Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Institution
- Publication Year
- Publication
- Publication Type
Articles 1 - 30 of 40
Full-Text Articles in Biochemistry
Data From: Nek4 Suppresses Cell Proliferation In Bt20 Triple-Negative Breast Cancer Cells By Diminishing Expression Of Cell Cycle Genes, While Its Depletion Mitigates Proliferation In Other Cell Lines, Amanda Ashley
Chemistry & Biochemistry: Datasets
No abstract provided.
Unraveling The Role Of Hid-1: Insights Into Sgii Regulation, Breanna L. Sellers
Unraveling The Role Of Hid-1: Insights Into Sgii Regulation, Breanna L. Sellers
Electronic Theses and Dissertations
The regulated secretory pathway is important for the secretion of hormones and neuropeptides from large dense core vesicles (LDCVs). Dysregulation of the biogenesis of LDCVs can result in metabolic and neurological diseases. Recent studies have suggested that the peripheral membrane protein HID-1 plays a role in the sorting and storage of granins which contribute to LDCV biogenesis. To further understand how HID-1 influences the regulation of granins, we investigated potential HID-1 interactors. We determined that while HID-1 is likely functioning in the same pathway as USP25, a deubiquitinating enzyme (DUB), the cause of reduced cellular SgII levels is likely not …
Dna-Pkcs Rnaseq Data: Dna-Pkcs Wilde-Type Or Kinase-Dead Protein Regulate Basal And Etoposide-Induced Gene Expression Changes, Amanda Ashley
Dna-Pkcs Rnaseq Data: Dna-Pkcs Wilde-Type Or Kinase-Dead Protein Regulate Basal And Etoposide-Induced Gene Expression Changes, Amanda Ashley
Chemistry & Biochemistry: Datasets
No abstract provided.
Polyphenolic Content And Radical Scavenging Activities Of The Peel, Pulp And Seed Of Avocado (Persea Americana Mill.) Grown In Tanzania, Ibrahim Juma, Jan-Eric Englund, Rodomiro Ortiz, Mulatu Geleta, Donatha D. Tibuhwa, Anders S. Carlsson, Agnes Nyomora, Moneim Fatih, Helena Persson Hovmalm
Polyphenolic Content And Radical Scavenging Activities Of The Peel, Pulp And Seed Of Avocado (Persea Americana Mill.) Grown In Tanzania, Ibrahim Juma, Jan-Eric Englund, Rodomiro Ortiz, Mulatu Geleta, Donatha D. Tibuhwa, Anders S. Carlsson, Agnes Nyomora, Moneim Fatih, Helena Persson Hovmalm
Tanzania Journal of Science
Avocado is a healthy fruit and the consumption is continuously growing worldwide. The fruit contains polyphenolic compounds with antioxidant effects. Globally, research has been devoted to exploring the fruit quality, especially compounds with antioxidant effects, from different avocado-growing sites. However, the fruit quality of the Tanzanian avocado has so far not been investigated. In this study, the contents of polyphenols in peel, pulp and seed of avocados sampled in south-western Tanzania are described. The levels of total polyphenolic and flavonoid contents were measured, and antioxidant activity was evaluated using a 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The total polyphenolic content was highest in …
Small Gtpase Regulated Intracellular Protein Trafficking In Endothelium, Caitlin Francis
Small Gtpase Regulated Intracellular Protein Trafficking In Endothelium, Caitlin Francis
Electronic Theses and Dissertations
Intracellular protein trafficking is the movement of membrane-bound organelles to and from requisite locations within the cell. Small GTPases are a critical component to the spatiotemporal accuracy of intracellular trafficking pathways as they determine the specificity and direction of organelle transport. There exists over 150 small GTPases categorized into 5 sub-families and are employed across all cell types. Despite their universal expression and relevance to cellular function, small GTPases remain incompletely understood across tissue types. In various instances, the trafficking pathway of a particular Rab in one cell type may belong to a completely disparate pathway in another cell type. …
Determination Of Sugars, Amino Acids, Ph And Alcohol In Bamboo Beverage From Southern Highlands, Tanzania, Lilian D Kaale
Determination Of Sugars, Amino Acids, Ph And Alcohol In Bamboo Beverage From Southern Highlands, Tanzania, Lilian D Kaale
Tanzania Journal of Science
