Medicine and Health Sciences Commons^™

An Archaeal Trna-Synthetase Complex That Enhances Aminoacylation Under Extreme Conditions, Vlatka Godinic-Mikulcic, Jelena Jaric, Corinne D. Hausmann, Michael Ibba, Ivana Weygand-Durasevic

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Aminoacyl-tRNA synthetases (aaRSs) play an integral role in protein synthesis, functioning to attach the correct amino acid with its cognate tRNA molecule. AaRSs are known to associate into higher-order multi-aminoacyl-tRNA synthetase complexes (MSC) involved in archaeal and eukaryotic translation, although the precise biological role remains largely unknown. To gain further insights into archaeal MSCs, possible protein-protein interactions with the atypical Methanothermobacter thermautotrophicus seryl-tRNA synthetase (MtSerRS) were investigated. Yeast two-hybrid analysis revealed arginyl-tRNA synthetase (MtArgRS) as an interacting partner of MtSerRS. Surface plasmon resonance confirmed stable complex formation, with a dissociation constant (KD) of 250 nm. Formation of the MtSerRS·MtArgRS complex …

Synthesis And Analytical Evaluation Of Folate Conjugates For Use In Cancer Cell Detection, Sneha Reddy Kuthuru

All Capstone Projects

Recent clinical studies have shown the importance of folate receptor in drug delivery system as they increase the potency and reduce toxicity of many cancer therapies. The folate receptor alpha ( FR-a) binds with high affinity for folic acid and serves for receptor mediated transport of folate into cells. Folate is necessary for DNA metabolism and thus it is speculated that rapidly dividing cancer cells have an increased requirement for folic acid. It is known that FR-a levels are elevated in specific malignant diseases (solid tumors, leukemia) and thus the FR receptor serves as useful targeting moiety for the diagnosis …

Total Protein Determination Using Micro Plate Assay, Julie Ruffatti

All Capstone Projects

One of the largest challenges that food manufactures are facing today is the management of food allergens. Allergenic protein in trace amounts, part per million concentrations, will trigger a reaction in some individuals. Food manufacturers need to prevent allergen cross-contamination by performing adequate sanitation after production of an allergenic containing food. Allergen detection kits are used to determine if sufficient protein was removed from the equipment surfaces during sanitation. One kit on the market is the 3M™ Clean- Trace™ Surface Protein (Allergen) swab tests. The test qualitatively detects the presence of protein based on the biuret reaction and will yield …

High Pressure Liquid Chromatography Studies Of The Reaction Of Platinum Complexes With Peptides, Khaja Muneeruddin

Masters Theses & Specialist Projects

Platinum complexes (cisplatin, carboplatin and oxaliplatin) are effective anticancer agents. However the major drawbacks of platinum chemotherapy are toxic side effects and resistance. The affinity of platinum complexes to sulfur donor ligands of side chains of methionine and cysteine amino acids was assumed to be responsible for toxicity and resistance. Recently, it was found that the reaction of platinum complex with proteins containing sulfur donor ligands could actually favor its anticancer activity. Copper transporter 1 (Ctr 1), a protein involved in the transport of copper into the cell, also helps in the influx of cisplatin by binding to N-terminal domain …

Poxa, Yjek And Elongation Factor P Coordinately Modulate Virulence And Drug Resistance In Salmonella Enterica, William Wiley Navarre, Shicong Zou, Hervé Roy, Jinglin Lucy Xie, Alexei Savchenko, Alexander Singer, Elena Edvokimova, Lynne R. Prost, Runjun Kumar, Michael Ibba, Ferric C. Fang

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

We report an interaction between poxA, encoding a paralog of lysyl tRNA-synthetase, and the closely linked yjeK gene, encoding a putative 2,3-β-lysine aminomutase, that is critical for virulence and stress resistance in Salmonella enterica. Salmonella poxA and yjeK mutants share extensive phenotypic pleiotropy, including attenuated virulence in mice, an increased ability to respire under nutrient-limiting conditions, hypersusceptibility to a variety of diverse growth inhibitors, and altered expression of multiple proteins, including several encoded on the SPI-1 pathogenicity island. PoxA mediates posttranslational modification of bacterial elongation factor P (EF-P), analogous to the modification of the eukaryotic EF-P homolog, eIF5A, with …

