Physical Sciences and Mathematics Commons^™

Luteolin Inhibits Proliferation, Triggers Apoptosis And Modulates Akt/Mtor And Map Kinase Pathways In Hela Cells, Ritu Raina, Sreepoorna Pramodh, Naushad Rais, Shafiul Haque, Jasmin Shafarin, Khuloud Bajbouj, Mawieh Hamad, Arif Hussain

All Works

Flavonoids, a subclass of polyphenols, have been shown to be effective against several types of cancer, by decreasing proliferation and inducing apoptosis. Therefore, the aim of the present study was to assess the anti-carcinogenic potential of luteolin on HeLa human cervical cancer cells, through the use of a cell viability assay, DNA fragmentation assay, mitochondrial membrane potential assay, cell cycle analysis using Annexin/PI staining and flow cytometry, gene expression analysis and a protein profiling array. Luteolin treatment exhibited cytotoxicity towards HeLa cells in a dose- and time-dependent manner, and its anti-proliferative properties were confirmed by accumulation of luteolin-treated cells in …

A Mechanistic Investigation Of Cytochrome C Nitrite Reductase Catalyzed Reduction Of Nitrite To Ammonia: The Search For Catalytic Intermediates, Shahid Shahid

Theses and Dissertations

Cytochrome c Nitrite Reductase (ccNiR) is a periplasmic homodimeric decaheme enzyme that catalyzes the reduction of nitrite to ammonium in a process that involves six electrons and eight protons. Under standard assay conditions, which use a strong reducing agent as an electron source, catalysis takes place rapidly without producing detectable intermediates. However, intermediates do accumulate when weaker reducing agents are employed, allowing the ccNiR mechanism to be studied. Herein, the early stages of Shewanella oneidensis ccNiR-catalyzed nitrite reduction were investigated in isolation by using the weak reducing agents N,N,N’,N’-tetramethyl-p-phenylenediamine (TMPD) and the 2-electron reduced form of indigo trisulfonate. Experiments were …

Effects Of Oxidative Modifications On The Structure And Non-Canonical Functions Of Cytochrome C Studied By Mass Spectrometry, Victor Yin

Electronic Thesis and Dissertation Repository

The peroxidase activity of the mitochondrial protein cytochrome c (cyt c) plays a critical role in triggering programmed cell death, or apoptosis. However, the native structure of cyt c should render this activity impossible due to the lack of open iron coordination sites at its heme cofactor. Despite its key biological importance, the molecular mechanisms underlying this structure-function mismatch remain enigmatic. The work detailed in this dissertation fills this knowledge gap by using mass spectrometry (MS) to decipher the central role that protein oxidative modifications and their associated structural changes play in activating the peroxidase function of cyt c …

Tnf-R1 And Fadd Mediate Uvb-Induced Activation Of K+ Channels In Corneal Epithelial Cells, Peter M. Boersma, Loren D. Haarsma, Mark P. Schotanus, John L. Ubels

University Faculty Publications and Creative Works

The goal of this study was to elucidate the role of Fas, TNF-R1, FADD and cytochrome c in UVB-induced K+ channel activation, an early step in UVB-induced apoptosis, in human corneal limbal epithelial (HCLE) cells. HCLE cells were treated with Fas, TNF-R1 or FADD siRNA and exposed to 80 or 150 mJ/cm2 UVB. K+ channel activation and loss of intracellular K+ were measured using whole-cell patch-clamp recording and ion chromatography, respectively. Cytochrome c was measured with an ELISA kit. Cells in which Fas was knocked down exhibited identical UVB-induced K+ channel activation and loss of intracellular K+ to control cells. …

Liposome-Coated Magnesium Phosphate Nanoparticle For Delivery Of Cytochrome C Into Lung Cancer Cells A549, Weizhou Yue

University of the Pacific Theses and Dissertations

Proteins are large biomolecules that have great therapeutic potential in treating many human diseases. However, chemical/enzymatic degradation, denaturation, and poor penetration into cells are some of the challenges for clinical use of intracellular proteins.

