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Amino Acids, Peptides, and Proteins

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Articles 61 - 69 of 69

Full-Text Articles in Pharmaceutics and Drug Design

Cysteine And Arginine-Rich Peptides As Molecular Carriers, Amir Nasrolahi Shirazi, Naglaa Salem El-Sayed, Dindayal Mandal, Rakesh Tiwari, Kathy Tavakoli, Matthew Eteshem, Keykavous Parang Nov 2015

Cysteine And Arginine-Rich Peptides As Molecular Carriers, Amir Nasrolahi Shirazi, Naglaa Salem El-Sayed, Dindayal Mandal, Rakesh Tiwari, Kathy Tavakoli, Matthew Eteshem, Keykavous Parang

Pharmacy Faculty Articles and Research

A number of linear and cyclic peptides containing alternative arginine and cysteine residues, namely linear (CR)3, linear (CR)4, linear (CR)5, cyclic [CR]4, and cyclic [CR]5, were synthesized. The peptides were evaluated for their ability to deliver two molecular cargos, fluorescence-labeled cell-impermeable negatively charged phosphopeptide (F′-GpYEEI) and fluorescence-labeled lamivudine (F′-3TC), intracellularly in human leukemia cancer (CCRF-CEM) cells. We investigated the role of cyclization and the number of amino acids in improving the transporting ability of the peptides. The flow cytometry studies suggested that the synthesized peptides were able to work efficiently as …


Molecular Overlap In The Regulation Of Sk Channels By Small Molecules And Phosphoinositides, Miao Zhang, Xuan-Yu Meng, Ji-Fang Zhang, Meng Cui, Diomedes E. Logothetis Jul 2015

Molecular Overlap In The Regulation Of Sk Channels By Small Molecules And Phosphoinositides, Miao Zhang, Xuan-Yu Meng, Ji-Fang Zhang, Meng Cui, Diomedes E. Logothetis

Pharmacy Faculty Articles and Research

Phosphatidylinositol 4,5-bisphosphate (PIP2) directly interacts with the small-conductance Ca2+-activated K+ 2-a (SK2-a) channel/calmodulin complex, serving as a critical element in the regulation of channel activity. We report that changes of protein conformation in close proximity to the PIP2 binding site induced by a small-molecule SK channel modulator, NS309, can effectively enhance the interaction between the protein and PIP2 to potentiate channel activity. This novel modulation of PIP2 sensitivity by small-molecule drugs is likely not to be limited in its application to SK channels, representing an intriguing strategy to develop drugs controlling the activity of the large number of PIP2-dependent proteins.


Cationic Cell-Penetrating Peptides Are Potent Furin Inhibitors, Bruno Ramos-Molina, Adam N. Lick, Amir Nasrolahi Shirazi, Donghoon Oh, Rakesh Tiwari, Naglaa Salem El-Sayed, Keykavous Parang, Iris Lindberg Jun 2015

Cationic Cell-Penetrating Peptides Are Potent Furin Inhibitors, Bruno Ramos-Molina, Adam N. Lick, Amir Nasrolahi Shirazi, Donghoon Oh, Rakesh Tiwari, Naglaa Salem El-Sayed, Keykavous Parang, Iris Lindberg

Pharmacy Faculty Articles and Research

Cationic cell-penetrating peptides have been widely used to enhance the intracellular delivery of various types of cargoes, such as drugs and proteins. These reagents are chemically similar to the multi-basic peptides that are known to be potent proprotein convertase inhibitors. Here, we report that both HIV-1 TAT47-57 peptide and the Chariot reagent are micromolar inhibitors of furin activity in vitro. In agreement, HIV-1 TAT47-57 reduced HT1080 cell migration, thought to be mediated by proprotein convertases, by 25%. In addition, cyclic polyarginine peptides containing hydrophobic moieties which have been previously used as transfection reagents also exhibited potent furin inhibition in vitro …


Novel Therapy For Nicotine Addiction In Alcohol Dependent Rats, Bethany Ann Stennett Jan 2013

Novel Therapy For Nicotine Addiction In Alcohol Dependent Rats, Bethany Ann Stennett

UNF Graduate Theses and Dissertations

The co-dependence of nicotine and alcohol addiction occurs at high rates, complicates treatment, and is often associated with significant morbidity and mortality. Treatment options of alcohol and tobacco co-dependence are limited. Currently, there are drugs available for nicotine dependence or alcohol dependence. However, there are no therapeutic drugs available on the market for the co-dependence of nicotine and alcohol. Therefore, and important opportunity of new therapeutic options and drug development has presented itself. NT69L, a non-selective neurotensin (NT) agonist, provides a potential novel therapy for nicotine addiction in alcoholics by interacting with the common neurotransmitter circuits supporting the rewarding process …


N-Myristoylglutamic Acid Derivative Of 3′-Fluoro-3′- Deoxythymidine As An Organogel, Bhupender S. Chhikara, Rakesh Tiwari, Keykavous Parang Jan 2012

N-Myristoylglutamic Acid Derivative Of 3′-Fluoro-3′- Deoxythymidine As An Organogel, Bhupender S. Chhikara, Rakesh Tiwari, Keykavous Parang

Pharmacy Faculty Articles and Research

Designing microbicidal gels of anti-HIV drugs for local application to prevent HIV infection is a subject of major interest. 3′-Fluoro-3′-deoxythymidine (FLT), a nucleoside reverse transcriptase inhibitor (NRTI), was conjugated with a N-myristoylglutamate scaffold. The conjugate showed gelation at 1% (w/w) in different organic solvents, such as toluene, dichloromethane, and chloroform. The gels were opaque and stable at room temperature. The results indicate that myristoyl glutamate derivative of FLT can form an organogel. The gel could have potential application as a topical anti-HIV microbicidal agent.