Redox Status Affects The Catalytic Activity Of Glutamyl-Trna Synthetase, Assaf Katz, Ranat Banerjee, Merly De Armas, Michael Ibba, Omar Orellana

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Glutamyl-tRNA synthetases (GluRS) provide Glu-tRNA for different processes including protein synthesis, glutamine transamidation and tetrapyrrole biosynthesis. Many organisms contain multiple GluRSs, but whether these duplications solely broaden tRNA specificity or also play additional roles in tetrapyrrole biosynthesis is not known. Previous studies have shown that GluRS1, one of two GluRSs from the extremophile Acidithiobacillus ferrooxidans, is inactivated when intracellular heme is elevated suggesting a specific role for GluRS1 in the regulation of tetrapyrrole biosynthesis. We now show that, in vitro, GluRS1 activity is reversibly inactivated upon oxidation by hemin and hydrogen peroxide. The targets for oxidation-based inhibition were …

Ricin B Chain-Insulin Fusion Protein Immunomodulation Of Type 1 Diabetes, James Edward Carter Iii

Loma Linda University Electronic Theses, Dissertations & Projects

Type 1 diabetes mellitus (T1D) is a debilitating chronic inflammatory disease of the insulin-producing pancreatic islet β-cells that results from a combination of genetic and environmental factors. Attempts to suppress Th1-mediated autoimmune diseases such as T1D by mucosal delivery of autoantigens for immunotolerization have yielded only partial success. Attainment of satisfactory levels of sustained immunological tolerance remains to be accomplished. To restore self-tolerance requires delivery of sufficient amounts of autoantigen to stimulate regulatory T helper cells that function to survey the gut and induce tolerance to consumed antigens such as food. Oral delivery of autoantigens has previously been shown to …

Protein Evolution Via Amino Acid And Codon Elimination, Lise Goltermann, Marie Sofie Yoo Larsen, Ranat Banerjee, Andreas C. Joerger, Michael Ibba, Thomas Bentin

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Background
Global residue-specific amino acid mutagenesis can provide important biological insight and generate proteins with altered properties, but at the risk of protein misfolding. Further, targeted libraries are usually restricted to a handful of amino acids because there is an exponential correlation between the number of residues randomized and the size of the resulting ensemble. Using GFP as the model protein, we present a strategy, termed protein evolution via amino acid and codon elimination, through which simplified, native-like polypeptides encoded by a reduced genetic code were obtained via screening of reduced-size ensembles.

Methodology/Principal Findings
The strategy involves combining a sequential …

How The Sequence Of A Gene Can Tune Its Translation, Kurt Fredrick, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Sixty-one codons specify 20 amino acids, offering cells many options for encoding a polypeptide sequence. Two new studies (Cannarrozzi et al., 2010, Tuller et al., 2010) now foster the idea that patterns of codon usage can control ribosome speed, fine-tuning translation to increase the efficiency of protein synthesis.

Distribution Of Allatostatin C-Like Immunoreactivity In The Central Nervous System Of The Copepod Crustacean Calanus Finmarchicus, Caroline H. Wilson, Andrew E. Christie

Health Sciences and Kinesiology Faculty Articles

The C-type allatostatins (C-ASTs) are a family of highly pleiotropic arthropod neuropeptides. In crustaceans, transcriptomic/mass spectral studies have identified C-ASTs in the nervous systems of many species; the cellular distributions of these peptides remain unknown. Here, the distribution of C-AST was mapped in the nervous system of the copepod Calanus finmarchicus, the major contributor to the North Atlantic’s zooplanktonic biomass; C-AST-immunopositive neurons were identified in the protocerebrum, in several peripheral ganglia associated with feeding appendages, and in the ganglia controlling the swimming legs, with immunopositive axons present throughout the ventral nerve cord. In addition, axons innervating the dorsal longitudinal …

4 Part Research Project: Cholecystokinin, Marcie Tasker

Academic Symposium of Undergraduate Scholarship

This 4 part research paper contains information on the biological molecule Cholecystokinin. The following research discusses and presents evidence of the name, history and structure of the hormone. It also discusses the different chemical reactions Cholecystokinin has in the body, the biological roles of Cholecystokinin and the importance of Cholecystokinin focusing specifically on the unexplained obesity issue of our world.

