Medicine and Health Sciences Commons^™

Effect Of Hydrogen Peroxide On The Biosynthesis Of Heme And Proteins: Potential Implications For The Partitioning Of Glu-TrnaGlu Between These Pathways, Carolina Farah, Gloria Levicán, Michael Ibba, Omar Orellana

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Glutamyl-tRNA (Glu-tRNA^Glu) is the common substrate for both protein translation and heme biosynthesis via the C5 pathway. Under normal conditions, an adequate supply of this aminoacyl-tRNA is available to both pathways. However, under certain circumstances, Glu-tRNA^Glu can become scarce, resulting in competition between the two pathways for this aminoacyl-tRNA. In Acidithiobacillus ferrooxidans, glutamyl-tRNA synthetase 1 (GluRS1) is the main enzyme that synthesizes Glu-tRNA^Glu. Previous studies have shown that GluRS1 is inactivated in vitro by hydrogen peroxide (H₂O₂). This raises the question as to whether H₂O₂ negatively affects …

Toxicity And Cosmesis Outcomes For Single Fraction Intra-Operative Electron Radiotherapy (Ioert) For Breast Cancer, Monica Hanna, Robert Ash, Wesley Babaran, Michele M. Carpenter, Afshin Forouzannia, Jay K. Harness, Brian Kaltenecker, Snehith Maddula, Venita Williams, Lawrence Wagman

Student Scholar Symposium Abstracts and Posters

Background: Adjuvant radiation therapy is proven to reduce local recurrence in patients with early stage breast cancer. To reduce toxicity, improve geographic accuracy, and reduce treatment time, IOERT can be utilized as an alternative to external beam radiation therapy. The study’s objective was to determine the short term toxicity and cosmesis profile of single fraction IOERT given as definitive treatment in a community setting. Materials and Methods: From Mar 2012 to Jul 2014, 84 patients (3 bilateral), ages 45-91 y.o. with stage 0-II were treated with IOERT (Mobetron, IntraOp Medical, Sunnyvale, CA). A single 21 Gy fraction was administered to …

Assessment Of The Effects Of Caffeine, Gallic Acid, And Epigallocatechin-3-Gallate On Cell Inhibition, Pim-3 And E. Cadherin Protein Levels In Two Lines Of Pancreatic Cancer Cells, Lena Haddad, Melissa Rowland-Goldsmith

Student Scholar Symposium Abstracts and Posters

According to the American Cancer Society, pancreatic cancer is currently the fourth leading cause of cancer related deaths in the United States. In addition to being an exceptionally aggressive form of cancer, it is particularly difficult to treat because it is usually diagnosed in late stages after the onset of metastasis (1). Consequently, the current treatments used, including chemotherapy and radiation, have been rendered ineffective (2). As a result, focus has been placed on using dietary alternatives which are known to possess chemopreventive properties (3). Previous studies have indicated that Gallic acid (an important phytochemical in pomegranates) and Epigallocatechin-3-Gallate (the …

Molecular Insights Into Prostate Field Cancerization: Telomere Length, Egr-­‐1 Expression, And Regulation Of Mic-­‐1, Pdgf-­‐A, And Fas, Emily Frisch, Kristin Gabriel, Marco Bisoffi

Student Scholar Symposium Abstracts and Posters

The diagnosis of prostate cancer (adenocarcinoma) relies on screening for elevated prostate-specific antigen (PSA) in blood samples and on digital rectal examination (DRE). With high PSA levels and/or abnormal DRE, physicians recommend a biopsy, which often misses the location of the adenocarcinoma and results in false negatives. Previous studies have shown expression of the key transcription factor early growth response 1 (EGR-1), the pro-survival factor macrophage inhibitor cytokine 1 (MIC-1), and the growth stimulatory platelet derived growth factor A (PDGF-A) to be up-regulated in histologically normal tissues 1 centimeter adjacent to prostate adenocarcinomas. We hypothesize that tumors emerge from “field …

Prostate Field Cancerization -- Thinking Outside The Tumor, Dor Shoshan, Marco Bisoffi

Student Scholar Symposium Abstracts and Posters

Prostate field cancerization (or field effect) is characterized by the presence of molecular alterations in histologically normal tissues adjacent to adenocarcinomas. Accordingly, our research indicates deregulated expression of several proteins that define this type of molecular pathology. The scope of the present study was to determine the expression of the key transcription factor and potential marker of field cancerization early growth response 1 (EGR-1) in human prostate tissues derived from prostatectomies and biopsy cores.

