Biochemistry, Biophysics, and Structural Biology Commons^™

Modulation Of Escherichia Coli Translation By The Specific Inactivation Of TrnaGly Under Oxidative Stress, Lorenzo Eugenio Leiva, Andrea Pincheira, Sara Elgamal, Sandra D. Kienast, Verónica Bravo, Johannes Leufken, Daniela Gutiérrez, Sebastian A. Leidel, Michael Ibba, Assaf Katz

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Bacterial oxidative stress responses are generally controlled by transcription factors that modulate the synthesis of RNAs with the aid of some sRNAs that control the stability, and in some cases the translation, of specific mRNAs. Here, we report that oxidative stress additionally leads to inactivation of tRNA^Gly in Escherichia coli, inducing a series of physiological changes. The observed inactivation of tRNA^Gly correlated with altered efficiency of translation of Gly codons, suggesting a possible mechanism of translational control of gene expression under oxidative stress. Changes in translation also depended on the availability of glycine, revealing a mechanism whereby bacteria …

Translational Regulation Of Environmental Adaptation In Bacteria, Rodney Tollerson Ii, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Bacteria must rapidly respond to both intracellular and environmental changes to survive. One critical mechanism to rapidly detect and adapt to changes in environmental conditions is control of gene expression at the level of protein synthesis. At each of the three major steps of translation—initiation, elongation, and termination—cells use stimuli to tune translation rate and cellular protein concentrations. For example, changes in nutrient concentrations in the cell can lead to translational responses involving mechanisms such as dynamic folding of riboswitches during translation initiation or the synthesis of alarmones, which drastically alter cell physiology. Moreover, the cell can fine-tune the levels …

Selective Autophagy Maintains The Aryl Hydrocarbon Receptor Levels In Hela Cells: A Mechanism That Is Dependent On The P23 Co-Chaperone, Yujie Yang, William K. Chan

School of Pharmacy Faculty Articles

The aryl hydrocarbon receptor (AHR) is an environmental sensing molecule which impacts diverse cellular functions such as immune responses, cell growth, respiratory function, and hematopoietic stem cell differentiation. It is widely accepted that the degradation of AHR by 26S proteasome occurs after ligand activation. Recently, we discovered that HeLa cells can modulate the AHR levels via protein degradation without exogenous treatment of a ligand, and this degradation is particularly apparent when the p23 content is down-regulated. Inhibition of autophagy by a chemical agent (such as chloroquine, bafilomycin A1, or 3-methyladenine) increases the AHR protein levels in HeLa cells whereas activation …

Effects Of Nicotinamide Riboside And Beta-Hydroxybutyrate On C. Elegans Lifespan, Jeffery Peters

Undergraduate Honors Theses

The nicotinamide riboside (NR) form of vitamin B₃and the ketone body ß-hydroxybutyrate (BHB) are two of the most promising natural compounds yet identified for the treatment of aging and aging-related diseases. Forms of vitamin B₃are precursors for the synthesis of the coenzymes nicotinamide adenine dinucleotide (NAD(H)) and nicotinamide adenine dinucleotide phosphate (NADP(H)). In aged cells levels of NAD⁺decline, decreasing metabolism and decreasing activity of protective sirtuin protein deacetylases. In aged cells NR, but not more common forms of vitamin B3, boost NAD⁺levels. BHB is naturally produced by the body when individuals fast …

A Study Of The Antioxidant Versus Pro-Oxidant Nature Of The Amyloid Beta Peptide And An Analysis Of The Natural Products, Isorhamnetin And Narignenin, As Antioxidants, Kaylee Holmes

Honors Theses

Alzheimer’s disease is a neurodegenerative disorder with no cure. Due to the widespread effects of this disease, abundant research efforts have gone towards finding a cure. The amyloid beta (Ab) peptide has been shown to be a potential cause of the disease due to destructive effects on tissues that it can have both by itself and through reactive oxygen species (ROS) generation. This study was performed in order to assess the structural properties of Ab₄₂monomers, fibrils and oligomers, to assess the antioxidant versus pro-oxidant behavior of the Ab peptide, and to assess the antioxidant nature of the natural …

