Biochemistry Commons^™

Culturable Aerobic And Facultative Anaerobic Intestinal Bacterial Flora Of Black Cobra (Naja Naja Karachiensis) In Southern Pakistan, Junaid Iqbal, Mehwish Sagheer, Nazneen Tabassum, Ruqaiyyah Siddiqui, Naveed Ahmed Khan

Department of Biological & Biomedical Sciences

Using morphological analysis and biochemical testing, here for the first time, we determined the culturable gut bacterial flora (aerobes and facultative anaerobes) in the venomous Black Cobra (Naja naja karachiensis) from South Asia. The findings revealed that these snakes inhabit potentially pathogenic bacteria including Serratia marcescens, Pseudomonas aeruginosa, Shewanella putrefaciens, Aeromonas hydrophila, Salmonella sp., Moraxella sp., Bacillus sp., Ochrobactrum anthropi, and Providencia rettgeri. These findings are of concern, as injury from snake bite can result in wound infections and tissue necrosis leading to sepsis/necrotizing fasciitis and/or expose consumers of snake meat/medicine in the community to infections.

Synthesis And Characterization Of Pt(Ii) Complexes For Anticancer Therapy, Mihaela A. Ciulei, Pradip K. Bhowmik

McNair Poster Presentations

The first platinum-based drug was discovered and approved by Food and Drug Administration (FDA) in 1978 is cis-diamminedichloroplatinum (II) (cisplatin or CDDP). Cisplatin is used for about 50% of the chemotherapeutic cancer treatments along with its two analogues carboplatin and oxaliplatin. So far these drugs have been used extensively as treatment for ovarian, bladder, head and neck, and lung cancers. Although cisplatin has been used so often, it has toxic side effects and drug resistance.1-4 Due to these limitations other compounds have been synthesized. Specifically, our lab in conjunction with a biochemistry lab has recently published one article …

A Loose Domain Swapping Organization Confers A Remarkable Stability To The Dimeric Structure Of The Arginine Binding Protein From Thermotoga Maritima, Alessia Ruggiero, Jonathan D. Dattelbaum, Maria Staiano, Rita Berisio, Sabato D'Auria, Luigi Vitagliano

Chemistry Faculty Publications

The arginine binding protein from Thermatoga maritima (TmArgBP), a substrate binding protein (SBP) involved in the ABC system of solute transport, presents a number of remarkable properties. These include an extraordinary stability to temperature and chemical denaturants and the tendency to form multimeric structures, an uncommon feature among SBPs involved in solute transport. Here we report a biophysical and structural characterization of the TmArgBP dimer. Our data indicate that the dimer of the protein is endowed with a remarkable stability since its full dissociation requires high temperature as well as SDS and urea at high concentrations. In order to elucidate …

Bipolar Nanosecond Electric Pulses Are Less Efficient At Electropermeabilization And Killing Cells Than Monopolar Pulses, Bennett L. Ibey, Olga N. Pakhomova, Caleb C. Roth, Shu Xiao, Karl Schoenbach, Andrei G. Pakhomov

Bioelectrics Publications

Multiple studies have shown that bipolar (BP) electric pulses in the microsecond range are more effective at permeabilizing cells while maintaining similar cell survival rates as compared to monopolar (MP) pulse equivalents. In this paper, we investigated whether the same advantage existed for BP nanosecond-pulsed electric fields (nsPEF) as compared to MP nsPEF. To study permeabilization effectiveness, MP or BP pulses were delivered to single Chinese hamster ovary (CHO) cells and the response of three dyes, Calcium Green-1, propidium iodide (PI), and FM1-43, was measured by confocal microscopy. Results show that BP pulses were less effective at increasing intracellular calcium …

Enzyme Optimization For Lignocellulose Hydrolysis Using Mechanistic Modeling, Adam S. Marlowe