EGR-1 was detected by immunofluorescence using a polyclonal anti-human EGR-1 and Alexa Fluor 488-conjugated secondary antibodies. EGR-1 expression was quantitated by determining the pixel count per …

Engineered Plga Nanoparticles For Delivery Of Sirna In Mcf-7 Breast Cancer Cells, Sydney Pong, Samit Shah, Vivek Gupta

Student Scholar Symposium Abstracts and Posters

Small interfering RNAs have been an emerging medical treatment for molecular based diseases as they are capable of gene-specific knockdown. Appropriate and efficient delivery remains one of the biggest challenges in the development of siRNA as an anti-cancer treatment. Nanoparticles containing siRNA were characterized and the efficacy of various peptides in the transfection of the nanoparticles were tested. A gene silencing assay was developed in order to determine the effect of siRNA therapeutics on gene functionality in breast cancer cells.

Structure-Based Network Analysis Of Activation Mechanisms In The Erbb Family Of Receptor Tyrosine Kinases: The Regulatory Spine Residues Are Global Mediators Of Structural Stability And Allosteric Interactions, Kevin A. James, Gennady M. Verkhivker

Mathematics, Physics, and Computer Science Faculty Articles and Research

The ErbB protein tyrosine kinases are among the most important cell signaling families and mutation-induced modulation of their activity is associated with diverse functions in biological networks and human disease. We have combined molecular dynamics simulations of the ErbB kinases with the protein structure network modeling to characterize the reorganization of the residue interaction networks during conformational equilibrium changes in the normal and oncogenic forms. Structural stability and network analyses have identified local communities integrated around high centrality sites that correspond to the regulatory spine residues. This analysis has provided a quantitative insight to the mechanism of mutation-induced ‘‘superacceptor’’ activity …

Peptide Arrays For Detecting Naphthenic Acids In Oil Sands Process Affected Water, Kamaljit Kaur, Subir Bhattacharjee, Rajesh G. Pillai, Sahar Ahmed, Sarfuddin Azmi

Pharmacy Faculty Articles and Research

Naphthenic acids (NAs) are water-soluble components of petroleum. The characterization and quantification of NAs by analytical methods have proved quite challenging, whilst the toxic effects of these water-soluble compounds on a variety of organisms adversely affecting reproduction and steroid production is becoming apparent. In this study, we report a fluorescence-based competitive binding method for rapid sensing of the presence of NAs using cellulosic peptide array strips as sensors. The peptide array was designed from sequences derived from the estrogen receptor (ER). Several of these peptides were able to detect the presence of NAs at low micromolar (∼5 mg L^{−1 …}

The Non-Canonical Hydroxylase Structure Of Yfcm Reveals A Metal Ion-Coordination Motif Required For Ef-P Hydroxylation, Kan Kobayashi, Assaf Katz, Andrei Rajkovic, Ryohei Ishii, Owen E. Branson, Michael A. Freitas, Ryuichiro Ishitani, Michael Ibba, Osamu Nureki

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

EF-P is a bacterial tRNA-mimic protein, which accelerates the ribosome-catalyzed polymerization of poly-prolines. In Escherichia coli, EF-P is post-translationally modified on a conserved lysine residue. The post-translational modification is performed in a two-step reaction involving the addition of a β-lysine moiety and the subsequent hydroxylation, catalyzed by PoxA and YfcM, respectively. The β-lysine moiety was previously shown to enhance the rate of poly-proline synthesis, but the role of the hydroxylation is poorly understood. We solved the crystal structure of YfcM and performed functional analyses to determine the hydroxylation mechanism. In addition, YfcM appears to be structurally distinct from any …

Mapping Regions Of Rnf168 Required For Its Degradation By Icp0, Andrea Cyr, Matthew Weitzman

e-Research: A Journal of Undergraduate Work

Viruses establish infection by overtaking host cell processes and developing mechanisms that promote viral replication. Herpes simplex virus undergoes lytic and latent cycles of infection throughout the lifespan of its host. The viral genome is transcriptionally silent during latency, but viral proteins are produced upon reactivation. Herpes simplex virus type 1 encodes the ICP0 protein, an E3 ubiquitin ligase required for reactivation from latency of the infectious virus. The immediate-early protein ICP0 regulates the herpes simplex virus by activating viral gene expression thereby initiating lytic infection. Cellular proteins are degraded by ICP0, promoting the virus to enter the lytic cycle. …

