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- Diabetes (2)
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Articles 1 - 12 of 12
Full-Text Articles in Physical Sciences and Mathematics
Computational Investigation Of Mononuclear Iron Water Oxidation Catalyst Design, Kristal Stevens, Emily Jarvis
Computational Investigation Of Mononuclear Iron Water Oxidation Catalyst Design, Kristal Stevens, Emily Jarvis
Chemistry and Biochemistry Faculty Works
Hydrogen production from non-carbon sources is an essential component of clean and sustainable technology for reducing greenhouse gas emissions from fuels. Water oxidation, which splits water molecules into hydrogen (protons) and molecular oxygen, is a thermodynamically challenging, multistep reaction achieved in photosynthetic organisms via photocatalysis by the Oxygen Evolving Complex (OEC) of Photosystem II. Mononuclear water oxidation catalysts that aim to mimic nature typically rely on heavy, rare metals such as ruthenium and iridium. Replacing these metals with iron is particularly appealing because it is abundant, benign, and inexpensive. We use density functional theory to characterize the catalytic ability of …
Quantum Chemistry–Machine Learning Approach For Predicting Properties Of Lewis Acid–Lewis Base Adducts, Hieu Huynh, Thomas J. Kelly, Linh Vu, Tung Hoang, Phuc An Nguyen, Tu C. Le, Emily Jarvis, Hung Phan
Quantum Chemistry–Machine Learning Approach For Predicting Properties Of Lewis Acid–Lewis Base Adducts, Hieu Huynh, Thomas J. Kelly, Linh Vu, Tung Hoang, Phuc An Nguyen, Tu C. Le, Emily Jarvis, Hung Phan
Chemistry and Biochemistry Faculty Works
Synthetic design allowing predictive control of charge transfer and other optoelectronic properties of Lewis acid adducts remains elusive. This challenge must be addressed through complementary methods combining experimental with computational insights from first principles. Ab initio calculations for optoelectronic properties can be computationally expensive and less straightforward than those sufficient for simple ground-state properties, especially for adducts of large conjugated molecules and Lewis acids. In this contribution, we show that machine learning (ML) can accurately predict density functional theory (DFT)-calculated charge transfer and even properties associated with excited states of adducts from readily obtained molecular descriptors. Seven ML models, built …
Thermostability And Excision Activity Of Polymorphic Forms Of Hogg1, Kathryn Mouzakis
Thermostability And Excision Activity Of Polymorphic Forms Of Hogg1, Kathryn Mouzakis
Chemistry and Biochemistry Faculty Works
Objectives: Reactive oxygen species (ROS) oxidize guanine residues in DNA to form 7,8-dihydro-oxo-2′-deoxyguanosine (8oxoG) lesions in the genome. Human 8-oxoguanine glycosylase-1 (hOGG1) recognizes and excises this highly mutagenic species when it is base-paired opposite a cytosine. We sought to characterize biochemically several hOGG1 variants that have been found in cancer tissues and cell lines, reasoning that if these variants have reduced repair capabilities, they could lead to an increased chance of mutagenesis and carcinogenesis. Results: We have over-expressed and purified the R46Q, A85S, R154H, and S232T hOGG1 variants and have investigated their repair efficiency and thermostability. The hOGG1 variants showed …
Green Chemistry In United States Science Policy, Emily Jarvis
Green Chemistry In United States Science Policy, Emily Jarvis
Chemistry and Biochemistry Faculty Works
Although optimizing each of the Twelve Principles of Green Chemistry is necessary for achieving the greenest possible chemistry in the lab, there are additional creative ways to promote green chemistry not encompassed by these. Communicating to society the importance of green chemistry beyond the laboratory is essential. Of course, doing this effectively presents distinct challenges to those encountered when designing chemical syntheses. Here, I discuss several observations from my time working in federal science policy as an American Association for the Advancement of Science/American Chemical Society Congressional Science Fellow in the United States Senate. I suggest a practical science policy …