Previously, our group has developed cationic lipid-coated magnesium phosphate nanoparticle (LP MgP NP-CAT) formulations to enhance the intracellular delivery of the negatively charged protein catalase. The goal of the current research is to develop a formulation to deliver cytochrome c (CytC), a positively charged protein into lung cancer cells A549. Specifically, this thesis research prepares and tests liposome-coated magnesium phosphate nanoparticle for delivery of cytochrome c …

Room Temperature Ionic Liquid Templated Meso-Macroporous Material By Self-Assembled Giant Gold Nanoparticles And Its Enhancement On The Direct Electrochemistry Of Cytochrome C, Pei Li, Dong-Ping Zhan, Yuan-Hua Shao

Journal of Electrochemistry

Room temperature ionic liquid (RTIL) is used as a soft-template to organize a meso-macroporous material constructed by self-assembled giant gold nanoparticles which are capped by L-cysteine. First, L-cysteine capped gold nanoparticles can self-assembly to form nanowires and sub-micrometer spherical giant particles due to the static interaction and/or the condensation reaction between the carboxyl and amino groups at the outer terminal of the ligand. Second, the spherical assembled particles can form a quasi-solid gel when grinding with a hydrophobic RTIL, 1-octyl-3-metyllimidazolium hexafluorophosphate. Finally, when the composite gel is coated on a glassy carbon electrode and then polarized by using cyclic voltammetry …

Protein Conformational Studies By Hydrogen/Deuterium Exchange Mass Spectrometry, Antony D. Rodriguez

Electronic Thesis and Dissertation Repository

Proteins are biological macromolecules responsible for the majority of all physiological processes. In order to properly function proteins are required to adopt highly ordered structures. These structural aspects may be found within a single protein or arise from multi-protein complexes. Here hydrogen/deuterium exchange mass spectrometry (HDX-MS) is employed as a tool to determine the extent of protein higher order structure. Exposure to D₂O-based solvent causes the heavier isotope to exchange with amide hydrogens in the polypeptide backbone. This exchange is mainly dependent on protein conformation because the presence of stable hydrogen-bonded secondary structure will impede the incorporation of …

Protein Structure And Interactions Studied By Electrospray Mass Spectrometry, Jiangjiang Liu

Electronic Thesis and Dissertation Repository

Since the emergence of electrospray ionization (ESI) mass spectrometry (MS) as a tool for protein structural studies, this area has experienced tremendous growth. ESI-MS is highly sensitive, and it allows the analysis of biological systems ranging in size from a few atoms to large multi-protein complexes. This work aims to solve questions in protein structural biology by using ESI-MS in conjunction with other techniques.

We initially apply ESI-MS for studying the monomeric protein cytochrome c (Chapter 2). The physical reasons underlying the irreversible thermal denaturation of this protein remain controversial. By utilizing deconvoluted charge state distributions, oxidative modifications were found …

Reaction Enthalpy And Volume Profiles For Excited State Reactions Involving Electron Transfer And Proton-Coupled Electron Transfer, William Antonio Maza

USF Tampa Graduate Theses and Dissertations

Electron transfer, ET, and proton-coupled electron transfer, PCET, reactions are central to biological reactions involving catalysis, energy conversion and energy storage. The movement of electrons and protons in either a sequential or concerted manner are coupled in a series of elementary reaction steps in respiration and photosynthesis to harvest and convert energy consumed in foodstuffs or by absorption of light into high energy chemi-cal bonds in the form of ATP. These electron transfer processes may be modulated by conformational dynamics within the protein matrix or at the protein-protein interface, the energetics of which are still not well understood. Photoacoustic calorimetry …

On The Molecular Mechanism Of Electron Transfer Of Cytochrome C Modulated By Gold Nanoparticles In Nano-Sandwich Architecture, Shou-Rui Lin, Li-Xu Wang, Xiu-E Jiang, Li-Ping Guo

Journal of Electrochemistry

The effects of adsorbed gold nanoparticles on the surface-enhanced infrared absorption (SEIRA) difference spectra of redox-induced cytochrome (Cyt) c in AuNPs/Cyt c/Au sandwich architecture were monitored by SEIRA spectroscopy. The results indicated that the intensity of SEIRA difference spectrum for the vibration of the heme was significantly increased due to the adsorption of gold nanoparticles on the Cyt c. This was induced by the electron transfer between the heme and the gold nanoparticles, which also promoted electron transfer of adsorbed protein. This study suggested a new technique for optimizing the electrochemical property of adsorbed protein.