Hepatic Immunosuppressive Effects Of Systemically- Administered Novel Dextran-Methylprednisolone Prodrugs With Peptide Linkers In Rats, Imam H. Shaik, Hitesh K. Agarwal, Keykavous Parang, Reza Mehvar Jan 2012

Hepatic Immunosuppressive Effects Of Systemically- Administered Novel Dextran-Methylprednisolone Prodrugs With Peptide Linkers In Rats, Imam H. Shaik, Hitesh K. Agarwal, Keykavous Parang, Reza Mehvar

Pharmacy Faculty Articles and Research

The hepatic immunosuppressive activities of two novel dextran prodrugs of methylprednisolone (MP) containing one (DMP1) or five (DMP5) amino acids as linkers were studied in rats. At various times (02 weeks) after intravenous administration of single 5 mg/kg (MP equivalent) doses of each prodrug or MP succinate (MPS), livers were isolated and immunologically stimulated ex vivo with lipopolysaccharide. The concentrations of tumor necrosis factor (TNF)-a in the outlet perfusate were then quantitated to assess immune response. Additionally, the concentrations of DMP1, DMP5, and/or MP were measured in the liver. MPS, DMP5, or DMP1 injections caused a maximum of 48.9%, 63.5%, …


Simulating Molecular Mechanisms Of The Mdm2-Mediated Regulatory Interactions: A Conformational Selection Model Of The Mdm2 Lid Dynamics, Gennady M. Verkhivker Jan 2012

Simulating Molecular Mechanisms Of The Mdm2-Mediated Regulatory Interactions: A Conformational Selection Model Of The Mdm2 Lid Dynamics, Gennady M. Verkhivker

Mathematics, Physics, and Computer Science Faculty Articles and Research

Diversity and complexity of MDM2 mechanisms govern its principal function as the cellular antagonist of the p53 tumor suppressor. Structural and biophysical studies have demonstrated that MDM2 binding could be regulated by the dynamics of a pseudo-substrate lid motif. However, these experiments and subsequent computational studies have produced conflicting mechanistic models of MDM2 function and dynamics. We propose a unifying conformational selection model that can reconcile experimental findings and reveal a fundamental role of the lid as a dynamic regulator of MDM2-mediated binding. In this work, structure, dynamics and energetics of apo-MDM2 are studied as a function of posttranslational modifications …


Pk/Pd Modelling Of Comb-Shaped Pegylated Salmon Calcitonin Conjugates Of Differing Molecular Weights, Sinead Ryan, Jesus Maria Frias, David H. Haddleton, David J. Brayden Jan 2010

Pk/Pd Modelling Of Comb-Shaped Pegylated Salmon Calcitonin Conjugates Of Differing Molecular Weights, Sinead Ryan, Jesus Maria Frias, David H. Haddleton, David J. Brayden

Articles

Salmon calcitonin (sCT) was conjugated via cysteine-1 to novel combed-shaped end-functionalised poly(PEG) methyl ether methacrylate) (sCT-P) comb-shaped polymers, to yield conjugates of total molecular weights (MW) inclusive of sCT: 6.5, 9.5, 23 and 40 kDa. The conjugates were characterised by HPLC and their in vitro and in vivo bioactivity was measured by cAMP assay on human T47D cells and following intravenous (i.v.) injection to rats, respectively. Stability against endopeptidases, rat serum and liver homogenates was assessed. There were linear and exponential relationships between conjugate MW with potency and efficacy respectively, however the largest MW conjugate still retained 70% of E …


The Role Of Multi-Drug Resistance Associated Protein 4 And P-Glycoprotein In Resistance Of Neuroblastoma To Topotecan And Irinotecan, Patricia Kellie Turner Dec 2007

The Role Of Multi-Drug Resistance Associated Protein 4 And P-Glycoprotein In Resistance Of Neuroblastoma To Topotecan And Irinotecan, Patricia Kellie Turner

Theses and Dissertations (ETD)

High-risk neuroblastoma presents a significant therapeutic challenge because the 5-year survival rate remains less than 30% despite the use of surgery, multi-agent chemotherapy, radiation, and autologous bone marrow transplant. Novel therapeutic modalities are under development. The camptothecin analogs topotecan and irinotecan have been identified as successful cytotoxic agents. For topotecan, pharmacokinetically guided dosing to achieve a systemic exposure associated with preclinical anti-tumor activity in neuroblastoma xenograft models is feasible and has elicited favorable responses in children with high-risk neuroblastoma. However, some children with high-risk disease did not respond to the putatively effective topotecan systemic exposure. These children represent a subset …