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You searched for +publisher:"University of Oklahoma" +contributor:("Li, Jun"). Showing records 1 – 3 of 3 total matches.

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University of Oklahoma

1. Franca, Caio Martinelle. TARGETING PLASMODIUM INVASION PATHWAYS IN MOSQUITOES TO BLOCK MALARIA TRANSMISSION.

Degree: PhD, 2016, University of Oklahoma

Malaria remains a devastating disease. Transmission-blocking vaccines (TBVs) are being considered as a promising approach to eliminate Plasmodium infection. However, the challenges in developing such a vaccine are paramount, since the clinically relevant species of Plasmodium are transmitted by a number of different Anopheles mosquito vectors. Through association studies, we discovered FREP1, a mosquito midgut protein that facilitates P. falciparum parasite transmission. Our biochemical characterization of FREP1 discovered that this protein is secreted as a tetramer, expressed by midgut cells and located in the peritrophic matrix (PM) of mosquito midgut. Molecular analysis revealed that FREP1 anchors parasites to the mosquito PM, assisting ookinetes as a midgut receptor for Plasmodium migration from the blood bolus and subsequent invasion of the midgut epithelium. Since FREP1 is readily accessible to antibodies co-ingested with blood, it is a suitable antigen for targeting by TBV. Sequence comparison of orthologs showed that the fibrinogen-like (FBG) domain of FREP1 is highly conserved (>90% identical) among Anopheles species from different continents, suggesting that anti-FBG antibodies may block malaria transmission to all anopheline mosquitoes. Using standard membrane-feeding assays (SMFA), we showed that anti-FREP1 polyclonal antibodies significantly blocked transmission of P. berghei and P. vivax to An. gambiae and An. dirus respectively. Furthermore, in vivo studies of mice immunized with purified FBG showed that our experimental TBV effectively blocks P. berghei transmission to An. gambiae (>75%), without triggering immunopathology or inducing responses against mouse or human fibrinogens. Anti-FBG serum from the immunized mice also reduces P. falciparum infection of An. gambiae mosquitoes by more than 81% during SMFA, meeting TBV criteria for clinical trials. Finally, I showed that the FBG domain directly interacts with Plasmodium gametocytes and ookinetes, revealing the molecular mechanisms of the transmission-blocking activity of anti-FBG antibodies. FBG also binds to peritrophic matrix, and the N-terminal region of FREP1 keeps FREP1 as tetramers. Collectively, our data support that FREP1-mediated Plasmodium transmission to mosquitoes is a conserved pathway, and that the targeting of the FBG domain of FREP1 will limit the transmission of multiple Plasmodium species to multiple Anopheles species. In summary, I reported here the establishment of a high-level secretion system using mosquito FREP1 signal peptide to secrete recombinant heterologous proteins. I have elucidated FREP1 molecular mechanisms as an ookinete midgut receptor that facilitates parasite invasion of the mosquito midgut, and I have determined that the highly conserved functional FBG domain of FREP1 is a broad-spectrum transmission blocking vaccine antigen. Advisors/Committee Members: Li, Jun (advisor), West, Ann (committee member), Dunn, Anne (committee member), Burgett, Anthony (committee member), Yang, Zhibo (committee member).

Subjects/Keywords: Malaria; Transmission-blocking vaccine; Anopheles; FREP1

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APA (6th Edition):

Franca, C. M. (2016). TARGETING PLASMODIUM INVASION PATHWAYS IN MOSQUITOES TO BLOCK MALARIA TRANSMISSION. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/47016

Chicago Manual of Style (16th Edition):

Franca, Caio Martinelle. “TARGETING PLASMODIUM INVASION PATHWAYS IN MOSQUITOES TO BLOCK MALARIA TRANSMISSION.” 2016. Doctoral Dissertation, University of Oklahoma. Accessed February 26, 2021. http://hdl.handle.net/11244/47016.

MLA Handbook (7th Edition):

Franca, Caio Martinelle. “TARGETING PLASMODIUM INVASION PATHWAYS IN MOSQUITOES TO BLOCK MALARIA TRANSMISSION.” 2016. Web. 26 Feb 2021.

Vancouver:

Franca CM. TARGETING PLASMODIUM INVASION PATHWAYS IN MOSQUITOES TO BLOCK MALARIA TRANSMISSION. [Internet] [Doctoral dissertation]. University of Oklahoma; 2016. [cited 2021 Feb 26]. Available from: http://hdl.handle.net/11244/47016.

