Brian M. Hoffman
YOU?
Author Swipe
View article: EPR spectroscopy reveals antioxidant manganese defenses in the Lyme disease pathogen <i>Borrelia burgdorferi</i>
EPR spectroscopy reveals antioxidant manganese defenses in the Lyme disease pathogen <i>Borrelia burgdorferi</i> Open
Oxidative stress defense in aerobic bacteria relies on Mn-superoxide dismutase (MnSOD) and antioxidant Mn-metabolite complexes (H-Mn) to quench superoxide radicals (O 2 •− ). We investigated these antioxidant systems in Borrelia burgdorfer…
View article: In vitro maturation of fully active [FeFe]-hydrogenase in a defined system including the iron carrier NfuA
In vitro maturation of fully active [FeFe]-hydrogenase in a defined system including the iron carrier NfuA Open
The [FeFe]-hydrogenase employs an active-site 6Fe H-cluster to catalyze the reversible reduction of protons to H 2 . A [4Fe-4S] subcluster of the H-cluster is synthesized by housekeeping iron-sulfur cluster assembly machinery, and then ded…
View article: Nitric Oxide restricts iron availability and induces quorum sensing in Streptococcus pyogenes
Nitric Oxide restricts iron availability and induces quorum sensing in Streptococcus pyogenes Open
Nitric oxide (NO) is a free radical signaling molecule with multiple biological functions. As part of the innate immune system, NO has antimicrobial properties playing an important role in host defense. Mechanisms of NO cytotoxicity result…
View article: Spectroscopic Interrogation of Thiolate Hydrogen Bonding in the CO Sensor Protein CooA: Implications for Thiolate Ligation Stability and Cytochrome P450 Function
Spectroscopic Interrogation of Thiolate Hydrogen Bonding in the CO Sensor Protein CooA: Implications for Thiolate Ligation Stability and Cytochrome P450 Function Open
Cysteine (Cys) thiolate coordination in hemoproteins is a unique ligation motif found in enzymes and small molecule sensors. It is posited that divergence between these two functional classes of heme thiolate proteins is a result of distin…
View article: Cryo-EM captures the coordination of asymmetric electron transfer through a di-copper site in DPOR
Cryo-EM captures the coordination of asymmetric electron transfer through a di-copper site in DPOR Open
Enzymes that catalyze long-range electron transfer (ET) reactions often function as higher order complexes that possess two structurally symmetrical halves. The functional advantages for such an architecture remain a mystery. Using cryoele…
View article: Nitric oxide inhibits ten-eleven translocation DNA demethylases to regulate 5mC and 5hmC across the genome
Nitric oxide inhibits ten-eleven translocation DNA demethylases to regulate 5mC and 5hmC across the genome Open
View article: Prophylactically Feeding Manganese to Drosophila Confers Sex-Specific Protection from Acute Ionizing Radiation Independent of MnSOD2 Levels
Prophylactically Feeding Manganese to Drosophila Confers Sex-Specific Protection from Acute Ionizing Radiation Independent of MnSOD2 Levels Open
Ionizing radiation is a health threat to many, including warfighters, radiological emergency responders, radiotherapy patients, and astronauts. Despite this, no FDA-approved prophylactic medical countermeasures exist to attenuate the sympt…
View article: Proton transfer during reduction of the catalytic metallo-cofactors of the three nitrogenase isozymes
Proton transfer during reduction of the catalytic metallo-cofactors of the three nitrogenase isozymes Open
Nitrogenase catalysis involves stepwise addition of 8[e − /H + ]. Electron-transfer has been extensively characterized, but proton delivery has not. We investigate early-stage [e − /H + ] delivery for the three nitrogenase isozymes.