The amounts of sugars and amino acids play significant roles in defining the fermentation process and quantifying the alcohol levels in beverages, while pH affects the biological stability, colour, oxidation rate, and protein stability of alcoholic beverages. This study investigated the sugar content, amino acids, alcohol levels, and pH of bamboo beverage from Tanzania's southern highlands. During storage, the sugars significantly decreased (p < 0.05), especially when kept at room temperature from 52.96 to 0.00 (source 1), 53.35 to 0.00 (source 2) and 53.57 to 0.00 (source 3) g/L for fructose, from 47.93 to 14.78 (source 1), 47.23 to 14.91 (source 2) and 47.61 to 14.77 (source 3) g/L for glucose, and from 0.40 to 0.00 (source 1), 0.36 to 0.00 (source 2) and 0.37 to 0.00 (source 3) g/L for sucrose after six days of storage. A total of 15 amino acids were determined from the bamboo beverage with tyrosine being the most prevalent (597.68 mg/L for source 1, 599.44 mg/L for source 2 and 597.83 mg/L for source 3), followed by valine (261.13 mg/L for source 1, 261.24 mg/L for source 2 and 262.54 mg/L for source 3), threonine (76.69 mg/L for source 1, 76.91 mg/L for source 2 and 77.13 mg/L for source 3), and serine (66.37 mg/L for source 1, 67.23 mg/L for source 2 and 66.68 mg/L for source 3). After six days of storage at room temperature, there was a significant decrease in pH from 4.04 to 3.63. Alcohol content ranged from 3.11 to 9.05% v/v at the room temperature storage. These results might facilitate the optimal use of bamboo beverages, which have been neglected due to lack of scientific information such as amino acid and sugar levels. Keywords: Bamboo beverage, ulanzi, amino acids, sugars, alcohol content.
Anxiolytic Effects, Antioxidant And Anti-Inflammatory Activities Of The Methanol Extract Of Jatropha Tanjorensis Leaf, Anthony E. Aiwonegbe, Uwaila Omoruyi, Osahon K. Ogbeide, Blessing O. Imoukhuede, Benjamin O. Gabrielsson
Anxiolytic Effects, Antioxidant And Anti-Inflammatory Activities Of The Methanol Extract Of Jatropha Tanjorensis Leaf, Anthony E. Aiwonegbe, Uwaila Omoruyi, Osahon K. Ogbeide, Blessing O. Imoukhuede, Benjamin O. Gabrielsson
Tanzania Journal of Science
The methanol leaf extract of Jatropha tanjorensis was analyzed for its bioactive components, in-vitro antioxidant, antidepressant, anxiolytic and anti-inflammatory activities using established methods. The phytochemicals detected were saponins, tannins, terpenoids, phenolic compounds, alkaloids, flavonoids and eugenols. The total phenolic content (TPC) was 36.48 mgGAE/g, while the total flavonoid content (TFC) was 145.92 mgQE/g of the extract. 1, 1-diphenyl-2-picrylhydrazyl radical scavenging activity gave an IC50 of 185.02 and 5.15 µg/mL for the extract and ascorbic acid (standard), respectively. The 50% lethal dose (LD50) was greater than 5000 mg/kg, while graded doses of 50, 100 and 200 mg/kg of the plant extract …
Foldamers Reveal And Validate Therapeutic Targets Associated With Toxic Α-Synuclein Self-Assembly, Jemil Ahmed, Tessa C. Fitch, Courtney M. Donnelly, Johnson A. Joseph, Tyler D. Ball, Mikaela M. Bassil, Ahyun Son, Chen Zhang, Aurélie Ledreux, Scott Horowitz, Yan Qin, Daniel Paredes, Sunil Kumar
Foldamers Reveal And Validate Therapeutic Targets Associated With Toxic Α-Synuclein Self-Assembly, Jemil Ahmed, Tessa C. Fitch, Courtney M. Donnelly, Johnson A. Joseph, Tyler D. Ball, Mikaela M. Bassil, Ahyun Son, Chen Zhang, Aurélie Ledreux, Scott Horowitz, Yan Qin, Daniel Paredes, Sunil Kumar
Chemistry and Biochemistry: Faculty Scholarship
Parkinson’s disease (PD) is a progressive neurodegenerative disorder for which there is no successful prevention or intervention. The pathological hallmark for PD involves the self-assembly of functional Alpha-Synuclein (αS) into non-functional amyloid structures. One of the potential therapeutic interventions against PD is the effective inhibition of αS aggregation. However, the bottleneck towards achieving this goal is the identification of αS domains/sequences that are essential for aggregation. Using a protein mimetic approach, we have identified αS sequences-based targets that are essential for aggregation and will have significant therapeutic implications. An extensive array of in vitro, ex vivo, and in vivo assays …