Dissertations, Master's Theses and Master's Reports - Open

A novel mechanistic model for the saccharification of cellulose and hemicellulose is utilized to predict the products of hydrolysis over a range of enzyme loadings and times. The mechanistic model considers the morphology of the substrate and the kinetics of enzymes to optimize enzyme concentrations for the enzymatic hydrolysis of cellulose and hemicellulose simultaneously. Substrates are modeled based on their fraction of accessible sites, glucan content, xylan content, and degree of polymerizations. This enzyme optimization model takes into account the kinetics of six core enzymes for lignocellulose hydrolysis: endoglucanase I (EG1), cellobiohydrolase I (CBH1), cellobiohydrolase II (CBH2), and endo-xylanase (EX) …

Single-Molecule Analysis Of Alzheimer's Β-Peptide Oligomer Disassembly At Physiological Concentration, Chen Chen

Theses and Dissertations--Chemistry

The diffusible soluble oligomeric amyloid β-peptide (Aβ) has been identified as a toxic agent in Alzheimer’s disease that can cause synaptic dysfunction and memory loss, indicating its role as potential therapeutic targets for AD treatment. Recently an oligomer-specific sandwich biotin-avidin interaction based assay identified the Aβ oligomer dissociation potency of a series of dihydroxybenzoic acid (DHBA) isomers. Because the sandwich assay is an ensemble method providing limited size information, fluorescence correlation spectroscopy (FCS) was employed to provide single molecule resolution of the disassembly mechanism.

Using FCS coupled with atomic force microscopy, we investigated the size distribution of fluorescein labeled synthetic …

Stability Studies Of Membrane Proteins, Cui Ye

Theses and Dissertations--Chemistry

The World Health Organization has identified antimicrobial resistance as one of the top three threats to human health. Gram-negative bacteria such as Escherichia coli are intrinsically more resistant to antimicrobials. There are very few drugs either on the market or in the pharmaceutical pipeline targeting Gram-negative pathogens. Two mechanisms, the protection of the outer membrane and the active efflux by the multidrug transporters, play important roles in conferring multidrug resistance to Gram-negative bacteria. My work focuses on two main directions, each aligning with one of the known multidrug resistance mechanisms.

The first direction of my research is in the area …

Increase Of Basal Oxidative Stress Levels And Impairment Of Heme Oxygenase-1/Biliverdin Reductase Post-Translational Modification By The Defect Of Parkinson-Related Gene Of Pink1, Zhaoshu Zhang

Theses and Dissertations--Chemistry

Parkinson disease (PD) is the most common movement disorder and the second most common neurodegenerative disease. PINK1, PTEN-induced kinase 1, functions as a serine/threonine kinase as well as a protector of mitochondrial function. Mutations in PINK1 gene result in either mitochondria dysfunction or disruption of kinase signaling pathways involved in the pathogenesis of PD.

In this thesis, oxidative stress levels were examined in the brain of PINK1 knockout mice, and also how heme oxygenase-1 and biliverdin reductase are affected in brain of PINK1 knockout mice. In addition, posttranslational modifications are a way to control the behavior of proteins, so posttranslational …

The Differences Between Iron And Iron-Substituted Manganese Superoxide Dismutase With Respect To Hydrogen Peroxide Treatment, Jianing Wang

Theses and Dissertations--Chemistry

Iron-substituted manganese superoxide dismutase (Fe(Mn)SOD) was produced using an in vivo preparation method. It’s an inactive enzyme in catalyzing superoxide radical dismutation owing to the mis-incorporation of Fe in the active site evolved to use Mn. To investigate the possible toxicity of human Fe(Mn)SOD proposed by Yamakura, we studied the properties of Fe(Mn)SOD upon H₂O₂ treatment and compared to that of FeSOD. It’s found that the responses to H₂O₂ treatment were different, including the changes of optical spectra, variations of active site coordination and secondary structures. Fe³⁺ reduction was not observed in Fe(Mn)SOD …

Bioc 435: Advanced Topics In Biochemistry—A Peer Review Of Teaching Project Benchmark Portfolio, Edward N. Harris

UNL Faculty Course Portfolios

BIOC 435 or Advanced Topics in Biochemistry is an ACE 10 (Achievement centered education)course for students in their senior year. This is a capstone course for Biochemistry majors and is the last of several biochemistry courses that they will take in their undergraduate enrollment. The course is also open to non-majors in a related science such as Biology and Biological Sciences, although these students typically do not do as well as the majors. Students who take this course should be well-prepared in the basic concepts of biochemistry with regards to nucleic acids and proteins as well as some familiarity with …

