Biochemistry Commons^™

Evolution Of New Enzymatic Function By Structural Modulation Of Cysteine Reactivity In Pseudomonas Fluorescens Isocyanide Hydratase, Mahadevan Lakshminarasimhan, Peter Madzelan, Ruth Nan, Nicole Marie Milkovic, Mark A. Wilson

Department of Biochemistry: Faculty Publications

Isocyanide (formerly isonitrile) hydratase (EC 4.2.1.103) is an enzyme of the DJ-1 superfamily that hydrates isocyanides to yield the corresponding N-formamide. In order to understand the structural basis for isocyanide hydratase (ICH) catalysis, we determined the crystal structures of wild-type and several site-directed mutants of Pseudomonas fluorescens ICH at resolutions ranging from 1.0 to 1.9 Å. We also developed a simple UV-visible spectrophotometric assay for ICH activity using 2-naphthyl isocyanide as a substrate. ICH contains a highly conserved cysteine residue (Cys101) that is required for catalysis and interacts with Asp17, Thr102, and an ordered water molecule in the active …

The Roles Of Rhle And Hfq In Srna-Dependent Gene Regulation, Abeykoon Jayalath Iresha Sandeepanie Rathnayake

Wayne State University Theses

THE ROLES OF RHLE AND HFQ IN SRNA-DEPENDENT GENE REGULATION

by

ABEYKOON JAYALATH IRESHA SANDEEPANIE RATHNAYAKE

DECEMBER 2010

Advisor: Dr. Andrew Feig

Major: Chemistry

Degree: Master of Science

Bacteria are adapted to live in diverse environmental conditions. Thus, they show excellent tolerance and response to extreme environmental conditions caused by low or high temperatures, high salinity, reactive oxygen species or high nutrient concentrations. sRNAs have been identified and characterized as cis-acting or trans-acting post-transcriptional regulators in diverse cellular processes including virulence and adaptation to environmental stress (11,12,14,15). Interactions of sRNAs and target mRNAs result in translational repression, translational activation or/and …

The Alliinase And Lachrymatory Factor Synthase Systems In Petiveria Alliacea, Quan He

Legacy Theses & Dissertations (2009 - 2024)

Isolation and characterization of an alliinase and a lachrymatory factor synthase from the Amazonian medicinal plant Petiveria alliacea is reported. The alliinase is unusual in that it is heteromeric, whereas all previous reports of characterized alliinases have shown them to be monomers or homomultimers. The protein possesses 5 subunits: two alpha subunits which are glycosylated and connected by a disulfide bond, and beta, gamma and delta subunits. The alliinase exhibits broad substrate specificity, reacting with S-substituted-L-cysteine sulfoxides with aromatic, aliphatic, alkenyl and polar side chains. The alliinase-mediated breakdown of a variety of cysteine sulfoxide derivatives yields transitory sulfenic acid intermediate …

Saturation Transfer Difference Nmr Studies : Pyrazinamide And Pyrazinamide Analogs Coordinating With Mycobacterium Tuberculosis Fatty Acid Synthase I (Fas I), Halimah Sayahi

Legacy Theses & Dissertations (2009 - 2024)

One third of the world's population is infected with M. tuberculosis, the causative agent of tuberculosis (TB) that claims the life of approximately 2 million people every year. The rapid spread of multidrug-resistance tuberculosis as well the emergence of extensively drug resistance strains that are resistant to virtually any known antibiotic, has transformed this once curable disease into a major public health challenge. To regain control of this disease and the associated mortality and morbidity new antibiotics are urgently needed.

Elucidating The Structure Of Protein Aggregates By Raman Spectroscopy, Ludmila A. Popova

Legacy Theses & Dissertations (2009 - 2024)

The structures and properties of amyloid fibrils are of considerable interest due to their associations with numerous neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease and transmissible spongiform encephalopaties (prion diseases). Understanding fibrillogenesis at a molecular level requires detailed structural characterization of amyloid fibrils. However amyloid fibrils are difficult objects to study due to their non-crystalline and insoluble nature. These properties make the application of classical tools of structural biology, such as X-Ray crystallography and solution Nuclear Magnetic Resonance spectroscopy, impractical for structural characterization of protein fibrils.