Aminoacyl-Trna Synthetases, Miguel Angel Rubio Gomez, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The aminoacyl-tRNA synthetases are an essential and universally distributed family of enzymes that plays a critical role in protein synthesis, pairing tRNAs with their cognate amino acids for decoding mRNAs according to the genetic code. Synthetases help to ensure accurate translation of the genetic code by using both highly accurate cognate substrate recognition and stringent proofreading of noncognate products. While alterations in the quality control mechanisms of synthetases are generally detrimental to cellular viability, recent studies suggest that in some instances such changes facilitate adaption to stress conditions. Beyond their central role in translation, synthetases are also emerging as key …

Network Approaches To Elucidate The Determinants Of Protein Topology And Stability, Zeinab Haratipour

Chemistry & Biochemistry Theses & Dissertations

Predicting three-dimensional structures of proteins from sequence information alone, remains one of the most profoundly challenging and intensely studied problems in basic science. It has uniquely garnered the interdisciplinary efforts of biologists, biochemists, computer scientists, mathematicians and physicists. The advancement of computational methods to study fundamental features of proteins also enables insights that are either difficult to explore experimentally or complimentary to further interpret experimental data. In the present research and through the combined development and application of molecular dynamics and network science approaches we aimed to elucidate the role of geographically important amino acids and evolutionarily conserved long-range interactions …

Evaluating The Anti-Cancer Efficacy Of A Synthetic Curcumin Analog On Human Melanoma Cells And Its Interaction With Standard Chemotherapeutics, Krishan Parashar, Siddhartha Sood, Ali Mehaidli, Colin Curran, Caleb Vegh, Christopher Nguyen, Christopher Pignanelli, Jianzhang Wu, Guang Liang, Yi Wang, Siyaram Pandey

Medical Student Research Symposium

Melanoma is the leading cause of skin-cancer related deaths in North America. Metastatic melanoma is difficult to treat and chemotherapies have limited success. Furthermore, chemotherapies lead to toxic side effects due to nonselective targeting of normal cells. Curcumin is a natural product of Curcuma longa (turmeric) and has been shown to possess anti-cancer activity. However, due to its poor bioavailability and stability, natural curcumin is not an effective cancer treatment. We tested synthetic analogs of curcumin that are more stable. One of these derivatives, Compound A, has shown significant anti-cancer efficacy in colon, leukemia, and triple-negative inflammatory breast cancer cells. …

Bone Marrow Concentrate (Bmc) Therapy In Musculoskeletal Disorders: Evidence-Based Policy Position Statement Of American Society Of Interventional Pain Physicians (Asipp), Laxmaiah Manchikanti, Christopher J. Centeno, Sairam Atluri, Sheri L. Albers, Shane Shapiro, Gerard A. Malanga, Alaa Abd-Elsayed, Mairin Jerome, Joshua A. Hirsch, Alan David Kaye, Steve M. Aydin, Douglas Beall, Don Buford, Joanne Borg-Stein, Ricardo M. Buenaventura, Joseph A. Cabaret, Aaron K. Calodney, Kenneth D. Candido, Cameron Cartier, Richard Latchaw, Sudhir Diwan, Ehren Dodson, Zachary Fausel, Michael Fredericson, Christopher G. Gharibo, Mayank Gupta, Adam M. Kaye, Nebojsa Nick Knezevic, Radomir Kosanovic, Matthew Lucas, Maanasa V. Manchikanti, R. Amadeus Mason, Kenneth Mautner, Samuel Murala, Annu Navani, Vidyasagar Pampati, Sarah Pastoriza, Ramarao Pasupuleti, Cyril Philip, Mahendra R Sanapati, Theodore Sand, Rinoo V Shah, Amol Soin, Ian Stemper, Bradley W Wargo, Philippe Hernigou

School of Pharmacy Faculty Articles

BACKGROUND: The use of bone marrow concentrate (BMC) for treatment of musculoskeletal disorders has become increasingly popular over the last several years, as technology has improved along with the need for better solutions for these pathologies. The use of cellular tissue raises a number of issues regarding the US Food and Drug Administration's (FDA) regulation in classifying these treatments as a drug versus just autologous tissue transplantation. In the case of BMC in musculoskeletal and spine care, this determination will likely hinge on whether BMC is homologous to the musculoskeletal system and spine.