High Fat Diet Increased Serum Glutamate Dehydrogenase More Than Chronic Acetaminophen Dosing In Female Mice, Elizabeth Ruth Behmer

All Graduate Theses, Dissertations, and Other Capstone Projects

This laboratory study examined the effects of acetaminophen overdose in normal fed and high-fat fed female mice. Forty female mice were placed on normal and high-fat diets at 4 weeks old. When the mice were significantly different in weight (between 6 and 9 months old), half the mice were dosed with acetaminophen. These mice were daily given an overdose of acetaminophen for 14 days. The dose used was 300 mg/kg mouse (LD50 = 338 mg/kg). The control group was given 10 µl water/g mouse. Levels of serum glutamate dehydrogenase (GDH) were measured to indicate liver damage. GDH is released from …

Catalytic Mechanism And Maturation Of The Metalloenzyme Nitrile Hydratase, Natalie I. Gumataotao

Dissertations

Nitrile hydratases are metalloenzymes that catalyze the hydration of nitriles to their corresponding amides in a specific manner at ambient pressures and temperatures at neutral pH. Traditional industrial methods require high temperature and pressure, extreme pH, and heavy metals. NHases are used as biocatalysts in the large scale industrial production of amide precursors to textiles, animal feedstock, and polymers. Notably, NHase is used in the production of ~100,000 tons of acrylamide annually by the Mitsubishi Corporation.

Despite being used extensively in industry, questions remain about NHase. The catalytic mechanism is not defined. Understanding the way in which the nitrile is …

Numerical Study Of Lipid Translocation Driven By Nanoporation Due To Multiple High-Intensity, Ultrashort Electrical Pulses, Viswanadham Sridhara, Ravindra P. Joshi

Electrical & Computer Engineering Faculty Publications

The dynamical translocation of lipids from one leaflet to another due to membrane permeabilization driven by nanosecond, high-intensity (>100 kV/cm) electrical pulses has been probed. Our simulations show that lipid molecules can translocate by diffusion through water-filled nanopores which form following high voltage application. Our focus is on multiple pulsing, and such simulations are relevant to gauge the time duration over which nanopores might remain open, and facilitate continued lipid translocations and membrane transport. Our results are indicative of a N^1/2 scaling with pulse number for the pore radius. These results bode well for the use of pulse …

Mutations In Phospholamban Alter The Structure And Function Of The Calcium Atpase Regulatory Complex, Neha Abrol

Dissertations

Phospholamban (PLB) is an integral membrane protein that plays an important role in regulation of cardiac calcium handling and contractility. PLB exists as a homopentamer in the membrane, which upon deoligomerization into active monomers reversibly inhibits sarco/endoplasmic reticulum calcium ATPase (SERCA). Mutations in PLB that change the PLB monomer-pentamer equilibrium result in dysregulation of SERCA. To determine the structural and regulatory role of the C-terminal residues of PLB in the membranes of living cells, we fused fluorescent protein tags to PLB and SERCA. We then studied the effect of C-terminal alanine substitutions and truncation mutations on PLB oligomerization and SERCA …

The Dape-Encoded N-Succinyl-L,L-Diaminopimelic Acid Desuccinylase (Dape) From Haemophilus Influenzae As A Prospective Target For The Development Of Novel Antibiotics, Anna Starus

Dissertations

The rapid emergence of bacteria that are resistant to todayfs antibiotics makes them more and more ineffective. Consequently, the need for a novel class of antibacterial agents is rapidly increasing. The importance of this project is emphasized by the emergence of several pathogenic bacterial strains that are resistant to all currently available antibiotics on the market today. One way to approach this problem is to develop drugs that target essential bacterial biosynthetic pathways. Based on bacterial genetic information, the meso]diaminopimelate (mDAP)/lysine biosynthetic pathway offers several potential anti]bacterial targets that have not been yet explored. One of these, the dapE-encoded N-succinyl-L,L-diaminopimelic …