Morphological Changes And Immunohistochemical Expression Of Rage And Its Ligands In The Sciatic Nerve Of Hyperglycemic Pig (Sus Scrofa), Judyta K. Juranek, Alexey Aleshin, Eileen M. Rattigan, Lynne Johnson, Wu Qu, Fei Song, Radha Ananthakrishnan, Nosirudeen Quadri, Shi Du Yan, Ravichandran Ramasamy, Ann Marie Schmidt, Matthew S. Geddis

Publications and Research

The aim of our project was to study the effect of streptozotocin (STZ)—induced hyperglycemia on sciatic nerve morphology, blood plasma markers and immunohistochemical expression of RAGE (the Receptor for Advanced Glycation End-products), and its ligands—S100B and Carboxymethyl Lysine (CML)-advanced glycation endproduct (AGE) in the laboratory pig. Six months after STZ—injections, blood plasma measurements, morphometric analysis of sciatic nerve fiber density, immunofluorescent distribution of potential molecular neuropathy contributors, ELISA measurement of plasma AGE level and HPLC analysis of sciatic nerve levels of one of the pre-AGE and the glycolysis intermediate products—methyl-glyoxal (MG) were performed. The results of our study revealed that …

Stability Of Nucleic Acid Secondary Structures And Their Contribution To Gene Expression, Maged A. Darwish

Seton Hall University Dissertations and Theses (ETDs)

Bacteriorhodopsin (bR) is a highly expressed transmembrane protein that acts as a light-driven proton pump converting light energy into a proton gradient. The extraordinary levels of expression achieved (15-30 mg per liter of culture) are a result of very efficient biogenesis that originates from molecular information encoded in the bacterio-opsin gene {bop) (1). DNA sequence analysis and predictive folding algorithms suggest that the first twenty-five bases of the bop gene mRNA can form a secondary structural element (a "stem-loop"). Using biophysical methods, the goal was to determine if the stem-loop structure exists in solution conditions that mimic the in vivo …

Genetic Connections Between Neurological Disorders And Cholesterol Metabolism, Ingemar Bjorkhem, Valerio Leoni, Steve Meaney

Articles

Cholesterol is an essential component of both the peripheral and central nervous systems of mammals. Over the last decade, evidence has accumulated that disturbances in cholesterol metabolism are associated with the development of various neurological conditions. In addition to genetically defined defects in cholesterol synthesis, which will be covered in another review in this Thematic Series, defects in cholesterol metabolism (cerebrotendinous xanthomatosis) and intracellular transport (Niemann Pick Syndrome) lead to neurological disease. A subform of hereditary spastic paresis (type SPG5) and Huntington's disease are neurological diseases with mutations in genes that are of importance for cholesterol metabolism. Neurodegeneration is generally …

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 …

15N Solid-State Nmr Detection Of Flavin Perturbation By H-Bonding In Models And Enzyme Active Sites, Dongtao Cui

University of Kentucky Doctoral Dissertations

Massey and Hemmerich proposed that the different reactivities displayed by different flavoenzymes could be achieved as a result of dominance of different flavin ring resonance structures in different binding sites. Thus, the FMN cofactor would engage in different reactions when it had different electronic structures. To test this proposal and understand how different protein sites could produce different flavin electronic structures, we are developing solid-state NMR as a means of characterizing the electronic state of the flavin ring, via the ¹⁵N chemical shift tensors of the ring N atoms. These provide information on the frontier orbitals. We propose that …

Amino Acid Transport In Thermophiles: Characterization Of An Arginine-Binding Protein In Thermotoga Maritima, Matthew S. Luchansky, Bryan S. Der, Sabato D'Auria, Gabriella Pocsfalvi, Luisa Iozzion, Daniela Marasco, Jonathan D. Dattelbaum