OBJECTIVES: The aim of this review is …

Targeting Trna-Synthetase Interactions Towards Novel Therapeutic Discovery Against Eukaryotic Pathogens, Paul Kelly, Fatemeh Hadi-Nezhad, Dennis Y. Liu, Travis J. Lawrence, Roger G. Linington, Michael Ibba, David H. Ardell

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The development of chemotherapies against eukaryotic pathogens is especially challenging because of both the evolutionary conservation of drug targets between host and parasite, and the evolution of strain-dependent drug resistance. There is a strong need for new nontoxic drugs with broad-spectrum activity against trypanosome parasites such as Leishmania and Trypanosoma. A relatively untested approach is to target macromolecular interactions in parasites rather than small molecular interactions, under the hypothesis that the features specifying macromolecular interactions diverge more rapidly through coevolution. We computed tRNA Class-Informative Features in humans and independently in eight distinct clades of trypanosomes, identifying parasite-specific informative features, …

Synthesis And Preliminary Ex Vivo Testing Of Sirna Targeting Tcrb: A Proposed Therapy For The Treatment Of Autoimmunity, Nicholas J. Magazine

LSU Doctoral Dissertations

Abstract

Background:

As of 2018, the United States National Institutes of Health estimate that over half a billion people worldwide are affected by autoimmune disorders. Though these conditions are prevalent, treatment options remain relatively poor, relying primarily on various forms of immunosuppression which carry potentially severe side effects and often lose effectiveness overtime. Given this, new forms of therapy are needed. We propose small-interfering RNA (siRNA) for hypervariable regions of the T-cell receptor β-chain gene (TCRb) as a highly targeted, novel means of therapy for the treatment of autoimmune disorders.

Objectives:

To develop methods to produce siRNA targeting …

Eecp Improves Markers Of Functional Capacity Regardless Of Underlying Ranolazine Therapy, Sanaz Ziad, Jamil Malik, Obinna Isiguzo, Lang Xu, Leqi Chen, Annette Cox, Sachin Shah

School of Pharmacy Faculty Articles

OBJECTIVE: Enhanced external counterpulsation (EECP) and ranolazine are approved treatments for patients with chronic stable angina by the United States Food and Drug Administration (FDA). Whether EECP offers clinical benefits regardless of underlying ranolazine therapy needs further investigation.

METHODS: This was a retrospective evaluation of patients referred to a specialized EECP center. Patients having data on 6-Minute Walk Distance (6MWD) or Duke Activity Status Index (DASI) were categorized into two groups (EECP with ranolazine or EECP only). The primary endpoints were change in 6MWD and DASI before and after a full course of EECP within each of the two groups. …

Modulation Of K V 7 Channel Deactivation By Pi(4,5)P 2, Carlos A. Villalba-Galea

School of Pharmacy Faculty Articles

The activity of K_V7 channels critically contributes to the regulation of cellular electrical excitability in many cell types. In the central nervous system, the heteromeric K_V7.2/K_V7.3 channel is thought to be the chief molecular entity giving rise to M-currents. These K⁺-currents as so called because they are inhibited by the activation of Gq protein-coupled muscarinic receptors. In general, activation of Gq protein-coupled receptors (GqPCRs) decreases the concentration of the phosphoinositide PI(4,5)P₂ which is required for K_V7 channel activity. It has been recently reported that the deactivation rate of K …

Antifungal Defense Molecules From Bacterial Symbionts Of North American Trachymyrmex Ants, Georgia Scherer

CMC Senior Theses

Defensive symbioses, in which microbes provide molecular defenses for an animal host, hold great potential as untapped sources of therapeutically useful antibiotics. Fungus-growing ants use antifungal defenses from bacterial symbionts to suppress pathogenic fungi in their nests. Preliminary chemical investigations of symbiotic bacteria from this large family of ants have uncovered novel antifungal molecules with therapeutic potential, such as dentigerumycin and selvamicin.

