A5075544543- Iron Metabolism and Disorders
- Bacterial Genetics and Biotechnology
- Radioactive element chemistry and processing
- Vibrio bacteria research studies
- Trace Elements in Health
- Antibiotic Resistance in Bacteria
- DNA and Nucleic Acid Chemistry
- Aquaculture disease management and microbiota
- RNA Research and Splicing
- Mass Spectrometry Techniques and Applications
- Biodiesel Production and Applications
- Botanical Research and Chemistry
- RNA and protein synthesis mechanisms
- Electrostatics and Colloid Interactions
- Salmonella and Campylobacter epidemiology
- Erythrocyte Function and Pathophysiology
- Cassava research and cyanide
- Hemoglobinopathies and Related Disorders
- Geochemistry and Elemental Analysis
- Microbial Fuel Cells and Bioremediation
- Legume Nitrogen Fixing Symbiosis
- Catalysis and Hydrodesulfurization Studies
- Radioactive contamination and transfer
- Various Chemistry Research Topics
- RNA modifications and cancer
Stanford University
2015-2018
Lawrence Berkeley National Laboratory
2015-2016
University of California, Berkeley
2012-2015
ConspectusThis Account focuses on the coordination chemistry of microbial iron chelators called siderophores. The initial research (early 1970s) focused simple analogs siderophores, which included hydroxamate, catecholate, or hydroxycarboxylate ligands. subsequent work increasingly transport siderophores and their transport. Since these are pseudo-octahedral complexes often composed bidentate ligands, there is chirality at metal center that in principle independent ligand chirality. It has...
Significance The release of actinides in the environment, particularly after a nuclear power plant accident or potential use radiological dispersal device, is public health threat, as all are radioactive and will trigger damage once internalized by human body. biological chemistry actinide metal ions largely unknown new approaches to understanding pathways underlying contamination needed. This work identifies mammalian pathway for intracellular delivery toxic that actinides, through protein...
Small molecule iron-chelators, siderophores, are very important in facilitating the acquisition of Fe(III), an essential element for pathogenic bacteria. Many Gram-negative outer-membrane transporters and Gram-positive lipoprotein siderophore-binding proteins have been characterized, binding ability Fe-siderophores has determined. However, there is little information regarding these apo-siderophores, iron-free chelators. Here we report that Bacillus cereus YxeB facilitates iron-exchange from...
Siderophores, small iron-binding molecules secreted by many microbial species, capture environmental iron for transport back into the cell. Vibrio cholerae synthesizes and uses catechol siderophore vibriobactin also siderophores other including enterobactin produced Escherichia coli. E. coli secretes both canonical cyclic linear derivatives likely derived from its cleavage esterase Fes. We show here that V. does not use but instead derivatives. lacked a receptor efficient of to promote...
Abstract Iron overload damages many organs. Unfortunately, therapeutic iron chelators also have undesired toxicity and may deliver to microbes. Here we show that a mutant form (K3Cys) of endogenous lipocalin 2 (LCN2) is filtered by the kidney but can bypass sites megalin-dependent recapture, resulting in urinary excretion. Because K3Cys maintains recognition its cognate ligand, siderophore enterochelin, this protein capture transport even acidic conditions urine. Mutant LCN2 strips from...
Iron is an essential element for all organisms, and microorganisms produce small molecule iron-chelators, siderophores, to efficiently acquire Fe(III). Gram-positive bacteria possess lipoprotein siderophore-binding proteins (SBPs) on the membrane. Some of SBPs bind both apo-siderophores (iron-free) Fe-siderophore (iron-chelated) only import Fe-siderophores. When SBP initially binds apo-siderophore, uses siderophore-shuttle mechanism (the exchange Fe(III) from a apo-siderophore bound protein)...
The human protein siderocalin (Scn) inhibits bacterial iron acquisition by binding catechol siderophores. Several pathogenic bacteria respond making stealth siderophores that are not recognized Scn. Fluvibactin and vibriobactin, respectively of Vibrio fluvialis cholerae, include an oxazoline adjacent to a catechol. This chelating unit binds either in catecholate or phenolate-oxazoline coordination mode. latter has been suggested make vibriobactin siderophore without directly identifying the...
Citrate is a common biomolecule that chelates Fe(III). Many bacteria and plants use ferric citrate to fulfill their nutritional requirement for iron. Only the Escherichia coli outer-membrane transport protein FecA has been characterized; little known about other citrate-binding proteins. Here we report unique siderophore-binding from Gram-positive pathogenic bacterium Bacillus cereus binds multinuclear complexes. We have demonstrated B. ATCC 14579 takes up 55 Fe radiolabeled protein, BC_3466...
The high charge density of nucleic acids and resulting ion atmosphere profoundly influence the conformational landscape RNA DNA their association with small molecules proteins. Electrostatic theories have been applied to quantitatively model electrostatic potential surrounding effects atmosphere, but experimental measures tests these models often complicated by changes multisite binding equilibria, among other factors. We sought a simple system further test basic predictions from...