Chemistry Faculty Publications

Members of the periplasmic binding protein superfamily are involved in the selective passage of ligands through bacterial cell membranes. The hyperthermophilic eubacterium Thermotoga maritima was found to encode a highly stable and specific periplasmic arginine-binding protein (TM0593). Following signal sequence removal and overexpression in Escherichia coli, TM0593 was purified by thermoprecipitation and affinity chromatography. The ultra-stable protein with a monomeric molecular weight of 27.7 kDa was found to exist as both a homodimer and homotrimer at appreciable concentrations even under strongly denaturing conditions, with an estimated transition temperature of 116 °C. Its multimeric structure may provide further evidence of …

Amino Acid Transport In Thermophiles: Characterization Of An Arginine-Binding Protein In Thermotoga Maritima. 2. Molecular Organization And Structural Stability, Andrea Scirè, Anna Marabotti, Maria Staiano, Luisa Iozzion, Matthew S. Luchansky, Bryan S. Der, Jonathan D. Dattelbaum, Fabio Tanfani, Sabato D'Auria

Chemistry Faculty Publications

ABC transport systems provide selective passage of metabolites across cell membranes and typically require the presence of a soluble binding protein with high specificity to a specific ligand. In addition to their primary role in nutrient gathering, the binding proteins associated with bacterial transport systems have been studied for their potential to serve as design scaffolds for the development of fluorescent protein biosensors. In this work, we used Fourier transform infrared spectroscopy and molecular dynamics simulations to investigate the physicochemical properties of a hyperthermophilic binding protein from Thermotoga maritima. We demonstrated preferential binding for the polar amino acid arginine …

Ligand-Protein Interactions Of Inhibitors With Dengue Virus Type 2 Serine Protease : A Structural Study., Rozana Othman

Student Works (2010-2019)

Dengue is a serious infectious disease that is endemic in over 100 countries. There has been an estimate of 50 million infection per year globally, with more than 2.5 billion people are at risk for epidemic transmission. Two principal illnesses associated with dengue are Dengue Fever (DF) and Dengue Haemorrhagic Fever (DHF). To date, there is no licensed vaccine or therapeutic drug available for these illnesses, although there have been reports of some vaccine candidates in clinical trials. Treatments have only been supportive thus far. This thesis describes part of our ongoing effort to search for a lead therapeutic agent …

The Effect Of Heating On The Antioxidants Content In Edible Oil., Premanand Krishnan

Student Works (2010-2019)

There are many types edible oils with various brand found in the market. The types of oils involved in the analysis for the antioxidants content were palm oil, olive oil, canola oil, sunflower oil, soy bean oil, corn oil, gingerly oil, rice bran oil, mixed oil and ayurvedic oil. The method used to evaluate the amount antioxidants in this study was 2, 2-diphenyl-1-picrylhydrazyl (DPPH). In this test, the scavenging of the DPPH radicals was followed by monitoring the decrease in absorbance at 515 nm. Heating the oil samples to various temperatures shows negative effect on the antioxidants content. The antioxidants …

The Thermal Characteristic Of Imipenem Encapsulated In Low And High Molecular Weight Of Polyethylene Glycol., Abdul Aziz Ismail

Student Works (2010-2019)

Microencapsulation technique is widely used in pharmaceutical industries to control the release of a drug. Biodegradable polymer such as Polyethylene glycol (PEG) is frequently used as encapsulation material. This study has tried to produce microencapsulation product of Imipenem antibiotics in Polyethylene Glycol.Commercially available product called Tienam® was used as a major source of Imipenem. We used freeze-drying method to produce the microencapsulation products. The successful of producing of this product is confirmed by the yellowish appearance of the product whereby it shows the colour properties of Tienam® Thermal analysis using Differential Scanning Calorimeter (DSC) was used to characterize pure materials …