In this study, the bacterial symbionts of North American Trachymyrmex fungus-growing ants are investigated for antifungal molecules. Plate-based bioassays using ecologically-relevant fungal pathogens confirmed that these bacteria have antifungal activity. In order to purify and identify the antifungal …

Characterizing Glycosaminoglycan And Glycosaminoglycan-Oligo Interactions With Cancer Stem Cells And Their Regulators, Rahaman Navaz Gangji

Theses and Dissertations

Tumor metastasis and recurrence account for more than 90% of cancer-associated deaths and are thought to occur due to a small subpopulation of neoplastic cells known as cancer stem cells (CSCs). Because CSCs are resistant to conventional chemotherapy, there is a critical need to develop CSC-targeting agents. Microenvironmental components, especially glycosaminoglycans (GAGs), play a key role in regulating CSC phenotype. GAGs such as heparan sulfate (HS) interact with hundreds of proteins and influence a variety of biological processes including tumor proliferation, angiogenesis, metastasis and stem cell biology.

Recently, the Desai and Patel laboratories have demonstrated that a hexasaccharide form of …

The Impact Of Aging And Mechanical Injury On Alveolar Epithelial And Macrophage Responses In Acute Lung Injury And Inflammation, Michael S. Valentine

Theses and Dissertations

Patients with severe lung pathologies, such as Acute Respiratory Distress Syndrome (ARDS), often require mechanical ventilation as a clinical intervention; however, this procedure frequently exacerbates the original pulmonary issue and produces an exaggerated inflammatory response that potentially leads to sepsis, multisystem organ failure, and mortality. This acute lung injury (ALI) condition has been termed Ventilator-Induced Lung Injury (VILI). Alveolar overdistension, cyclic atelectasis, and biotrauma are the primary injury mechanisms in VILI that lead to the loss of alveolar barrier integrity and pulmonary inflammation. Stress and strains during mechanical ventilation are believed to initiate alveolar epithelial mechanotransduction signaling mechanisms that contribute …

Engineering Hyaluronic Acid For Biomedical Applications, Deep S. Bhattacharya

Theses & Dissertations

This work presents research using the naturally available non- sulfated carbohydrate glycosaminoglycan hyaluronic acid (HA) for the synthesis of different chemical derivatives of HA for evaluation of binding kinetics with CD44 and P- selectin proteins for applications in fluorescence image-guided surgery. Chemical derivatives of HA such as deacetylated HA (deHA), sulfated HA (sHA), and deacetylated and sulfated HA (s-deHA) were synthesized by modulating sulfating and deacetylating reagents to alter binding specificities to CD44. Modified HA derivatives and CD44 biophysical interactions were assessed by fluorescence polarization. In silico techniques were also used to determine binding using molecular docking and MM-PBSA approaches. …

Alanyl-Trna Synthetase Quality Control Prevents Global Dysregulation Of The Escherichia Coli Proteome, Paul Kelly, Nicholas Backes, Kyle Mohler, Christopher Buser, Arundhati Kavoor, Jesse Rinehart, Gregory Phillips, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Mechanisms have evolved to prevent errors in replication, transcription, and translation of genetic material, with translational errors occurring most frequently. Errors in protein synthesis can occur at two steps, during tRNA aminoacylation and ribosome decoding. Recent advances in protein mass spectrometry have indicated that previous reports of translational errors have potentially underestimated the frequency of these events, but also that the majority of translational errors occur during ribosomal decoding, suggesting that aminoacylation errors are evolutionarily less tolerated. Despite that interpretation, there is evidence that some aminoacylation errors may be regulated, and thus provide a benefit to the cell, while others …

Alzheimer's And Amyloid Beta: Amyloidogenicity And Tauopathy Via Dyshomeostatic Interactions Of Amyloid Beta, Jordan Tillinghast

Senior Honors Theses

This paper reviews functions of Amyloid-β (Aβ) in healthy individuals compared to the consequences of aberrant Aβ in Alzheimer’s disease (AD). As extraneuronal Aβ accumulation and plaque formation are characteristics of AD, it is reasonable to infer a pivotal role for Aβ in AD pathogenesis. Establishing progress of the disease as well as the mechanism of neurodegeneration from AD have proven difficult (Selkoe, 1994). This thesis provides evidence suggesting the pathogenesis of AD is due to dysfunctional neuronal processes involving Aβ’s synaptic malfunction, abnormal interaction with tau, and disruption of neuronal homeostasis. Significant evidence demonstrates that AD symptoms are partially …

Production And Purification Of Basic Fibroblast Growth Factor Fused To Two Collagen Binding Domains Expressed In E. Coli Bl21 Using Flask And Fed-Batch, Hazim Aljewari