Nutritional Composition, Sensory Profile And Consumer Acceptability Of Wheat-Jackfruit Seed Composite Buns, Sarah S Ngwere, Richard J Mongi
Nutritional Composition, Sensory Profile And Consumer Acceptability Of Wheat-Jackfruit Seed Composite Buns, Sarah S Ngwere, Richard J Mongi
Tanzania Journal of Science
Jackfruit seeds flour is very rich in nutrients and may be incorporated into wheat flour to develop nutrient dense baked products. Consumption of these products may improve the nutrition status of the people, hence fulfill sustainable development goal number two. In this study, nutritional composition, sensory profile, and consumer acceptability of wheat-jackfruit seeds composite buns (Mandazi) were investigated. Jackfruit seeds flour (JSF) was developed and incorporated into wheat flour (WF) at 10, 20, and 30% to produce composite flour used for bun preparation. Flours and buns were subjected to proximate, mineral, and sensory analyses with WF serving as a control …
Assessment Of The Quality And Quantity Of Organic Matter In The Rufiji Mangrove Surface Sediments Using Biochemical Composition, Daniel A Shilla
Assessment Of The Quality And Quantity Of Organic Matter In The Rufiji Mangrove Surface Sediments Using Biochemical Composition, Daniel A Shilla
Tanzania Journal of Science
This study was carried out to investigate spatial changes in the quality and quantity of sedimentary organic matter in the Rufiji mangrove system, Tanzania. Sediment samples were collected from three sampling sites. Total organic matter in mangrove sediments ranged from 7.28 ± 2.02% to 10.58 ± 1.34%. Protein concentrations varied from 1,145.33 ± 20.33 μg/g to 2,747.50 ± 25.14 μg/g in the mangrove sediments. Total carbohydrates, lipids and biopolymeric carbon in mangrove sediments ranged between 1,110.50 ± 16.31 μg/g and 1,914.17 ± 27.79 μg/g, 1,436.50 ± 24.13 μg/g and 6,373.50 ± 25.79 μg/g, and 4,496 μg C/g and 10,231.50 μg …
Effects Of Drying, Packaging Conditions And Storage Time On Proximate Composition Of Chia Seeds (Salvia Hispanica), Ashura Katunzi-Kilewela, Leonard Rweyemamu, Oscar Kibazohi, Lilian Kaale
Effects Of Drying, Packaging Conditions And Storage Time On Proximate Composition Of Chia Seeds (Salvia Hispanica), Ashura Katunzi-Kilewela, Leonard Rweyemamu, Oscar Kibazohi, Lilian Kaale
Tanzania Journal of Science
The effects of drying, packaging conditions and storage time on proximate composition of chia seeds were investigated. Chia seeds were dried at 63 °C for 30 min (low-temperature long time–LTLT) and at 75 °C for 30 s (high-temperature short time-HTST) using dry oven, air/vacuum-packed and stored for ten weeks. The effect of heat processing (drying) on chia seeds had significant difference (p < 0.05) in ash, fiber and fat contents while there was no significant difference (p > 0.05) in moisture and protein contents. Except for fiber content, there was no significant difference (p > 0.05) in moisture, ash, fat and protein of chia seeds dried at LTLT and HTST before storage. During storage time, there was …
Validation Of A Deployable Proteomic Assay For The Serological Screening Of Sexual Assault Samples, Catherine O'Sullivan Brown
Validation Of A Deployable Proteomic Assay For The Serological Screening Of Sexual Assault Samples, Catherine O'Sullivan Brown
Electronic Theses and Dissertations
Protein mass spectrometry (MS) has emerged as a technique to supplant traditional serological tests for body fluid identification. It was hypothesized that proteomic techniques would surpass the sensitivity and specificity of traditional serological techniques. An automated workflow coupled with protein MS has been developed for the confirmatory identification of five biological fluids. A developmental validation was completed, assessing parameters such as reproducibility, sensitivity, ion suppression, and limit of detection. Implementation was determined through tandem sample processing by MS, traditional serological tests, and standard DNA profiling methods. The MS approach offered superior detection limits while also providing true confirmatory results, producing …