Treating Cocaine Dependency With Psychopharmacotherapy And Behavioral Therapy, Robyn Liebman

e-Research: A Journal of Undergraduate Work

Cocaine is an addictive drug that affects more than 14 million people globally, according to the United Nations. This paper is a conceptual meta-analysis of numerous studies that tested the effects of psychopharmacological therapy along with behavioral therapy in the treatment of cocaine addiction. It is hypothesized that cocaine dependent individuals treated with a combination of psychopharmacological and behavioral therapies will be less likely to use cocaine. Measurements of cocaine use throughout the experiments were generally assessed by urine screenings. Results indicate that there is more evidence that a combination of psychopharmacological and behavioral therapies will reduce cocaine use. There …

The Effect Of Pomegranate Juice Extract On The Hedgehog Signaling Pathway In Pancreatic Cancer, Veronica Gomez, Talia Shackelford, Autumn Tocchi, Melissa Rowland-Goldsmith

e-Research: A Journal of Undergraduate Work

Pancreatic cancer is the fourth leading cause of cancer death in the United States. There have been several reports indicating that phytochemicals in fruits can reduce the risk of cancer due to the anti-oxidant and anti-inflammatory effects of the polyphenols. Our lab has shown that pomegranate juice extract (PJE) has anti-proliferative and pro-apoptotic effects in human pancreatic cancer cells. In the past, we have shown that cells adhere more strongly to the plate when treated with PJE. This observation prompted an investigation of how PJE regulates cell adhesion proteins. Previously, our lab investigated E-cadherin, a cell adhesion protein. Upon activation …

Mistranslation Of The Genetic Code, Adil Moghal, Kyle Mohler, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

During mRNA decoding at the ribosome, deviations from stringent codon identity, or “mistranslation,” are generally deleterious and infrequent. Observations of organisms that decode some codons ambiguously, and the discovery of a compensatory increase in mistranslation frequency to combat environmental stress have changed the way we view “errors” in decoding. Modern tools for the study of the frequency and phenotypic effects of mistranslation can provide quantitative and sensitive measurements of decoding errors that were previously inaccessible. Mistranslation with non‐protein amino acids, in particular, is an enticing prospect for new drug therapies and the study of molecular evolution.

Relaxed Substrate Specificity Leads To Extensive Trna Mischarging By Streptococcus Pneumoniae Class I And Class Ii Aminoacyl-Trna Synthetases, Jennifer Shepherd, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Aminoacyl-tRNA synthetases provide the first step in protein synthesis quality control by discriminating cognate from noncognate amino acid and tRNA substrates. While substrate specificity is enhanced in many instances by cis- and trans-editing pathways, it has been revealed that in organisms such as Streptococcus pneumoniae some aminoacyl-tRNA synthetases display significant tRNA mischarging activity. To investigate the extent of tRNA mischarging in this pathogen, the aminoacylation profiles of class I isoleucyl-tRNA synthetase (IleRS) and class II lysyl-tRNA synthetase (LysRS) were determined. Pneumococcal IleRS mischarged tRNA^Ile with both Val, as demonstrated in other bacteria, and Leu in a tRNA sequence-dependent …

Translation Initiation Rate Determines The Impact Of Ribosome Stalling On Bacterial Protein Synthesis, Steven J. Hersch, Sara Elgamal, Assaf Katz, Michael Ibba, William Wiley Navarre

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Ribosome stalling during translation can be caused by a number of characterized mechanisms. However, the impact of elongation stalls on protein levels is variable, and the reasons for this are often unclear. To investigate this relationship, we examined the bacterial translation elongation factor P (EF-P), which plays a critical role in rescuing ribosomes stalled at specific amino acid sequences including polyproline motifs. In previous proteomic analyses of both Salmonella and Escherichia coli efp mutants, it was evident that not all proteins containing a polyproline motif were dependent on EF-P for efficient expression in vivo . The α- and β-subunits of …