Council of Science Editors:

Franca CM. TARGETING PLASMODIUM INVASION PATHWAYS IN MOSQUITOES TO BLOCK MALARIA TRANSMISSION. [Doctoral Dissertation]. University of Oklahoma; 2016. Available from: http://hdl.handle.net/11244/47016


University of Oklahoma

2. Zhang, Genwei. Discovery of the molecular interactions mediating malaria transmission in the mosquito midgut.

Degree: PhD, 2017, University of Oklahoma

Malaria is a worldwide health problem that affects two thirds of the world population and kills approximately one million people annually. Infecting Anopheline mosquitoes is the essential step for malaria transmission. However, the molecular mechanisms of Plasmodium invasion of the mosquito midgut have not been fully elucidated. We identified that the genetic polymorphisms of fibrinogen-related protein 1 (FREP1) gene are significantly associated with Plasmodium falciparum infection in Anopheles gambiae and essential for P. berghei infection in An. gambiae. Moreover, we identified that FREP1 was a tetrameric oligomer and secreted outside of cells. Notably FREP1 bound to the mosquito midgut peritrophic matrix (PM) through direct interaction to Plasmodium ookinetes that invade mosquitoes. Disrupting FREP1 expression by RNAi or blocking endogenous FREP1 by antibodies significantly (p ≤ 0.01) inhibited Plasmodium infection in mosquito midguts. Based on these, we propose that FREP1 mediates Plasmodium invasion of Anopheles midguts. Furthermore, nine P. berghei proteins were identified as candidate FREP1 binding partners (FBP) through pull-down experiments followed by mass spectrometry assays. We cloned these genes and expressed them in insect cells and E. coli. All insect cell-expressed recombinant FBPs interact with FREP1. To test the role of FBPs in malaria transmission, E. coli expressed recombinant proteins were injected into mice to generate polyclonal antibodies. Six FBPs turn out to be strongly immunogenic as evidenced from high specific titers in mouse serum. We will examine activities of these antibodies in inhibiting P. falciparum transmission to An. gambiae in vivo. Besides FREP1-mediated pathway, multiple pathways are hypothesized to involving malaria transmission. Through computational approaches based on protein sequences and gene expression profiles, 95 An. gambiae genes were selected, and 15 of them were cloned and expressed in insect cells. Ten of the recombinant proteins bound to Plasmodium parasites. RNA interference assays confirmed four related to P. falciparum transmission to mosquitoes. Collectively, mosquito midgut FREP1, secreted from the epithelium and functioning as tetramers, mediates Plasmodium invasion via anchoring ookinetes to the mosquito PM and facilitates parasite penetration into the epithelium. Our newly identified mosquito midgut proteins including FREP1 and parasitic binding partners will enable us to limit malaria transmission with novel intervention strategies. Advisors/Committee Members: Li, Jun (advisor), Durica, David (committee member), Bourne, Christina (committee member), West, Ann (committee member), Yang, Zhibo (committee member).

Subjects/Keywords: malaria; mosquito; FREP1

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Zhang, G. (2017). Discovery of the molecular interactions mediating malaria transmission in the mosquito midgut. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/51704

Chicago Manual of Style (16th Edition):

Zhang, Genwei. “Discovery of the molecular interactions mediating malaria transmission in the mosquito midgut.” 2017. Doctoral Dissertation, University of Oklahoma. Accessed February 26, 2021. http://hdl.handle.net/11244/51704.

MLA Handbook (7th Edition):

Zhang, Genwei. “Discovery of the molecular interactions mediating malaria transmission in the mosquito midgut.” 2017. Web. 26 Feb 2021.

Vancouver:

Zhang G. Discovery of the molecular interactions mediating malaria transmission in the mosquito midgut. [Internet] [Doctoral dissertation]. University of Oklahoma; 2017. [cited 2021 Feb 26]. Available from: http://hdl.handle.net/11244/51704.

Council of Science Editors:

Zhang G. Discovery of the molecular interactions mediating malaria transmission in the mosquito midgut. [Doctoral Dissertation]. University of Oklahoma; 2017. Available from: http://hdl.handle.net/11244/51704


University of Oklahoma

3. Wang, Bing. X-RAY CRYSTAL STRUCTURES AND CHARACTERIZATION OF THE PRODUCTS FROM THE INTERACTIONS OF MYOGLOBIN WITH NITROGEN OXIDES AND ARYLHYDRAZINES, AND NITROREDUCTASE INTERACTIONS WITH ORGANIC NITRO COMPOUNDS.