Graduate Theses and Dissertations

Delivering effective and non-toxic doses of bioactive materials that can aid in activating tissue regeneration to wounded tissue has proven to be an enormous challenge. This study was designed to produce a potential therapeutic recombinant protein by fusing two collagen binding domains to basic fibroblast growth factors (bFGF) through a collagenase cleavage site linker, so it can release the bFGF in a wound site by the action of this enzyme. The novel fusion protein was expressed in Escherichia coli BL-21 (E. coli) using traditional flask shaker and fed-batch cultivation. Cell lysate was purified by FPLC using Immobilized metal affinity chromatography …

Probing Of Carbohydrate-Protein Interactions Using Galactonoamidine Inhibitors, Jessica B. Pickens

Graduate Theses and Dissertations

Glycoside hydrolases are ubiquitous and one of the most catalytically proficient enzymes known, and thus understanding their mechanisms are crucial. Most research has focused on the interaction of the glycon of substrates and their inhibitors within the active site of glycoside hydrolases. The inhibitors employed to probe these interactions generally had small aglycons (i.e. a hydrogen atom, amidines, small aliphatic groups, or benzyl groups). Here, the interactions of the aglycon with glycoside hydrolases are examined by probing the active sites with a library of 25 galactonoamidines. The studies described in this dissertation aim to increase the understanding of stabilization of …

Toward Understanding The Mechanism Of Protein Targeting In The Chloroplast Signal Recognition Particle Pathway, Mercede Furr

Graduate Theses and Dissertations

Protein targeting is a vital cellular function. The signal recognition particle (SRP) pathway is a universally conserved targeting system present in the cytosol and used to co-translationally target many proteins to the inner membrane of prokaryotes and the endoplasmic reticulum of eukaryotes. The chloroplast has a homologous SRP system which post-translationally targets light harvesting chlorophyll binding proteins (LHCPs) to the thylakoid membrane for integration. The chloroplast SRP (cpSRP) is a heterodimer with a 54 kDa subunit equivalent to SRP54 in the canonical pathway. In addition, cpSRP contains a novel 43 kDa subunit which is a unique and irreplaceable component. cpSRP43 …

Global Acetylation Dynamics In The Heat Shock Response Of Saccharomyces Cerevisiae, Rebecca E. Hardman

Graduate Theses and Dissertations

All organisms face a constant barrage of environmental stresses. Single-cell organisms such as Saccharomyces cerevisiae, or common Baker’s yeast, must rely solely on cellular responses in order to survive. This response must occur in a rapid and highly coordinated manner to quickly inhibit all unnecessary processes and shuttle all available resources to those necessary for survival. One method that cells utilize for rapid protein regulation is the use of post-translational modifications. Enzymes within the cell add or remove a variety of chemical modifications, thus altering the local chemical environment of a protein. This creates a conformational change in the protein …

Single Molecule Fluorescence Studies Of Protein Structure And Dynamics Underlying The Chloroplast Signal Recognition Particle Targeting Pathway, Dustin R. Baucom

Graduate Theses and Dissertations

The work presented in this dissertation explores the structural dynamics in the chloroplast signal recognition particle pathway. Findings include cpSRP shows scanning functionality similar to that in the cytosolic SRP with the ribosome. The intrinsically disordered C-terminal tail of the Albino3 protein has some transient secondary structure. Upon binding to cpSRP43 in solution, separate secondary structure formation was identified in the C-terminal tail of Albino3. Finally, to increase efficiency of analyzing fluorescence time traces for this work, a modular software was produced.

Influence Of Single And Multiple Histidine Residues And Their Ionization Properties On Transmembrane Helix Dynamics, Orientations And Fraying, Fahmida Afrose

Graduate Theses and Dissertations

Since aromatic and charged residues are often present in various locations of transmembrane helices of integral membrane proteins, their impacts on the molecular properties of transmembrane proteins and their interactions with lipids are of particular interest in many studies. In this work, I used solid-state deuterium NMR spectroscopy in designed model peptide GWALP23 [GGALW(LA)6LWLAGA] with selective deuterium labels to addresses the pH dependence and influence of single and multiple “guest” histidine residues in the orientation and dynamic behaviors of transmembrane proteins. The mutations include Gly to His (G2/22 to H2/22), Trp to His (W5/19 to H5/19) and Leu to His …