In Vitro Antioxidant Activities Of Ethanol, Ethyl Acetate And N-Hexane Extracts Of Mangifera Indica Leaves, Yunusa O. Ibrahim, Musa B. Busari, Ruqayyah S. Yusuf, Rabiat U. Hamzah
In Vitro Antioxidant Activities Of Ethanol, Ethyl Acetate And N-Hexane Extracts Of Mangifera Indica Leaves, Yunusa O. Ibrahim, Musa B. Busari, Ruqayyah S. Yusuf, Rabiat U. Hamzah
Tanzania Journal of Science
Mangifera indica leaves have been in use in folk medicine since ancient time, for the treatment and/or management of numerous health complications. In this study, total phenols and flavonoids contents, as well as in vitro antioxidant activities of ethanol, ethyl acetate and n-hexane extracts of M. indica leaves were determined and compared. The in vitro antioxidant activities were determined using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, ferric reducing antioxidant power, and inhibition of lipid peroxidation assays, respectively. The total phenols were found to be present in the descending order of; ethanol extract > ethyl acetate extract > n-hexane extract, while flavonoids were observed …
Acute Toxicity, Antidiarrhoeal And Antioxidant Activities Of Methanolic Leaf Extract Of Baphia Macrocalyx In Mice, Regina Malekela, Jacob Mwakalinga, Rosta Antony, Flora Stephano
Acute Toxicity, Antidiarrhoeal And Antioxidant Activities Of Methanolic Leaf Extract Of Baphia Macrocalyx In Mice, Regina Malekela, Jacob Mwakalinga, Rosta Antony, Flora Stephano
Tanzania Journal of Science
The aim of the current study was to assess the acute toxicity, antidiarrhoeal and antioxidant potentials of methanolic leaf extract of Baphia macrocalyx (BM) in mice. Acute toxicity test of BM extract was performed based on OECD guideline 423. Results revealed that the extract did not produce any changes in general behaviour, body weight or mortality of the tested mice even at the highest oral administered dose (2000 mg/kg body weight). The antidiarrhoeal effect was examined using castor oil induced diarrhoea test. Results showed that BM extract delayed the onset of diarrhoea, decreased frequency of defaecation and reduced the severity …
Comparative In Vitro Antioxidant Activities Of Aqueous Extracts Of Garcinia Kola And Buchholzia Coriacea Seeds, Abdulkadir Abubakar, Moshood Olorunkemi, Musa Busari, Rabiat Hamzah, Tawakaltu Abdulrasheed-Adeleke
Comparative In Vitro Antioxidant Activities Of Aqueous Extracts Of Garcinia Kola And Buchholzia Coriacea Seeds, Abdulkadir Abubakar, Moshood Olorunkemi, Musa Busari, Rabiat Hamzah, Tawakaltu Abdulrasheed-Adeleke
Tanzania Journal of Science
Comparative in vitro antioxidant activities of aqueous extracts of Garcinia kola and Buchholzia coriacea seeds were carried out using 2, 2-diphenyl 1-picrylhydrazyl (DPPH) free radical scavenging activities, ferric reducing antioxidant power (FRAP) and inhibition of lipid peroxidation assays. Total phenolics, alkaloids, tannins, saponins and flavonoids constituents of the samples were also determined. G. kola seeds contained higher concentrations of secondary metabolites compared to B. coriacea seeds except flavonoids. Both G. kola and B. coriacea exhibited minimum percentage inhibition when compared with the gallic acid. However, B. coriacea exhibited significantly (p < 0.05) higher percentage DPPH scarvenging activities (44.66%) when compared with G. kola (43.62%) at maximum concentration of 100 µg/mL. G. kola on the other hand, showed higher percentage inhibition of lipid peroxidation when compared with B. coriacea at all tested concentrations. Percentage FRAP by B. coriacea was significantly (p < 0.05) higher than G. kola at 100 µg/mL (46.65%, and 38.35%, respectively) and 50 µg/mL (38.75%, and 46.05%, respectively), while lower percentage FRAP of the G. kola than B. coriacea were recorded at 25 µg/mL (24.26% and 38.24%, respectively) and 12.5 µg/mL (34.41% and 37.41%, respectively). Therefore, Garcinia kola and B. coriacea showed appreciable antioxidant activities at varying concentrations and this may be due to the presence of various phenolic compounds in both samples Keywords: Buchholzia coriacea; Garcinia kola; Antioxidant; DPPH free radicals; Secondary metabolites.