Degree: PhD, 2016, University of Oklahoma

This thesis describes research into the roles that metalloproteins and non-metalloproteins play in the biological inorganic/organic chemistry of common nitrogen oxides. There are three main chapters on this work: the first details the reactions of wild-type and mutant myoglobins (Mbs) in their interactions with nitrite and nitric oxide (NO), the second deals with these Mbs and their formation of bioorganometallic derivatives when reacted with arylhydrazines, and the third deals with an FMN-dependent nitroreductase enzyme and its reactions with the clinically relevant metronidazole drug. Mutations to the distal pocket in the active site of Mb were made; specifically, ferric-aqua derivatives of the mutants were expressed, purified, crystallized, and their crystal structures solved to 1.78-1.85 Å resolution. The proteins crystallized in either the P21 or P6 space groups. The crystals were soaked with nitrite to form their O-bonded MbIII(ONO) complexes whose structures were also solved to 1.57-1.85 Å resolution. In the case of the H64A distal pocket mutant missing the H-bonding amino-acid residue in the 64th position, a water bridge was observed to form linking the protein exterior with the bound nitrite ligand, thus replacing the expected wt H64 H-bonding feature. Further, we noted that the distal pocket Val68 residue adapted its conformation to accommodate the nitrite ligands in some of these complexes. Notably, the O-binding modes observed in the four wt and mutant structures held up exceedingly well even with the variation in H-bonding capacities. These wt and mutant Mb(ONO) compounds can be reduced with sodium dithionite to their respective nitrosyl Mb(NO) products. Verification of the formation of the nitrosyl Fe-NO derivative, and not the closely related nitroxyl Fe-HNO, was provided by FT-infrared spectroscopy. Arylhydrazines and derivatives are prevalent in nature and in pharmaceutical drugs. They interact with various heme proteins resulting in deactivation of the proteins. Eleven X-ray crystal structures of the products from the reactions of wt and mutant (H64A, H64Q, V68A/I107Y) Mbs with arylhydrazines (ArNHNH2; Ar = Ph, m-tol, and p-chlorophenyl) were obtained to 1.70-1.98 Å resolution. Direct Fe-carbon bonds were observed in all these derivatives, establishing that the hydrazine -NHNH2 moieties had been released from the reagents during their reactions with the Fe centers of the Mbs. Importantly, the C-atoms coordinating to the Fe centers were the same as those that bonded to the hydrazine functional groups, implying that the carbon-based radical intermediates were formed in close proximity to the Fe centers allowing for facile and efficient reactions to give the bioorganometallic Mb-aryl products. Significant distal pocket amino acid movements were observed in some cases with the larger p-chlorophenyl ligand aryl; for example, in the H64Q-chlorophenyl derivative, the Gln64 residue swings to a position outside the pocket towards the solvent region. We report the first expression, purification,… Advisors/Committee Members: Richter-Addo, George B. (advisor), West, Ann H. (committee member), Nicholas, Kenneth M. (committee member), Li, Jun (committee member), Ruyle, Jessica (committee member).

Subjects/Keywords: crystallography; myoglobin; nitrite; nitric oxide; nitroreductase; metronidazole

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Wang, B. (2016). X-RAY CRYSTAL STRUCTURES AND CHARACTERIZATION OF THE PRODUCTS FROM THE INTERACTIONS OF MYOGLOBIN WITH NITROGEN OXIDES AND ARYLHYDRAZINES, AND NITROREDUCTASE INTERACTIONS WITH ORGANIC NITRO COMPOUNDS. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/34616

Chicago Manual of Style (16th Edition):

Wang, Bing. “X-RAY CRYSTAL STRUCTURES AND CHARACTERIZATION OF THE PRODUCTS FROM THE INTERACTIONS OF MYOGLOBIN WITH NITROGEN OXIDES AND ARYLHYDRAZINES, AND NITROREDUCTASE INTERACTIONS WITH ORGANIC NITRO COMPOUNDS.” 2016. Doctoral Dissertation, University of Oklahoma. Accessed February 26, 2021. http://hdl.handle.net/11244/34616.

MLA Handbook (7th Edition):

Wang, Bing. “X-RAY CRYSTAL STRUCTURES AND CHARACTERIZATION OF THE PRODUCTS FROM THE INTERACTIONS OF MYOGLOBIN WITH NITROGEN OXIDES AND ARYLHYDRAZINES, AND NITROREDUCTASE INTERACTIONS WITH ORGANIC NITRO COMPOUNDS.” 2016. Web. 26 Feb 2021.

Vancouver:

Wang B. X-RAY CRYSTAL STRUCTURES AND CHARACTERIZATION OF THE PRODUCTS FROM THE INTERACTIONS OF MYOGLOBIN WITH NITROGEN OXIDES AND ARYLHYDRAZINES, AND NITROREDUCTASE INTERACTIONS WITH ORGANIC NITRO COMPOUNDS. [Internet] [Doctoral dissertation]. University of Oklahoma; 2016. [cited 2021 Feb 26]. Available from: http://hdl.handle.net/11244/34616.

Council of Science Editors:

Wang B. X-RAY CRYSTAL STRUCTURES AND CHARACTERIZATION OF THE PRODUCTS FROM THE INTERACTIONS OF MYOGLOBIN WITH NITROGEN OXIDES AND ARYLHYDRAZINES, AND NITROREDUCTASE INTERACTIONS WITH ORGANIC NITRO COMPOUNDS. [Doctoral Dissertation]. University of Oklahoma; 2016. Available from: http://hdl.handle.net/11244/34616

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