Temperature Effects On The Electron-Transfer Reactions Of Fe(Cn)63-/4- And Cytochrome C, Jing Tang, Lin Du, Xiao-Jian Xiao, Ning Zhang

Journal of Electrochemistry

Cyclic voltammetric and chronoamperometric techniques were employed to study the temperature effects on the electrochemical reaction of Fe(CN)63-/4- by self-made thermostatic water bath electrochemical cell. The diffusion coefficient D and the formal heterogeneous electron-transfer rate constant k0 were calculated at different temperatures from 25 °C to 75 °C. In the Fe(CN)63-/4- system, the DO values of Fe(CN)63- were directly proportional to temperature, while DR of Fe(CN)64- inversely proportional to temperature. The values of k0 decreased with the increase of temperature due possibly to the electrode passivation resulted from the decomposition of Fe(CN)63-/4- to a Prussian blue like film. Since the …

Intermolecular Electron Transfer Reactivity And Dynamics Of Cytochrome C – Nanoparticle Adducts, Adrienne M. Carver

Open Access Dissertations

Interprotein electron transfer (ET) is crucial for natural energy conversion and a fundamental reaction in the pursuit of understanding the broader problem of proteinprotein interactions and reactivity. Simplifying the complicated nature of these natural systems has driven development of biomimetic approaches. Functionalized gold nanoparticles offer simplified, tunable surfaces that can serve as a proxy to study the reactivity and dynamics of proteins. Amino-acid functionalized gold nanoparticles (Au-TX) served as a complementary partner to cytochrome c (Cyt c) and catalyzed its ET reactivity without altering the native structure. Redox mediator and EPR experiments confirmed that the redox potential and coordination environment …

Investigation Of Fe(Iii) Reduction In Geobacter Sulfurreducens Characterization Of Outer Surface Associated Electron Transfer Components, Xenlei Qian

Open Access Dissertations

Outer membrane cytochromes OmcB and OmcS of Geobacter sulfurreducens are two important components of the respiratory chain for extracellular Fe(III) reduction. OmcS is a loosely bound cell surface protein involved in the reduction of insoluble Fe(III). OmcB is an outer membrane protein and required for insoluble and soluble Fe(III) reduction. The objective of this study was to understand better the mechanism of dissimilatory Fe(III) reduction, focusing on the cell surface proteins by further localization, identification of protein-protein interactions, and biochemical characterization of OmcB and OmcS. OmcB was found to be surface-exposed but embedded in the outer membrane because mild protease …

Fabrication Of Polyvinyl Alcohol Arrays And The Direct Electrochemistry Of Adsorbed Cytochrome C, Yu-Hua Qin, Ruo-Kun Jia, Qing-Juan Wei, Li Ma, Xiao-Hui Guan, Nan Lv

Journal of Electrochemistry

Regular polyvinyl alcohol arrays were prepared with porous polystyrene films by a self-assembly method. Cyt c immobilized on PVA microlens arrays modified glassy carbon electrodes gave a pair of stable,well-defined and quasi-reversible cyclic voltammetric peaks at about 0.072 V (vs. Ag/AgCl) in 0.1 mol/L PBS buffer (pH = 6.89) solution. The effects of scan rate,pH and concentration of buffers on the electrochemical behaviors of Cyt c were studied in detail. The apparent heterogeneous electron transfer rate constant (k0) was evaluated to be 2.98×10-6 cm·s-1.

Physical Properties Of Cytochromes C : 1. Role Of Cytochrome C' As A Nitric Oxide Carrier, 2. Folding Of Cytochrome C, Byunghoon Lee

Legacy Theses & Dissertations (2009 - 2024)

Cytochrome c’ binds and transfers endogenous NO in the denitrifying variant of Rhodobacter sphaeroides 2.4.3 and the NO bound ferrous heme that forms 5-coordinate resembles regulatory site in soluble guanylate cyclase. The Arg127 is close to the 5-coordiate NO bound heme of the cytochrome c’. The mutant (R127A) that was overexpressed in a cytochrome c’ knock-out R. sphaeroides 2.4.3 provided the opportunity to research the functional role of Arg127 in the redox potential and NO binding. The mutant (R127A) showed lower redox potential and lower NO binding free energy than wild type. ERP and ENDOR showed that the mutant had …

Immobilization Of Cytochrome C On The Surface Of Single-Wall Carbon Nanotube And Its Direct Electron Transfer And Electrocatalysis, Ya-Jing Yin, Ya-Fen Lv, Ping Wu, Pan Du, Yan-Mao Shi, Chen-Xin Cai

Journal of Electrochemistry

Cytochrome c(Cyto c) was immobilized on the surface of the single-wall carbon nanotube(SWNT) by using the method of adsorption.Infrared spectroscopy indicated that the Cyto c remained in its original structure and did not undergo structural change after its immobilization on the SWNT.The direct electrochemistry of cyto c,which was adsorbed on the surface of the SWNT,was studied by cyclic voltammetry.The voltammetric results demonstrated that the SWNT had promoting effects on the direct electron transfer of Cyto c and also indicated that the immobilized Cyto c retained its bioelectrocatalytic activity to the reduction of H_(2)O_(2).This modified electrode might be used in development …