Quantification Of Mitochondrial Zinc Homeostasis And Analysis Of Zinc And Polyamine-Mediated Axonal Trafficking, Dylan Hunt Fudge
Quantification Of Mitochondrial Zinc Homeostasis And Analysis Of Zinc And Polyamine-Mediated Axonal Trafficking, Dylan Hunt Fudge
Electronic Theses and Dissertations
The zinc ion is an important emerging signaling molecule for biological processes. In this work we engineered improved zinc sensors based on our previously developed fluorescent sensor GZnP1 to provide sensors with a higher fluorescent readout, faster kinetics, and a superior sensitivity to zinc. We utilized these zinc sensors and further developed the sensors to answer questions pertaining to biological zinc. We showed the labile zinc concentration in the mitochondrial matrix was less than 1 pM while the labile zinc concentration in the cytosol and mitochondrial IMS were comparable (~100 pM) across four different cell lines. Using these zinc sensors …
Sorting Of Cargo Proteins Within The Regulated Secretory Pathway: The Peripheral Membrane Protein Hid-1 As A Sorting And Vesicle Biogenesis Factor, Blake H. Hummer
Sorting Of Cargo Proteins Within The Regulated Secretory Pathway: The Peripheral Membrane Protein Hid-1 As A Sorting And Vesicle Biogenesis Factor, Blake H. Hummer
Electronic Theses and Dissertations
Large dense core vesicles (LDCVs) form at the trans-Golgi network (TGN) and mediate the regulated release of neuropeptides and peptide hormones. Despite their central role to physiology, the mechanisms controlling biogenesis and sorting to LDCVs is not well understood. Optimizing the retention using selective hooks (RUSH) method in neuroendocrine cells, we show it is possible to visualize sorting to the constitutive and regulated secretory pathways in real-time and that the bulk of transmembrane LDCV cargoes do not sort directly onto LDCVs, but exit the TGN into non-regulated vesicles to be incorporated to LDCVs at a later step. Additionally, we characterize …
Effects Of Seasons And Zonation On Biochemical Contents Of Two Seagrass Species Along Dar Es Salaam Coast, Tanzania, Wamwi M. Mbaga, Esther F. Mvungi
Effects Of Seasons And Zonation On Biochemical Contents Of Two Seagrass Species Along Dar Es Salaam Coast, Tanzania, Wamwi M. Mbaga, Esther F. Mvungi
Tanzania Journal of Science
Accumulation and allocation of biochemicals in plants are affected by various factors. The influence of seasons and vertical zonation on biochemical contents of seagrasses Cymodocea rotundata and Thalassia hemprichii from Mjimwema seagrass meadow along the coast of Dar es Salaam were assessed. Samples were collected in 2016 during wet/rainy (April–May) and dry (June–July) seasons. Concentrations of crude protein, soluble carbohydrates, phosphorus, lipid, and proline were determined using standard methods. Significant higher levels of phosphorus, lipid, protein and proline were observed during the dry season than in wet season (p < 0.05). Likewise, seagrass population occurring at the shore zone expressed higher levels of biochemical contents than those found at the subtidal zones. The highest concentration of protein was recorded in Thalassia hemprichii (5.8 mg/g dw)), while those of lipid and carbohydrates (27.1 and 53.1 mg/g dw, respectively) were recorded in Cymodocea rotundata. The two species studied did not vary significantly in their biochemical concentrations in both seasons. Generally it was observed that the concentrations of studied biochemicals were up-regulated during the dry season and varied depending on the locations where the seagrass grow. Thus, both season and zonation played roles in biochemical accumulation in the seagrasses understudy, however not interactively.