Interconversion Of The Specificities Of Human Lysosomal Enzymes, Ivan B. Tomasic

Masters Theses 1911 - February 2014

Fabry disease (FD) is an X-linked recessive lysosomal storage disorder (LSD) known to affect approximately 1 in every 40,000 males, and a smaller number of females. FD results from a deficiency of functional α-galactosidase (α-GAL), which leads to the accumulation of terminally α-galactosylated substrates in the lysosome. The predominant treatment is Enzyme Replacement Therapy (ERT), requiring the regular infusion of recombinant human α-GAL. More than half of individuals receiving ERT experience a range of adverse infusion reactions, and it has been reported that as many as 88% of patients receiving ERT develop neutralizing IgG antibodies against the drug.

In aim …

Differential Impact Of Tumor Suppressor Pathways On Dna Damage Response And Therapy-Induced Transformation In A Mouse Primary Cell Model., A Kathleen Mcclendon, Jeffry L Dean, Adam Ertel, Erik S Knudsen

Department of Cancer Biology Faculty Papers

The RB and p53 tumor suppressors are mediators of DNA damage response, and compound inactivation of RB and p53 is a common occurrence in human cancers. Surprisingly, their cooperation in DNA damage signaling in relation to tumorigenesis and therapeutic response remains enigmatic. In the context of individuals with heritable retinoblastoma, there is a predilection for secondary tumor development, which has been associated with the use of radiation-therapy to treat the primary tumor. Furthermore, while germline mutations of the p53 gene are critical drivers for cancer predisposition syndromes, it is postulated that extrinsic stresses play a major role in promoting varying …

Impaired M3 And Enhanced M2 Muscarinic Receptor Contractile Function In A Streptozotocin Model Of Mouse Diabetic Urinary Bladder, K. J. Pak, Rennolds S. Ostrom, M. Matsui, F. J. Ehlert

Pharmacy Faculty Articles and Research

We investigated the contractile roles of M2 and M3 muscarinic receptors in urinary bladder from streptozotocin-treated mice. Wild-type and M2 muscarinic receptor knockout (M2 KO) mice were given a single injection of vehicle or streptozotocin (125 mg kg−1) 2–24 weeks prior to bladder assays. The effect of forskolin on contractions elicited to the muscarinic agonist, oxotremorine-M, was measured in isolated urinary bladder (intact or denuded of urothelium). Denuded urinary bladder from vehicle-treated wild-type and M2 KO mice exhibited similar contractile responses to oxotremorine-M, when contraction was normalized relative to that elicited by KCl (50 mM). Eight to 9 weeks after …

Plasma Pharmacokinetics And Tissue Disposition Of Novel Dextran- Methylprednisolone Conjugates With Peptide Linkers In Rats, Suman Penugonda, Hitesh K. Agarwal, Keykavous Parang, Reza Mehvar

Pharmacy Faculty Articles and Research

The plasma and tissue disposition of two novel dextran prodrugs of methylprednisolone (MP) containing one (DMP-1) or five (DMP-5) amino acids as linkers were studied in rats. Single 5-mg/kg doses (MP equivalent) of each prodrug or MP were administered intravenously, and blood and tissue samples were collected. Prodrug and drug concentrations were quantitated using HPLC, and noncompartmental pharmacokinetic parameters were estimated. Whereas conjugation of MP with dextran in both prodrugs substantially decreased the clearance of the drug by ∼200-fold, the accumulations of the drug in the liver, spleen, and kidneys were significantly increased by conjugation. However, the extent of accumulation …

Hcmv Pus28 Initiates Pro-Migratory Signaling Via Activation Of Pyk2 Kinase, Jennifer Totonchy, Susan Varnum, Ryan Melnychuk, Patricia Smith, Ljiliana Pasa-Tolic, Janani I. Shutthanadan, Daniel N. Streblow