Ef-P Dependent Pauses Integrate Proximal And Distal Signals During Translation, Sara Elgamal, Assaf Katz, Steven J. Hersch, David Newsom, Peter White, William Wiley Navarre, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Elongation factor P (EF-P) is required for the efficient synthesis of proteins with stretches of consecutive prolines and other motifs that would otherwise lead to ribosome pausing. However, previous reports also demonstrated that levels of most diprolyl-containing proteins are not altered by the deletion of efp. To define the particular sequences that trigger ribosome stalling at diprolyl (PPX) motifs, we used ribosome profiling to monitor global ribosome occupancy in Escherichia coli strains lacking EF-P. Only 2.8% of PPX motifs caused significant ribosomal pausing in the Δefp strain, with up to a 45-fold increase in ribosome density observed at …

Sma-Causing Missense Mutations In Survival Motor Neuron (Smn) Display A Wide Range Of Phenotypes When Modeled In Drosophila, Kavita Praveen, Ying Wen, Kelsey M. Gray, John J. Noto, Akash R. Patlolla, Gregory D. Van Duyne, A. Gregory Matera

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Mutations in the human survival motor neuron 1 (SMN) gene are the primary cause of spinal muscular atrophy (SMA), a devastating neuromuscular disorder. SMN protein has a well-characterized role in the biogenesis of small nuclear ribonucleoproteins (snRNPs), core components of the spliceosome. Additional tissue-specific and global functions have been ascribed to SMN; however, their relevance to SMA pathology is poorly understood and controversial. Using Drosophila as a model system, we created an allelic series of twelve Smn missense mutations, originally identified in human SMA patients. We show that animals expressing these SMA-causing mutations display a broad range of …

Effects Of Pde4 Pathway Inhibition In Rat Experimental Stroke, Fan Yang, Rachita K. Sumbria, Dong Xue, Chuanhui Yu, Dan He, Shuo Liu, Annlia Paganini-Hill, Mark J. Fisher

Pharmacy Faculty Articles and Research

PURPOSE: The first genomewide association study indicated that variations in the phosphodiesterase 4D (PDE4D) gene confer risk for ischemic stroke. However, inconsistencies among the studies designed to replicate the findings indicated the need for further investigation to elucidate the role of the PDE4 pathway in stroke pathogenesis. Hence, we studied the effect of global inhibition of the PDE4 pathway in two rat experimental stroke models, using the PDE4 inhibitor rolipram. Further, the specific role of the PDE4D isoform in ischemic stroke pathogenesis was studied using PDE4D knockout rats in experimental stroke. METHODS: Rats were subjected to either the …

The Role Of Ape/Ref-1 In Hepatocellular Carcinoma Progression, Zhen Yang, Sun Yang, Bobbye J. Misner, Feng Liu-Smith, Frank L. Meyskens

Pharmacy Faculty Articles and Research

Hepatocellular carcinoma (HCC) is responsible for a third of the estimated cancer-caused deaths worldwide. To deeply understand the mechanisms controlling HCC progression is of primary importance to develop new approaches for treatment. Apurinic/apyrimidinic endonuclease-1/redox effector factor 1 (APE/Ref-1) has been uncovered elevated in various types of cancer, including HCC. Additionally, HCC progression is always correlated with elevated copper (Cu). Our previous data demonstrated that Cu treatment initiated APE/Ref-1 expression and its downstream targets. Therefore, we hypothesized that APE/Ref-1 may be involved in HCC progression through mediating the effect of Cu to its signaling cascades. Following different treatments, human HCC cell …

Trnas As Regulators Of Biological Processes, Medha Raina, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Transfer RNAs (tRNA) are best known for their role as adaptors during translation of the genetic code. Beyond their canonical role during protein biosynthesis, tRNAs also perform additional functions in both prokaryotes and eukaryotes for example in regulating gene expression. Aminoacylated tRNAs have also been implicated as substrates for non-ribosomal peptide bond formation, post-translational protein labeling, modification of phospholipids in the cell membrane, and antibiotic biosyntheses. Most recently tRNA fragments, or tRFs, have also been recognized to play regulatory roles. Here, we examine in more detail some of the new functions emerging for tRNA in a variety of cellular processes …

Oxidation Of Cellular Amino Acid Pools Leads To Cytotoxic Mistranslation Of The Genetic Code, Tammy J. Bullwinkle, Noah M. Reynolds, Medha Raina, Adil Moghal, Eleftheria Matsa, Andrei Rajkovic, Huseyin Kayadibi, Farbod Fazlollahi, Christopher Ryan, Nathaniel Howitz, Kym F. Faull, Beth A. Lazazzera, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Aminoacyl-tRNA synthetases use a variety of mechanisms to ensure fidelity of the genetic code and ultimately select the correct amino acids to be used in protein synthesis. The physiological necessity of these quality control mechanisms in different environments remains unclear, as the cost vs benefit of accurate protein synthesis is difficult to predict. We show that in Escherichia coli, a non-coded amino acid produced through oxidative damage is a significant threat to the accuracy of protein synthesis and must be cleared by phenylalanine-tRNA synthetase in order to prevent cellular toxicity caused by mis-synthesized proteins. These findings demonstrate how stress …