Amelioration Of Alzheimer's Disease Pathology In 12-Month-Old Happ(Sweind) Transgenic Mice After Treatment With A Cysteine Rich Whey Supplement, Immunocal®, Srivalli Puttagunta
Amelioration Of Alzheimer's Disease Pathology In 12-Month-Old Happ(Sweind) Transgenic Mice After Treatment With A Cysteine Rich Whey Supplement, Immunocal®, Srivalli Puttagunta
Electronic Theses and Dissertations
Deficits in Reelin expression and signaling play a pathogenic role in Alzheimer’s disease (AD). Thus, strategies aimed at correcting Reelin deficits may provide a novel therapeutic approach to treating AD. The cysteine-rich, whey protein supplement, Immunocal®, has recently been shown to rescue Reelin expression in a mouse model of Schizophrenia. Given that Reelin-expressing neurons of the entorhinal cortex region are a highly vulnerable population of cells that are lost early in AD, we examined the effects of Immunocal® in the hippocampal-entorhinal cortex formation in a mouse model of AD. Glutathione levels and Reelin expression in the hippocampal-entorhinal cortex formation (entorhinal …
In Silico Pharmacokinetic And Molecular Docking Studies Of N-Cinnamoyltetraketide Derivatives As Inhibitors Of Cyclooxygenase-2 Enzyme, Stephen S. Nyandoro, Daniel M. Shadrack, Joan J. E. Munissi, Egid B. Mubofu
In Silico Pharmacokinetic And Molecular Docking Studies Of N-Cinnamoyltetraketide Derivatives As Inhibitors Of Cyclooxygenase-2 Enzyme, Stephen S. Nyandoro, Daniel M. Shadrack, Joan J. E. Munissi, Egid B. Mubofu
Tanzania Journal of Science
Recent phytochemical analysis of Toussaintia orientalis leaves yielded series of novel bioactive N-cinnamoyltetraketide derivatives namely toussaintines A-G (t_1 - t_8) some portraying cytotoxicity against the triple negative aggressive human breast cancer cell line (MDA-MB-231) among other potencies. Despite having broad bioactivity spectrum, their general drug-likeness profiles and mode of action (simulated or actual) targeting any enzyme remains uninvestigated. In silico pharmacokinetic, drug-likeness descriptors and molecular docking of the compounds t_1-t_8 targeting inhibition of cyclooxygenase-2 (COX-2) enzyme were evaluated. The Lipinski Rule of Five heralded the pharmacokinetic properties of the studied metabolites. The studied compounds were docked with COX-2 following already …
In Silico Pharmacokinetic And Molecular Docking Studies Of N-Cinnamoyltetraketide Derivatives As Inhibitors Of Cyclooxygenase-2 Enzyme, Stephen S. Nyandoro, Daniel M. Shadrack, Joan J. E. Munissi, Egid B. Mubofu
In Silico Pharmacokinetic And Molecular Docking Studies Of N-Cinnamoyltetraketide Derivatives As Inhibitors Of Cyclooxygenase-2 Enzyme, Stephen S. Nyandoro, Daniel M. Shadrack, Joan J. E. Munissi, Egid B. Mubofu
Tanzania Journal of Science
Recent phytochemical analysis of Toussaintia orientalis leaves yielded series of novel bioactive N-cinnamoyltetraketide derivatives namely toussaintines A-G (t_1 - t_8) some portraying cytotoxicity against the triple negative aggressive human breast cancer cell line (MDA-MB-231) among other potencies. Despite having broad bioactivity spectrum, their general drug-likeness profiles and mode of action (simulated or actual) targeting any enzyme remains uninvestigated. In silico pharmacokinetic, drug-likeness descriptors and molecular docking of the compounds t_1-t_8 targeting inhibition of cyclooxygenase-2 (COX-2) enzyme were evaluated. The Lipinski Rule of Five heralded the pharmacokinetic properties of the studied metabolites. The studied compounds were docked with COX-2 following already …