View article: <i>Borrelia burgdorferi</i> radiosensitivity and Mn antioxidant content: antigenic preservation and pathobiology
<i>Borrelia burgdorferi</i> radiosensitivity and Mn antioxidant content: antigenic preservation and pathobiology Open
The bacterium responsible for Lyme disease, Borrelia burgdorferi , accumulates high levels of manganese without iron and possesses a polyploid genome, characteristics suggesting potential extreme resistance to radiation. Contrary to expect…
View article: The ternary complex of Mn <sup>2+</sup> , synthetic decapeptide DP1 (DEHGTAVMLK), and orthophosphate is a superb antioxidant
The ternary complex of Mn <sup>2+</sup> , synthetic decapeptide DP1 (DEHGTAVMLK), and orthophosphate is a superb antioxidant Open
Mn 2+ coordinated by orthophosphate (Pi), metabolites, or peptides acts as a superoxide dismutase (SOD), and these Mn antioxidant complexes are universally accumulated in extremely radiation-resistant cell types across the tree of life. Th…
View article: Discovery of a New Class of Aminoacyl Radical Enzymes Expands Nature’s Known Radical Chemistry
Discovery of a New Class of Aminoacyl Radical Enzymes Expands Nature’s Known Radical Chemistry Open
Radical enzymes, including the evolutionarily ancient glycyl radical enzyme (GRE) family, catalyze chemically challenging reactions that are involved in a myriad of important biological processes. All GREs possess an essential, conserved b…
View article: Correction to “Terminal Hydride Complex of High-Spin Mn”
Correction to “Terminal Hydride Complex of High-Spin Mn” Open
View article: Role of ammonia-lyases in the synthesis of the dithiomethylamine ligand during [FeFe]-hydrogenase maturation
Role of ammonia-lyases in the synthesis of the dithiomethylamine ligand during [FeFe]-hydrogenase maturation Open
View article: Terminal Hydride Complex of High-Spin Mn
Terminal Hydride Complex of High-Spin Mn Open
The iron-molybdenum cofactor of nitrogenase (FeMoco) catalyzes fixation of N2 via Fe hydride intermediates. Our understanding of these species has relied heavily on the characterization of well-defined 3d metal hydride complexes…
View article: Impact of <i>N</i>-Glycosylation on Protein Structure and Dynamics Linked to Enzymatic C–H Activation in the <i>M. oryzae</i> Lipoxygenase
Impact of <i>N</i>-Glycosylation on Protein Structure and Dynamics Linked to Enzymatic C–H Activation in the <i>M. oryzae</i> Lipoxygenase Open
Lipoxygenases (LOXs) from pathogenic fungi are potential therapeutic targets for defense against plant and select human diseases. In contrast to the canonical LOXs in plants and animals, fungal LOXs are unique in having appended N-l…
View article: Nitric oxide inhibits ten-eleven translocation DNA demethylases to regulate 5mC and 5hmC across the genome
Nitric oxide inhibits ten-eleven translocation DNA demethylases to regulate 5mC and 5hmC across the genome Open
DNA methylation at cytosine bases of eukaryotic DNA (5-methylcytosine, 5mC) is a heritable epigenetic mark that can regulate gene expression in health and disease. Enzymes that metabolize 5mC have been well-characterized, yet the discovery…
View article: ENDOR Spectroscopy Reveals the “Free” 5′-Deoxyadenosyl Radical in a Radical SAM Enzyme Active Site Actually is Chaperoned by Close Interaction with the Methionine-Bound [4Fe–4S]<sup>2+</sup> Cluster
ENDOR Spectroscopy Reveals the “Free” 5′-Deoxyadenosyl Radical in a Radical SAM Enzyme Active Site Actually is Chaperoned by Close Interaction with the Methionine-Bound [4Fe–4S]<sup>2+</sup> Cluster Open
1/2H and 13C hyperfine coupling constants to 5'-deoxyadenosyl (5'-dAdo•) radical trapped within the active site of the radical S-adenosyl-l-methionine (SAM) enzyme, pyruvate formate lyase-activating enzyme (PFL…
View article: Pyruvate formate-lyase activating enzyme: The catalytically active 5′-deoxyadenosyl radical caught in the act of H-atom abstraction