Reduced Amino Acid Specificity Of Mammalian Tyrosyl-Trna Synthetase Is Associated With Elevated Mistranslation Of Tyr Codons, Medha Raina, Adil Moghal, Amanda Kano, Mathew Jerums, Paul D. Schnier, Shun Luo, Rohini Deshpande, Pavel D. Bondarenko, Henry Lin, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Quality control operates at different steps in translation to limit errors to approximately one mistranslated codon per 10,000 codons during mRNA-directed protein synthesis. Recent studies have suggested that error rates may actually vary considerably during translation under different growth conditions. Here we examined the misincorporation of Phe at Tyr codons during synthesis of a recombinant antibody produced in tyrosine-limited Chinese hamster ovary (CHO) cells. Tyr to Phe replacements were previously found to occur throughout the antibody at a rate of up to 0.7% irrespective of the identity or context of the Tyr codon translated. Despite this comparatively high mistranslation rate, …

The Abcs Of The Ribosome, Kurt Fredrick, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

An ABC protein that binds the ribosomal exit site suggests a new mechanism for direct regulation of translation in response to changing ATP levels in the cell.

Beta-Alanine Suppresses Malignant Breast Epithelial Cell Aggressiveness Through Alterations In Metabolism And Cellular Acidity In Vitro, Roger A. Vaughan, Nicholas P. Gannon, Randi Garcia-Smith, Yamhilette Licon-Munoz, Miguel A. Barberena, Marco Bisoffi, Kristina A. Trujillo

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Background: Deregulated energetics is a property of most cancer cells. This phenomenon, known as the Warburg Effect or aerobic glycolysis, is characterized by increased glucose uptake, lactate export and extracellular acidification, even in the presence of oxygen. beta-alanine is a non-essential amino acid that has previously been shown to be metabolized into carnosine, which functions as an intracellular buffer. Because of this buffering capacity, we investigated the effects of beta-alanine on the metabolic cancerous phenotype.

Methods: Non-malignant MCF-10a and malignant MCF-7 breast epithelial cells were treated with beta-alanine at 100 mM for 24 hours. Aerobic glycolysis was quantified …

Structure-Functional Prediction And Analysis Of Cancer Mutation Effects In Protein Kinases, Anshuman Dixit, Gennady M. Verkhivker

Mathematics, Physics, and Computer Science Faculty Articles and Research

A central goal of cancer research is to discover and characterize the functional effects of mutated genes that contribute to tumorigenesis. In this study, we provide a detailed structural classification and analysis of functional dynamics for members of protein kinase families that are known to harbor cancer mutations. We also present a systematic computational analysis that combines sequence and structure-based prediction models to characterize the effect of cancer mutations in protein kinases. We focus on the differential effects of activating point mutations that increase protein kinase activity and kinase-inactivating mutations that decrease activity. Mapping of cancer mutations onto the conformational …

Synthesis And Evaluation Of Antiproliferative Activity Of Substituted N-(9-Oxo-9h-Xanthen-4-Yl)Benzenesulfonamides, Somayeh Motavallizadeh, Asal Fallah-Tafti, Saeedeh Maleki, Amir Nasrolahi Shirazi, Mahboobeh Pordeli, Maliheh Safavi, Sussan Kabudanian Ardestani, Shaaban Asd, Rakesh Tiwari, Donghoon Oh, Abbas Shafiee, Alireza Foroumadi, Keykavous Parang, Tahmineh Akbarzadeh