Studies Of Antioxidant Activity Of Bioactive Compounds Derived From Ardisia Crispa., Hassan Mahmood Kzar Jindal

Student Works (2010-2019)

In recent times, researches have focused on medicinal plants in order to extract natural and low cost antioxidants that can help protect the human body against oxidative stress, and replace the synthetic additives that might be carcinogenic. In present study, the crude extracts of leaves and fruits from Ardisia crispa were investigated for their chemical constituents and antioxidant activity. Preliminary phytochemical screening of the crude extracts via TLC analysis revealed the presence of several secondary compounds mainly, terpenoids and phenolic compounds in addition to alkaloids and saponins. HPLC analysis showed the possibility of presence of gallic acid in the fruits …

Diversity And Antioxidant Activity Of Trametes Fr. In Malaysia., Noraswati Mohd Nor Rashid

Student Works (2010-2019)

Research on antioxidant properties as a natural antioxidant, particularly in polypores, have been widely done since the past decade. It is known that antioxidant capacity is essential in protecting organisms and cells from damage brought on by oxidative which is believed to be the cause for ageing and degenerative diseases. In this study, biodiversity and antioxidant activity of Malaysian Trametes spp. which is from the group of polypores were investigated. Polypores were collected in Peninsular Malaysia forests from the year 2006 until 2007. The species were identified by taxonomic keys based on macromorphology and micromorphology analysis. Trametes hirsuta, T. pocas, …

In Vitro Cultures For Production Of Zerumbone And Mass Propagation In Zingiber Zerumbet Smith., Farah Diana Idris

Student Works (2010-2019)

Lempoyang (Zingiber zerumbet Smith.) is an important plant which has been propagated because of its medicinal values. Lempoyang is widely used as a folk medicine in Asian countries such as Malaysia, Indonesia, India and Taiwan. Zerumbone, a cyclic sesqueterpene found to be the major and main bioactive compound that gives great potential in medicinal purposes especially in the treatment of chronic diseases based on recent reports. Recently, it was found that zerumbone inhibited the growth of human leukemia cell line, HL-60 cell. Even though there are so many great values contain in the lempoyang but it is hard to obtain …

Identification And Characterization Of Oxalate Oxidoreductase, A Novel Thiamine Pyrophosphate-Dependent 2-Oxoacid Oxidoreductase That Enables Anaerobic Growth On Oxalate, Elizabeth Pierce, Donald F. Becker, Stephen W. Ragsdale

Department of Biochemistry: Faculty Publications

Moorella thermoacetica is an anaerobic acetogen, a class of bacteria that is found in the soil, the animal gastrointestinal tract, and the rumen. This organism engages the Wood-Ljungdahl pathway of anaerobic CO₂ fixation for heterotrophic or autotrophic growth. This paper describes a novel enzyme, oxalate oxidoreductase (OOR), that enables M. thermoacetica to grow on oxalate, which is produced in soil and is a common component of kidney stones. Exposure to oxalate leads to the induction of three proteins that are subunits of OOR, which oxidizes oxalate coupled to the production of two electrons and CO₂ or bicarbonate. Like …

Functional Hybrid Rubisco Enzymes With Plant Small Subunits And Algal Large Subunits Engineered Rbcs Cdna For Expression In Chlamydomonas, Todor Genkov, Moritz Meyer, Howard Griffiths, Robert J. Spreitzer

Department of Biochemistry: Faculty Publications

There has been much interest in the chloroplast-encoded large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) as a target for engineering an increase in net CO₂ fixation in photosynthesis. Improvements in the enzyme would lead to an increase in the production of food, fiber, and renewable energy. Although the large subunit contains the active site, a family of rbcS nuclear genes encodes the Rubisco small subunits, which can also influence the carboxylation catalytic efficiency and CO₂/O₂ specificity of the enzyme. To further define the role of the small subunit in Rubisco function, small subunits from spinach, Arabidopsis, …