Evaluating The Interaction Between The Human Melanocortin-2 Receptor And The Accessory Protein, Mrap1: Chimeric Receptor And Alanine Substitution Studies On Transmembrane Domain 4, Extracellular Loop 2, And Transmembrane Domain 5, Perry Victoria Davis
Electronic Theses and Dissertations
The melanocortin-2 receptor (MC2R) is the most complex due to its trafficking and ligand selectivity requirements for proper activation. The MC2R requires the melanocortin receptor accessory protein-1 (MRAP1) for proper trafficking and activation of the receptor by the melanocortin hormone, ACTH. MRAP1 is a single transmembrane-spanning domain protein that creates a homodimer with another MRAP1 protein. Furthermore, MRAP2 creates a heterodimer with the MC2R. Previous studies have shown that the MRAP1 protein contains an activation motif required for activation of MC2R and this activation motif located on the extracellular space side of the plasma membrane of the cell. The objective …
Minireview: Protein Interactions, Jessica Child
Minireview: Protein Interactions, Jessica Child
Honors Theses and Capstones
No abstract provided.
Resonance Assignments And Secondary Structure Predictions Of The As(Iii) Metallochaperone Arsd In Solution, Jun Ye, Yanan He, Jack Skalicky, Barry P. Rosen, Timothy L. Stemmler
Resonance Assignments And Secondary Structure Predictions Of The As(Iii) Metallochaperone Arsd In Solution, Jun Ye, Yanan He, Jack Skalicky, Barry P. Rosen, Timothy L. Stemmler
Biochemistry and Molecular Biology Faculty Publications
ArsD is a metallochaperone that delivers As(III) to the ArsA ATPase, the catalytic subunit of the ArsAB pump encoded by the arsRDABC operon of Escherichia coli plasmid R773. Conserved ArsD cysteine residues (Cys12, Cys13 and Cys18) construct the As(III) binding site of the protein, however a global structural understanding of this arsenic binding remains unclear. We have obtained NMR assignments for ArsD as a starting point for probing structural changes on the protein that occur in response to metalloid binding and upon formation of a complex with ArsA. The predicted solution structure of ArsD is in agreement with recently published …
Frataxin And Mitochondrial Fes Cluster Biogenesis, Timothy L. Stemmler, Emmanuel Lesuisse, Debumar Pain, Andrew Dancis
Frataxin And Mitochondrial Fes Cluster Biogenesis, Timothy L. Stemmler, Emmanuel Lesuisse, Debumar Pain, Andrew Dancis
Biochemistry and Molecular Biology Faculty Publications
Friedreich’s ataxia is an inherited neurodegenerative disease caused by frataxin deficiency. Frataxin is a conserved mitochondrial protein that plays a role in Fe-S cluster assembly in mitochondria. Fe-S clusters are modular cofactors that perform essential functions throughout the cell. They are synthesized by a multi-step and multi-subunit mitochondrial machinery that includes a scaffold protein Isu for assembling a protein bound Fe-S cluster intermediate. Frataxin interacts with Isu, iron, and with the cysteine desulfurase Nfs1 that supplies sulfur, thus placing it at the center of mitochondrial Fe-S cluster biosynthesis.
