyongyi Szabo

Rapid allograft infection complicates liver transplantation (LT) in patients with hepatitis C virus (HCV). Pegylated interferon-alpha and ribavirin therapy after LT has significant toxicity and limited efficacy. The effect of a human monoclonal antibody targeting the HCV E2 glycoprotein (MBL-HCV1) on viral clearance was examined in a randomized, double-blind, placebo-controlled pilot study in patients infected with HCV genotype 1a undergoing LT. Subjects received 11 infusions of 50 mg/kg MBL-HCV1 (n=6) or placebo (n=5) intravenously with three infusions on day of transplant, a single infusion on days 1 through 7 and one infusion on day 14 after LT. MBL-HCV1 was well-tolerated …


Assessing Tissue Characterization Of Abdominal Organs Using Fuzzy C-Means Cluster Analysis Of Color- Fusion Mr Images, Terrance D. Weeden, H. Keith Brown Apr 2013

Assessing Tissue Characterization Of Abdominal Organs Using Fuzzy C-Means Cluster Analysis Of Color- Fusion Mr Images, Terrance D. Weeden, H. Keith Brown

Terrance Weeden

Color fusion MRI is being investigated for its value in automatic segmentation of tissues. An existing color fusion MRI data set of the liver, pancreas, and kidney of a normal male volunteer was analyzed both visually and statistically. Automatic tissue segmentation can allow better differentiation of abdominal pathologies, as well as pathologies associated with other organs. My research hypothesis is that fuzzy c-means clustering can be used to quantify the confidence levels of the correct classification of renal, pancreatic, and hepatic tissues visualized by the color fusion MRI method. Results from data show that fuzzy c-means clustering can be used …


Tca Cycle Inactivation In Staphylococcus Aureus Alters Nitric Oxide Production In Raw 264.7 Cells, Chandirasegaran Massilamany, Arunakumar Gangaplara, Donald Gardner, James Musser, David Steffen, Greg Somerville, Jay Reddy Apr 2013

Tca Cycle Inactivation In Staphylococcus Aureus Alters Nitric Oxide Production In Raw 264.7 Cells, Chandirasegaran Massilamany, Arunakumar Gangaplara, Donald Gardner, James Musser, David Steffen, Greg Somerville, Jay Reddy

Greg A. Somerville

Inactivation of the Staphylococcus aureus tricarboxylic acid (TCA) cycle delays the resolution of cutaneous ulcers in a mouse soft tissue infection model. In this study, it was observed that cutaneous lesions in mice infected with wild-type or isogenic aconitase mutant S. aureus strains contained comparable inflammatory infiltrates, suggesting the delayed resolution was independent of the recruitment of immune cells. These observations led us to hypothesize that staphylococcal metabolism can modulate the host immune response. Using an in vitro model system involving RAW 264.7 cells, the authors observed that cells cultured with S. aureus aconitase mutant strains produced significantly lower amounts …


Inhibition Of Bacillus Cereus Growth By Bacteriocin Producing Bacillus Subtilis Isolated From Fermented Baobab Seeds (Maari) Is Substrate Dependent, Donatien Kaboré, Dennis S. Nielsen, Hagrétoui Sawadogo-Lingan, Bréhima Diawara, Mamoudou H. Dicko Prof., Mogens Jakobsen, Line Thorsen Jan 2013

Inhibition Of Bacillus Cereus Growth By Bacteriocin Producing Bacillus Subtilis Isolated From Fermented Baobab Seeds (Maari) Is Substrate Dependent, Donatien Kaboré, Dennis S. Nielsen, Hagrétoui Sawadogo-Lingan, Bréhima Diawara, Mamoudou H. Dicko Prof., Mogens Jakobsen, Line Thorsen

Pr. Mamoudou H. DICKO, PhD

Maari is a spontaneously alkaline fermented food condiment made from baobab tree seeds. Due to the spontaneous nature of maari fermentations growth of the opportunistic human pathogen Bacillus cereus is occasionally observed. Bacillus subtilis strains are important for alkaline seed fermentations because of their enzymatic activities contributing to desirable texture, flavor and pH development. Some B. subtilis strains have antimicrobial properties against B. cereus. In the present work, three bacteriocin producing B. subtilis strains (B3, B122 and B222) isolated from maari were tested. The production of antimicrobial activity by the three strains was found to be greatly influenced by the …


Structure And Dynamics Of A Primordial Catalytic Fold Generated By In Vitro Evolution, Fa-An Chao, Aleardo Morelli, John C. Haugner Iii, Lewis Churchfield, Lei Shi, Larry R. Masterson, Ritimukta Sarangi, Gianluigi Veglia, Burckhard Seelig Dec 2012

Structure And Dynamics Of A Primordial Catalytic Fold Generated By In Vitro Evolution, Fa-An Chao, Aleardo Morelli, John C. Haugner Iii, Lewis Churchfield, Lei Shi, Larry R. Masterson, Ritimukta Sarangi, Gianluigi Veglia, Burckhard Seelig

Larry Masterson

Engineering functional protein scaffolds capable of carrying out chemical catalysis is a major challenge in enzyme design. Starting from a noncatalytic protein scaffold, we recently generated a new RNA ligase by in vitro directed evolution. This artificial enzyme lost its original fold and adopted an entirely new structure with substantially enhanced conformational dynamics, demonstrating that a primordial fold with suitable flexibility is sufficient to carry out enzymatic function.