Inhibition Of Toxic Iapp Amyloid By Extracts Of Common Fruits, David A. Moffet, Pei-Yu Kao, Evangeline Green, Catalina Pereirab, Shauna Ekimura, Dennis Juarez, Travis Whyte, Taylor Arhar, Bianca Malaspina, Luiza A. Nogaj
Inhibition Of Toxic Iapp Amyloid By Extracts Of Common Fruits, David A. Moffet, Pei-Yu Kao, Evangeline Green, Catalina Pereirab, Shauna Ekimura, Dennis Juarez, Travis Whyte, Taylor Arhar, Bianca Malaspina, Luiza A. Nogaj
Chemistry and Biochemistry Faculty Works
The aggregation of the 37-amino acid polypeptide islet amyloid polypeptide (IAPP, amylin), as either insoluble amyloid or as small oligomers, appears to play a direct role in the death of pancreatic β-islet cells in type 2 diabetes. It is believed that inhibiting the aggregation of IAPP may slow down, if not prevent entirely, the progression of this disease. Extracts of thirteen different common fruits were analyzed for their ability to prevent the aggregation of amyloidogenic IAPP. Thioflavin T binding, immuno-detection and circular dichroism assays were performed to test the in vitro inhibitory potential of each extract. Atomic force microscopy was …
Dynamic Motions Of The Hiv-1 Frameshift Site Rna, Kathryn Mouzakis
Dynamic Motions Of The Hiv-1 Frameshift Site Rna, Kathryn Mouzakis
Chemistry and Biochemistry Faculty Works
The HIV-1 frameshift site (FS) plays a critical role in viral replication. During translation, the HIV-1 FS transitions from a 3-helix to a 2-helix junction RNA secondary structure. The 2-helix junction structure contains a GGA bulge, and purine-rich bulges are common motifs in RNA secondary structure. Here, we investigate the dynamics of the HIV-1 FS 2-helix junction RNA. Interhelical motions were studied under different ionic conditions using NMR order tensor analysis of residual dipolar couplings. In 150 mM potassium, the RNA adopts a 43°(±4°) interhelical bend angle (β) and displays large amplitude, anisotropic interhelical motions characterized by a 0.52(±0.04) internal …
Global Shape Mimicry Of Trna Within A Viral Internal Ribosome Entry Site Mediates Translational Reading Frame Selection, Kathryn Mouzakis
Global Shape Mimicry Of Trna Within A Viral Internal Ribosome Entry Site Mediates Translational Reading Frame Selection, Kathryn Mouzakis
Chemistry and Biochemistry Faculty Works
The dicistrovirus intergenic region internal ribosome entry site (IRES) adopts a triple-pseudoknotted RNA structure and occupies the core ribosomal E, P, and A sites to directly recruit the ribosome and initiate translation at a non-AUG codon. A subset of dicistrovirus IRESs directs translation in the 0 and +1 frames to produce the viral structural proteins and a +1 overlapping open reading frame called ORFx, respectively. Here we show that specific mutations of two unpaired adenosines located at the core of the threehelical junction of the honey bee dicistrovirus Israeli acute paralysis virus (IAPV) IRES PKI domain can uncouple 0 and …
Structure And Dynamics Of The Hiv-1 Frameshift Element Rna, Kathryn Mouzakis
Structure And Dynamics Of The Hiv-1 Frameshift Element Rna, Kathryn Mouzakis
Chemistry and Biochemistry Faculty Works
The HIV-1 ribosomal frameshift element is highly structured, regulates translation of all virally encoded enzymes, and is a promising therapeutic target. The prior model for this motif contains two helices separated by a three-nucleotide bulge. Modifications to this model were suggested by SHAPE chemical probing of an entire HIV-1 RNA genome. Novel features of the SHAPE-directed model include alternate helical conformations and a larger, more complex structure. These structural elements also support the presence of a secondary frameshift site within the frameshift domain. Here, we use oligonucleotide-directed structure perturbation, probing in the presence of formamide, and in-virion experiments to examine …