Pharmacy Faculty Articles and Research

Several novel N-(9-oxo-9H-xanthen-4-yl)benzenesulfonamides derivatives were prepared as potential antiproliferative agents. The in vitro antiproliferative activity of the synthesized compounds was investigated against a panel of tumor cell lines including breast cancer cell lines (MDA-MB-231, T-47D) and neuroblastoma cell line (SK-N-MC) using MTT colorimetric assay. Etoposide, a well-known anticancer drug, was used as a positive standard drug. Among synthesized compounds, 4-methoxy-N-(9-oxo-9H-xanthen-4-yl)benzenesulfonamide (5i) showed the highest antiproliferative activity against MDA-MB-231, T-47D, and SK-N-MC cells. Furthermore, pentafluoro derivatives 5a and 6a exhibited higher antiproliferative activity than doxorubicin against human leukemia cell line (CCRF-CEM) and breast adenocarcinoma (MDAMB- 468) cells. Structure-activity relationship studies revealed …

Parent-Metabolite Pharmacokinetic Models For Tramadol – Tests Of Assumptions And Predictions, Sam Holford, Karel Allegaert, Brian J. Anderson, Butch Kukanich, Altamir B. Sousa, Amir Steinman, Bruno Pypendop, Reza Mehvar, Mario Giorgi, Nick Holford

Pharmacy Faculty Articles and Research

Allometric principles were used to discern cross-species differences in (±)-tramadol disposition and formation of its primary analgesic metabolite, (±)-O-desmethyl-tramadol (M1). Species differences in formation of M1 may help predict the analgesic effectiveness of tramadol. Tramadol was administered intravenously by a zero-order (constant infusion) process or rapid bolus dose and racemic concentrations of tramadol and M1 measured. Data were pooled to define differences between species (human, rat, cat, dog, goat, donkey and horse). A two-compartment linear disposition model with first-order elimination was used to describe tramadol and M1 disposition. Slow metabolizers were detected in 6% of the population and tramadol clearance …

Synthesis And Evaluation Of C-Src Kinase Inhibitory Activity Of Pyridin-2(1h)-One Derivatives, Karam Chand, Suchita Prasad, Rakesh Tiwari, Amir Nasrolahi Shirazi, Sumit Kumar, Keykavous Parang, Sunil K. Sharma

Pharmacy Faculty Articles and Research

Src kinase, a prototype member of the Src family of kinases (SFKs), is over-expressed in various human tumors, and has become a target for anticancer drug design. In this perspective, a series of eighteen 2-pyridone derivatives were synthesized and evaluated for their c-Src kinase inhibitory activity. Among them, eight compounds exhibited c-Src kinase inhibitory activity with IC50 value of less than 25 mu M. Compound 1-[2-(dimethylamino)ethyl]-5-(2-hydroxy-4-methoxybenzoyl)pyridin-2(1H)-one (36) exhibited the highest c-Src kinase inhibition with an IC50 value of 12.5 mu M. Furthermore, the kinase inhibitory activity of compound 36 was studied against EGFR, MAPK and PDK, however no significant activity …

Simultaneous Bactericidal And Osteogenic Effect Of Nanoparticulate Calcium Phosphate Powders Loaded With Clindamycin On Osteoblasts Infected With Staphylococcus Aureus, Vuk Uskoković, Tejal A. Dasai

Pharmacy Faculty Articles and Research

S aureus internalized by bone cells and shielded from the immune system provides a reservoir of bacteria in recurring osteomyelitis. Its targeting by the antibiotic therapy may thus be more relevant for treating chronic bone infection than eliminating only the pathogens colonizing the bone matrix. Assessed was the combined osteogenic and antibacterial effect of clindamycinloaded calcium phosphate nanoparticles of different monophasic compositions on co-cultures comprising osteoblasts infected with S aureus. Antibiotic-carrying particles were internalized by osteoblasts and minimized the concentration of intracellular bacteria. In vitro treatments of the infected cells, however, could not prevent cell necrosis due to the …

Allosteric Regulation Of The Hsp90 Dynamics And Stability By Client Recruiter Cochaperones: Protein Structure Network Modeling, Kristin Blacklock, Gennady M. Verkhivker

Mathematics, Physics, and Computer Science Faculty Articles and Research

The fundamental role of the Hsp90 chaperone in supporting functional activity of diverse protein clients is anchored by specific cochaperones. A family of immune sensing client proteins is delivered to the Hsp90 system with the aid of cochaperones Sgt1 and Rar1 that act cooperatively with Hsp90 to form allosterically regulated dynamic complexes. In this work, functional dynamics and protein structure network modeling are combined to dissect molecular mechanisms of Hsp90 regulation by the client recruiter cochaperones. Dynamic signatures of the Hsp90-cochaperone complexes are manifested in differential modulation of the conformational mobility in the Hsp90 lid motif. Consistent with the experiments, …