Oxidation Of Methane By A Biological Dicopper Centre, Ramakrishnan Balasubramanian, Stephen M. Smith, Swati Rawat, Liliya A. Yatsunyk, Timothy L. Stemmler, Amy C. Rosenzweig
Oxidation Of Methane By A Biological Dicopper Centre, Ramakrishnan Balasubramanian, Stephen M. Smith, Swati Rawat, Liliya A. Yatsunyk, Timothy L. Stemmler, Amy C. Rosenzweig
Biochemistry and Molecular Biology Faculty Publications
Vast world reserves of methane gas are underutilized as a feedstock for the production of liquid fuels and chemicals owing to the lack of economical and sustainable strategies for the selective oxidation of methane to methanol1. Current processes to activate the strong C–H bond (104 kcal mol−1) in methane require high temperatures, are costly and inefficient, and produce waste2. In nature, methanotrophic bacteria perform this reaction under ambient conditions using metalloenzymes called methane monooxygenases (MMOs). MMOs thus provide the optimal model for an efficient, environmentally sound catalyst3. There are two types of MMO. Soluble MMO (sMMO),expressed by several strains of …
Nmr Assignments Of A Stable Processing Intermediate Of Human Frataxin, Kalyan C. Kondapalli, Krisztina Z. Bencze, Eric Dizin, James A. Cowan, Timothy L. Stemmler
Nmr Assignments Of A Stable Processing Intermediate Of Human Frataxin, Kalyan C. Kondapalli, Krisztina Z. Bencze, Eric Dizin, James A. Cowan, Timothy L. Stemmler
Biochemistry and Molecular Biology Faculty Publications
Frataxin, a nuclear encoded protein targeted to the mitochondrial matrix, has recently been implicated as an iron chaperone that delivers ferrous iron to the iron-sulfur assembly enzyme IscU. During transport across the mitochondrial membrane, the N-terminal mitochondrial targeting sequence of frataxin is cleaved in a two-step process to produce the mature protein found in the matrix, however N-terminal extended forms of the protein have also been observed in vivo. The recent structural characterization studies of the human frataxin ortholog were performed on a truncated variant of the protein. Here we report the NMR spectral assignment of an extended form of …
Self-Assembly And Disassembly Of The Snare Complex: Examined Using Circular Dichroism And Atomic Force Microscopy, Jeremy D. Cook, Won Jin Cho, Timothy L. Stemmler, Bhanu P. Jena
Self-Assembly And Disassembly Of The Snare Complex: Examined Using Circular Dichroism And Atomic Force Microscopy, Jeremy D. Cook, Won Jin Cho, Timothy L. Stemmler, Bhanu P. Jena
Biochemistry and Molecular Biology Faculty Publications
In this study, we report for the first time that both t-SNAREs and v-SNARE and their complexes in buffered suspension, exhibit defined peaks at CD signals of 208 and 222 nm wavelengths, consistent with a higher degree of helical secondary structure. Surprisingly, when incorporated in lipid membrane, both SNAREs and their complexes exhibit reduced folding. In presence of NSF-ATP, the SNARE complex disassembles, as reflected from the CD signals demonstrating elimination of α-helices within the structure.
Structure And Dynamics Of Metalloproteins In Live Cells, Jeremy D. Cook, James E. Penner-Hahn, Timothy L. Stemmler
Structure And Dynamics Of Metalloproteins In Live Cells, Jeremy D. Cook, James E. Penner-Hahn, Timothy L. Stemmler
Biochemistry and Molecular Biology Faculty Publications
X-ray absorption spectroscopy (XAS) has emerged as one of the premier tools for investigating the structure and dynamic properties of metals in cells and in metal containing biomolecules. Utilizing the high flux and broad energy range of X-rays supplied by synchrotron light sources, one can selectively excite core electronic transitions in each metal. Spectroscopic signals from these electronic transitions can be used to dissect the chemical architecture of metals in cells, in cellular components and in biomolecules at varying degrees of structural resolution. With the development of ever-brighter X-ray sources, X-ray methods have grown into applications that can be utilized …
Involvement Of Methyltransferases Enzymes During The Energy Metabolism Of The Anaerobic Archaeon Methanosarcina Semesiae Sp. Nov., Tj Lyimo
Tanzania Journal of Science
The methyl group transfer from dimethylsulfide (DMS), trimethylamine and methanol to 2-mercaptoethanesulfonic acid (coenzyme M) were investigated from cell extracts of Methanosarcina semesiae sp. nov. to evaluate whether the enzyme systems involved were constitutive or inductive. The extracts from cells grown on DMS exhibited methanogenic activity exclusively with DMS and methanethiol. Likewise when cells were pre-grown on trimethylamine or methanol the extracts only produced methane from the respective metaboilic substrate. Dimethylsulfide:methyl-coenzyme M transferase activity was dependent on ATP, but hydrogen did not stimulate activity. The fact that ATP could be replaced by the reductant Ti(III)-citrate indicates that reductive activation of …