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Biochemistry Commons

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Full-Text Articles in Biochemistry

Resistance And Dna Repair Mechanisms Under Nitrosative Stress In Mammalian And Microbial Systems, Hyun-Wook Lee Dec 2010

Resistance And Dna Repair Mechanisms Under Nitrosative Stress In Mammalian And Microbial Systems, Hyun-Wook Lee

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Living organisms are exposed a nitrosative stress mediated by reactive nitrogen species (RNS) that can cause DNA damage and mutation. DNA base deamination is a typical damage occurred under nitrosative stress, which results in conversion of cytosine (C) to uracil (U), adenine (A) to hypoxanthine (I), and guanine (G) to xanthine (X) or oxanine (O). Base excision repair (BER) is an important pathway to remove deaminated DNA lesions in mammalian and microbial systems. My dissertation work concerns with genes and enzymes involved in resistance to nitrosative stress and DNA glycosylases in the BER pathway. In chapter one, I will briefly …


Nitrosative Stress And Dna Repair In Microorganisms, Sung-Hyun Park Dec 2010

Nitrosative Stress And Dna Repair In Microorganisms, Sung-Hyun Park

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DNA can be damaged by reactive nitrogen intermediates (RNI) and reactive oxygen intermediates (ROI) from both endogenous and exogenous sources. Under nitrosative stress conditions, DNA may be modified through base deamination or crosslinking. Uracil (U), xanthine (X) and oxanine (O), hypoxanthine (I), and thymine (T) are the corresponding deamination products derived from cytosine (C), guanine (G), adenine (A), and 5-methylcytosine, respectively. To remove DNA damage, cells are equipped with a variety of DNA repair enzymes which participate in different repair pathways.
My dissertation work involves studies of genes and enzymes in nucleotide excision repair (NER) and base excision repair (BER) …


Understanding Gafp, A Plant Lectin With Broad Spectrum Inhibitory Activity, Alexis Nagel Dec 2010

Understanding Gafp, A Plant Lectin With Broad Spectrum Inhibitory Activity, Alexis Nagel

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South Carolina and Georgia are the largest peach producing regions in the Southeastern United States, generating about $60 million worth (~90,000 tons) of fruit per year on average. Peaches and other stone-fruits (Prunus sp.) can be afflicted by a variety of root-associated diseases which negatively impact annual yield and long-term tree mortality. An engineered Prunus rootstock with enhanced resistance to soil-borne pathogens would therefore be of great benefit to the Southeastern peach industry. The Gastrodia anti-fungal protein (GAFP) is a monocot mannose-binding lectin which is able to inhibit the growth of multiple species of plant pathogenic fungi. Previous findings from …


Investigation Of Biochemistry And Enzymology Of Acyl-Coenzyme A Synthetase, Yu Meng May 2010

Investigation Of Biochemistry And Enzymology Of Acyl-Coenzyme A Synthetase, Yu Meng

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Acetyl-CoA, an essential metabolite at the junction of various anabolic and catabolic pathways, is generated both from the breakdown of carbohydrates, lipids, and amino acids, and from the activation of acetate. AMP-forming acetyl-CoA synthetase, a key enzyme for acetate activation into acetyl-CoA in all domains of life, is a member of the adenylate-forming enzyme superfamily. Although members in the superfamily have different biological functions, they all share the property of forming an acyl-adenylate intermediate. Here I describe my research on characterization of a medium-chain acyl-CoA synthetase from Methanosarcina acetivorans (MacsMa) and identification of key residues in acyl substrate …