Lineage-Specific Transcriptional Profiles Of Symbiodinium Spp. Unaltered By Heat Stress In A Coral Host, Daniel J. Barshis, Jason T. Ladner, Thomas A. Oliver, Stephen R. Palumbi

Biological Sciences Faculty Publications

Dinoflagellates of the genus Symbiodinium form an endosymbiosis with reef building corals, in which photosynthetically derived nutrients comprise the majority of the coral energy budget. An extraordinary amount of functional and genetic diversity is contained within the coral-associated Symbiodinium, with some phylotypes (i.e., genotypic groupings), conferring enhanced stress tolerance to host corals. Recent advances in DNA sequencing technologies have enabled transcriptome-wide profiling of the stress response of the cnidarian coral host; however, a comprehensive understanding of the molecular response to stress of coral-associated Symbiodinium, as well as differences among physiologically susceptible and tolerant types, remains largely unexplored. Here, …

Atm, Brca1, And Aurora A: Mechanisms Of G2/M Checkpoint Control In Human Embryonic Stem Cells, Jason Beckta

Theses and Dissertations

When cultured in vitro, human embryonic stem cells (hESCs) acquire genetic abnormalities that have slowed their therapeutic use. As hESCs have a “leaky” G1/S boundary, the pressure of ensuring genetic integrity falls on the G2/M checkpoint, which can be activated by failed chromosomal decatenation (among other stimuli). It is hypothesized that hESCs have a deficient decatenation checkpoint, but little data supports this. Evidence suggests that the ataxia telangiectasia mutated (ATM) kinase controls the G2/M decatenation and DNA damage checkpoints, though previous reports are conflicting on this point. My work demonstrates that inhibition of decatenation activates ATM and arrests hESCs in …

The Cytotoxic Effect Of The Bcl-2 Family Of Proteins In Breast Cancer Cells, Yamileth Chin

Theses and Dissertations

Breast cancer is the second leading cause of death amongst women ages 20 to 59. Despite advancements in cancer therapies, more research is necessary to improve the diagnoses and treatment of several types of breast cancer. Paclitaxel (Taxol) is a commonly utilized anti-cancer drug for various types of solid tumors. However, the molecular mechanism utilized by paclitaxel to induce cell death is still elusive. Previous studies in our laboratory have shown that the pro-apoptotic BCL-2 family protein, BAK (BCL-2 homologous antagonist/killer) plays an important role in paclitaxel-induced cell death. In untreated breast cancer cells, BAK is associated with the anti-apoptotic …

Folate Conjugated Dendrimers For Targeted Anticancer Therapy, Shannon Andrews

Theses and Dissertations

Anticancer therapeutics are often limited to suboptimal doses due to their lack of selectivity for tumor cells and resultant damage to healthy tissue. These limitations motivated researchers to develop tumor-specific delivery systems for improved therapeutic efficacy and reduced unintended cytotoxicity. Polyamidoamine dendrimers offer an ideal platform for designing targeted therapeutics with tunable characteristics that optimize pharmacokinetic behavior and targeting specificity. Ligand conjugation to dendrimer provides the biochemical interaction necessary to activate tumor-specific receptors for receptor-mediated endocytosis and effective internalization of polyplexes. Tumor-specific receptors overexpressed in carcinomas, like folate receptor-alpha (FOLRα), are targeted by ligand-conjugated dendrimer to allow enhanced internalization of …

Evaluations Of A Mechanistic Hypothesis For The Influence Of Extracellular Ions On Electroporation Due To High-Intensity, Nanosecond Pulsing, V. Sridhara, R. P. Joshi

Electrical & Computer Engineering Faculty Publications

The effect of ions present in the extracellular medium on electroporation by high-intensity, short-duration pulsing is studied through molecular dynamic simulations. Our simulation results indicate that mobile ions in the medium might play a role in creating stronger local electric fields across membranes that then reinforce and strengthen electroporation. Much faster pore formation is predicted in higher conductivity media. However, the impact of extracellular conductivity on cellular inflows, which depend on transport processes such as electrophoresis, could be different as discussed here. Our simulation results also show that interactions between cations (Na+ in this case) and the carbonyl oxygen of …