Pharmacy Faculty Articles and Research

Background: Human Cytomegalovirus (HCMV) has been implicated in the acceleration of vascular disease and chronic allograft rejection. Recently, the virus has been associated with glioblastoma and other tumors. We have previously shown that the HCMV-encoded chemokine receptor pUS28 mediates smooth muscle cell (SMC) and macrophage motility and this activity has been implicated in the acceleration of vascular disease. pUS28 induced SMC migration involves the activation of the protein tyrosine kinases (PTKs) Src and Focal adhesion kinase as well as the small GTPase RhoA. The PTK Pyk2 has been shown to play a role in cellular migration and formation of cancer, …

Synthesis And Evaluation Of Conformationally Constrained Peptide Analogues As The Src Sh3 Domain Binding Ligands, Rakesh Tiwari, Alex Brown, Seetha Narramaneni, Gongqin Sun, Keykavous Parang

Pharmacy Faculty Articles and Research

Src kinase activity is regulated by the interaction of SH3 domain with protein sequences that are rich in proline residues. Identification of more potent SH3 domain binding ligands that can regulate Src kinase activity is a subject of major interest. Conformationally constrained peptides have been previously used for improving the binding potency of the Src SH2 domain binding peptide ligands and peptide substrates of the substrate-binding site of Src. A series of peptide analogues of Ac-VSLARRPLPPLP (1, Ac-VSL-12, Kd = 0.34 M) were synthesized by introducing conformational constraints to improve the binding affinity towards the Src SH3 domain. Peptides synthesized …

Prospects And Pits On The Path Of Biomimetics: The Case Of Tooth Enamel, Vuk Uskoković

Pharmacy Faculty Articles and Research

This review presents a discourse on challenges in understanding and imitating the process of amelogenesis in vitro on the molecular scale. In light of the analysis of imitation of the growth of dental enamel, it also impends on the prospects and potential drawbacks of the biomimetic approach in general. As the formation of enamel proceeds with the protein matrix guiding the crystal growth, while at the same time conducting its own degradation and removal, it is argued that three aspects of amelogenesis need to be induced in parallel: a) crystal growth; b) protein assembly; c) proteolytic degradation. A particular emphasis …

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 …

Prostate Cancer Region Prediction Using Maldi Mass Spectra, Ayyappa Vadlamudi, Shao-Hui Chuang, Xiaoyan Sun, Lisa Cazares, Julius Nyalwidhe, Dean Troyer, O. John Semmes, Jiang Li, Frederic D. Mckenzie

Electrical & Computer Engineering Faculty Publications

For the early detection of prostate cancer, the analysis of the Prostate-specific antigen (PSA) in serum is currently the most popular approach. However, previous studies show that 15% of men have prostate cancer even their PSA concentrations are low. MALDI Mass Spectrometry (MS) proves to be a better technology to discover molecular tools for early cancer detection. The molecular tools or peptides are termed as biomarkers. Using MALDI MS data from prostate tissue samples, prostate cancer biomarkers can be identified by searching for molecular or molecular combination that can differentiate cancer tissue regions from normal ones. Cancer tissue regions are …

Adjacent Slice Prostate Cancer Prediction To Inform Maldi Imaging Biomarker Analysis, Shao-Hui Chuang, Xiaoyan Sun, Lisa Cazares, Julius Nyalwidhe, Dean Troyer, O. John Semmes, Jiang Li, Frederic D. Mckenzie, Nico Karssemeijer (Ed.), Ronald M. Summers (Ed.)

Electrical & Computer Engineering Faculty Publications

Prostate cancer is the second most common type of cancer among men in US [1]. Traditionally, prostate cancer diagnosis is made by the analysis of prostate-specific antigen (PSA) levels and histopathological images of biopsy samples under microscopes. Proteomic biomarkers can improve upon these methods. MALDI molecular spectra imaging is used to visualize protein/peptide concentrations across biopsy samples to search for biomarker candidates. Unfortunately, traditional processing methods require histopathological examination on one slice of a biopsy sample while the adjacent slice is subjected to the tissue destroying desorption and ionization processes of MALDI. The highest confidence tumor regions gained from the …