How Oxygen Availability Affects The Antimicrobial Efficacy Of Host Defense Peptides: Lessons Learned From Studying The Copper-Binding Peptides Piscidins 1 And 3, Adenrele Oludiran, David S. Courson, Malia D. Stuart, Anwar R. Radwan, John C. Putsma, Myriam L. Cotten, Erin B. Purcell

Chemistry & Biochemistry Faculty Publications

The development of new therapeutic options against Clostridioides difficile (C. difficile) infection is a critical public health concern, as the causative bacterium is highly resistant to multiple classes of antibiotics. Antimicrobial host-defense peptides (HDPs) are highly effective at simultaneously modulating the immune system function and directly killing bacteria through membrane disruption and oxidative damage. The copper-binding HDPs piscidin 1 and piscidin 3 have previously shown potent antimicrobial activity against a number of Gram-negative and Gram-positive bacterial species but have never been investigated in an anaerobic environment. Synergy between piscidins and metal ions increases bacterial killing aerobically. Here, we …

Leaving Ligand Effects On Reactivity And Solubility Of Monofunctional Platinum(Ii) Anticancer Complexes, Heidi Linn Hruska Millay

Masters Theses & Specialist Projects

Monofunctional platinum(II) complexes, such as phenanthriplatin and pyriplatin, have notably different characteristics from the bifunctional anticancer complexes, such as cisplatin and oxaliplatin, which have detrimental toxicities and resistance associated with them. The unique properties of the monofunctional complexes may be exploited to target cancer cells without producing the toxic side effects associated with the current FDA-approved platinum-based anticancer drugs. To advance the understanding of these monofunctional platinum(II) complexes, this study replaced the chloride leaving ligand with an acetate group, which should increase solubility and alter the rate of reactivity with key amino acid and nucleotide targets. Phenanthriplatin and pyriplatin compounds …

The Fitness Landscape Of The African Salmonella Typhimurium St313 Strain D23580 Reveals Unique Properties Of The Pbt1 Plasmid, Rocío Canals, Roy R. Chaudhuri, Rebecca E. Steiner, Siân V. Owen, Natalia Quinones-Olvera, Melita A. Gordon, Michael Baym, Michael Ibba, Jay C. D. Hinton

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

We have used a transposon insertion sequencing (TIS) approach to establish the fitness landscape of the African Salmonella enterica serovar Typhimurium ST313 strain D23580, to complement our previous comparative genomic and functional transcriptomic studies. We used a genome-wide transposon library with insertions every 10 nucleotides to identify genes required for survival and growth in vitro and during infection of murine macrophages. The analysis revealed genomic regions important for fitness under two in vitro growth conditions. Overall, 724 coding genes were required for optimal growth in LB medium, and 851 coding genes were required for growth in SPI-2-inducing minimal medium. These …

Chemical Epitope Targeting: Review Of A Novel Screening Technology, Qurrat Ul-Ain, Rene Kandler, Dylan Gillespie, Arundhati Nag

Scholarly Undergraduate Research Journal at Clark (SURJ)

Chemical Epitope Targeting is a novel technology developed for designing peptide ligands with high affinity and specificity against specific regions of a protein that may be inaccessible to small molecules or antibodies. In this review, we summarize the key steps and significant applications of this technology. Operating on the same principles as antibody-antigen interactions, this technique involves chemically synthesizing the region of interest on the protein, called the epitope, as a polypeptide with a biotin detection tag and a strategically placed alkyne or azide presenting amino acid. The constructed epitope is screened against a comprehensive linear or cyclic One Bead …

Developing A Dissociative Nanocontainer For Peptide Drug Delivery, Michael Patrick Kelly

Dissertations, Theses, and Capstone Projects

The potency and specificity of bioactive peptides have propelled these agents to the forefront of pharmacological research. However, delivery of peptides to their molecular target in cells is a major obstacle to their widespread application. A Trojan Horse strategy of packaging a bioactive peptide within a modified protein cage to protect it during transport, and releasing it at the target site, is a promising delivery method. Recent work has demonstrated that the viral capsid of the P22 bacteriophage can be loaded with an arbitrary, genetically-encoded peptide, and externally decorated with a cell-penetrating peptide, such as HIV-Tat, to translocate across in …