The Redox Couple Of The Cytochrome C Cyanide Complex: The Contribution Of Heme Iron Ligation To The Structural Stability, Chemical Reactivity, And Physiological Behavior Of Horse Cytochrome C, Abel Schejter, Michael D. Ryan, Erica R. Blizzard, Chongyao Zhang, Emanuel Margoliash, Benjamin A. Feinberg

Chemistry Faculty Research and Publications

Contrary to most heme proteins, ferrous cytochrome c does not bind ligands such as cyanide and CO. In order to quantify this observation, the redox potential of the ferric/ferrous cytochrome c–cyanide redox couple was determined for the first time by cyclic voltammetry. Its E⁰′ was −240 mV versus SHE, equivalent to −23.2 kJ/mol. The entropy of reaction for the reduction of the cyanide complex was also determined. From a thermodynamic cycle that included this new value for the cyt c cyanide complex E⁰′, the binding constant of cyanide to the reduced protein was estimated to …

Direct Electrochemical Reaction Of Cytochrome C At The Poly (Ethylene Oxide) Film Modified Gold Electrodes, Xiaogang Qu, Gongquan Sun

Journal of Electrochemistry

In this paper, the direct electrochemical reaction of cytochrome c was sudied at the poly (ethylene oxide) film modified gold electrodes. It was found the PEO is a good promoter for the electrochemical reaction of cytochrome c, and the reversibility of reaction of cytochrome c was found to depend on the molecular weight of PEO and the morphology of the PEO films.

Studies Of Electrochemical Behaviors Of Cytochrome C On Pretreated Gold Electrodereceived 16 May, 1996, Jin Luo, Lingling Wu, Shaohua Huang, Zhonghua Lin

Journal of Electrochemistry

The quasi reversible responses of both adsorbed and bulk cytochrome c at the pretreated gold electrode are observed. The adsorption behaviors and reaction kinetics have been studied using in situ FTIR spectroscopy, UV/Vis reflection spectroscopy, voltammetry, AC impedance and potential step methods. The results show that the cytochrome c can irreversibly adsorb on the gold surface in a complete monolayer and the adsorbed layer can mediate the redox reaction of the cytochrome c in the solution in the absence of promoter.

Effects Of Ph,Ligand Cn-,Metallic Ions Hg￣(+2),Cd￣(+2) And Pb￣(2+) On Electroactivity Of Cytochrome C, Jin Luo, Lingling Wu, Jintain Wu, Shaohua Huang, Zhonghua Lin

Journal of Electrochemistry

The effects of pH, ligtlnd CN￣-,metallic ions,Hg￣(+2), Cd￣(+2) and Pb￣(2+) on electroactivity of cytochrome c have been studied with cyclic voltammetry and UV/Vis spectroseopy.In the phosphate buffer solution containing 5 mg/mL cytochrome c, cytochrome c is electroactive at a glod electrode with suitable pretreatment if the pH value is equal to 7.0, but it is electroinactive at the gold electrode if the pH value is equal to 2. 0 or 10.0. The existence of CN- ions in the solution would cause deactivation of cytochrome c in the bulk sulurion, and would not affect the electroactivity of cytochrome c adsorbed on …

The Influnce Of Conjugated Π Bond In Promoter Molecule On The Direct Electrochemical Reaction Of Cytochrome C, Xiaogang Qu, Tianhong Lu, Shaojun Dong

Journal of Electrochemistry

The promoter effect of thiophene with only one-functional group on the directelectrochemical reaction of cytochrome c was compared with that of tetrahydrothiophene in this report.It was found that thiophene is a good promoter.But tetrahydrothiophene could not facilitate the directelectrochemistry of cytochrome c although this compound is very similar to thiophene in str uctureexcept for conjugated π bond.This demonstrated that the conjugated π bond in thiophene plays animportant role for the acceleration of the direct electrochemistry of cytochrome c.

Study On The Electron Transfer Process Of Cytochrome C With Different Charge Transfer Promoters, Guoxin Tang

Journal of Electrochemistry

The diffusion coefficient D. standard rate constant and transfer coefficient afor electron transfer process of cytochrome C at OTTLE in the presence of 4,4'-Dithiedipyridine(PySSPy),Adenine and L-Cysteine were determined by the chronoadsorptometric technique with Au-OTTLE. A computer fitting method was used to calculated these kinetic parameters.The mechanismsof PysSPy,Adenine and L-Cysteine were used as the promoters,and were also discussed.