Iapp Aggregation And Cellular Toxicity Are Inhibited By 1,2,3,4,6-Penta-O-Galloyl-Β-D-Glucose, Edward Bruno, Catalina Pereira, Karla P. Roman, Marisa Takiguchi, Pei-Yu Kao, Luiza A. Nogaj, David A. Moffet
Iapp Aggregation And Cellular Toxicity Are Inhibited By 1,2,3,4,6-Penta-O-Galloyl-Β-D-Glucose, Edward Bruno, Catalina Pereira, Karla P. Roman, Marisa Takiguchi, Pei-Yu Kao, Luiza A. Nogaj, David A. Moffet
Chemistry and Biochemistry Faculty Works
The polyphenol, 1,2,3,4,6-penta-O-galloyl-β-D-glucose (PGG) has been found to exhibit a host of positive pharmacologic activities, including anti-cancer and anti-diabetic. Little is known about the mode of action of PGG in yielding these positive activities. We show here that PGG is a potent inhibitor of IAPP (islet amyloid polypeptide, amylin) aggregation. Preventing the initial aggregation event of IAPP is one strategy for slowing, and possibly preventing, the toxic effects of IAPP oligomeric intermediates. Equal molar ratios of PGG to IAPP substantially reduced the ability of IAPP to bind thioflavin T. Atomic force microscopy revealed that PGG prevented amyloid-based fiber formation under …
Hiv-1 Frameshift Efficiency Is Primarily Determined By The Stability Of Base Pairs Positioned At The Mrna Entrance Channel Of The Ribosome, Kathryn Mouzakis
Hiv-1 Frameshift Efficiency Is Primarily Determined By The Stability Of Base Pairs Positioned At The Mrna Entrance Channel Of The Ribosome, Kathryn Mouzakis
Chemistry and Biochemistry Faculty Works
The human immunodeficiency virus (HIV) requires a programmed -1 ribosomal frameshift for Pol gene expression. The HIV frameshift site consists of a heptanucleotide slippery sequence (UUUUUUA) followed by a spacer region and a downstream RNA stem-loop structure. Here we investigate the role of the RNA structure in promoting the -1 frameshift. The stem-loop was systematically altered to decouple the contributions of local and overall thermodynamic stability towards frameshift efficiency. No correlation between overall stability and frameshift efficiency is observed. In contrast, there is a strong correlation between frameshift efficiency and the local thermodynamic stability of the first 3-4 bp in …
From Gene Mutation To Protein Characterization, David A. Moffet
From Gene Mutation To Protein Characterization, David A. Moffet
Chemistry and Biochemistry Faculty Works
A seven-week “gene to protein” laboratory sequence is described for an undergraduate biochemistry laboratory course. Student pairs were given the task of introducing a point mutation of their choosing into the well studied protein, enhanced green fluorescent protein (EGFP). After conducting literature searches, each student group chose the mutation they wanted to introduce into EGFP. Students designed their sequence-specific mutagenic primers and constructed their desired mutation. The resulting EGFP mutant proteins were expressed in E. coli, purified and characterized. This laboratory sequence connected the major concepts of molecular biology and biochemistry, while incorporating the thrill of novel discovery in …
Extensive Regional Atmospheric Hydrocarbon Pollution In The Southwestern United States, Lambert A. Doezema
Extensive Regional Atmospheric Hydrocarbon Pollution In The Southwestern United States, Lambert A. Doezema
Chemistry and Biochemistry Faculty Works
Light alkane hydrocarbons are present in major quantities in the near-surface atmosphere of Texas, Oklahoma, and Kansas during both autumn and spring seasons. In spring 2002, maximum mixing ratios of ethane [34 parts per 109 by volume (ppbv)], propane (20 ppbv), and n-butane (13 ppbv) were observed in north-central Texas. The elevated alkane mixing ratios are attributed to emissions from the oil and natural gas industry. Measured alkyl nitrate mixing ratios were comparable to urban smog values, indicating active photochemistry in the presence of nitrogen oxides, and therefore with abundant formation of tropospheric ozone. We estimate that 4-6 teragrams of …