Pyruvate formate-lyase activating enzyme: The catalytically active 5′-deoxyadenosyl radical caught in the act of H-atom abstraction Open
Enzymes of the radical S -adenosyl- l -methionine (radical SAM, RS) superfamily, the largest in nature, catalyze remarkably diverse reactions initiated by H-atom abstraction. Glycyl radical enzyme activating enzymes (GRE-AEs) are a growing…
View article: Product analogue binding identifies the copper active site of particulate methane monooxygenase
Product analogue binding identifies the copper active site of particulate methane monooxygenase Open
View article: Nitric oxide inhibits FTO demethylase activity to regulate N6-methyladenosine mRNA methylation
Nitric oxide inhibits FTO demethylase activity to regulate N6-methyladenosine mRNA methylation Open
View article: Computational Description of Alkylated Iron–Sulfur Organometallic Clusters
Computational Description of Alkylated Iron–Sulfur Organometallic Clusters Open
The radical S-adenosyl methionine (SAM) enzyme superfamily has widespread roles in hydrogen atom abstraction reactions of crucial biological importance. In these enzymes, reductive cleavage of SAM bound to a [4Fe-4S]1+ cl…
View article: Characterization of Methyl- and Acetyl-Ni Intermediates in Acetyl CoA Synthase Formed during Anaerobic CO<sub>2</sub> and CO Fixation
Characterization of Methyl- and Acetyl-Ni Intermediates in Acetyl CoA Synthase Formed during Anaerobic CO<sub>2</sub> and CO Fixation Open
The Wood-Ljungdahl Pathway is a unique biological mechanism of carbon dioxide and carbon monoxide fixation proposed to operate through nickel-based organometallic intermediates. The most unusual steps in this metabolic cycle involve a comp…
View article: <sup>13</sup>C Electron Nuclear Double Resonance Spectroscopy-Guided Molecular Dynamics Computations Reveal the Structure of the Enzyme–Substrate Complex of an Active, <i>N</i>-Linked Glycosylated Lipoxygenase
<sup>13</sup>C Electron Nuclear Double Resonance Spectroscopy-Guided Molecular Dynamics Computations Reveal the Structure of the Enzyme–Substrate Complex of an Active, <i>N</i>-Linked Glycosylated Lipoxygenase Open
Lipoxygenase (LOX) enzymes produce important cell-signaling mediators, yet attempts to capture and characterize LOX-substrate complexes by X-ray co-crystallography are commonly unsuccessful, requiring development of alternative structural …
View article: Mechanism of Radical Initiation in the Radical SAM Enzyme Superfamily
Mechanism of Radical Initiation in the Radical SAM Enzyme Superfamily Open
Radical S-adenosylmethionine (SAM) enzymes use a site-differentiated [4Fe-4S] cluster and SAM to initiate radical reactions through liberation of the 5′-deoxyadenosyl (5′-dAdo•) radical. They form the largest enzyme superfamily, with more …
View article: Connecting the geometric and electronic structures of the nitrogenase iron–molybdenum cofactor through site-selective 57Fe labelling
Connecting the geometric and electronic structures of the nitrogenase iron–molybdenum cofactor through site-selective 57Fe labelling Open
View article: Abstract 1343: A Defined Lysate-Free in vitro [FeFe]-Hydrogenase Maturation
Abstract 1343: A Defined Lysate-Free in vitro [FeFe]-Hydrogenase Maturation Open
View article: A conformational equilibrium in the nitrogenase MoFe protein with an α-V70I amino acid substitution illuminates the mechanism of H<sub>2</sub> formation
A conformational equilibrium in the nitrogenase MoFe protein with an α-V70I amino acid substitution illuminates the mechanism of H<sub>2</sub> formation Open
The reactivity of Fe-hydrides at the nitrogenase active-site cofactor is revealed by studies of the α-V70I substituted protein.
View article: <sup>13</sup>C ENDOR Spectroscopy-Guided MD Computations Reveals the Structure of the Enzyme-Substrate Complex of an Active, N-linked Glycosylated Lipoxygenase
<sup>13</sup>C ENDOR Spectroscopy-Guided MD Computations Reveals the Structure of the Enzyme-Substrate Complex of an Active, N-linked Glycosylated Lipoxygenase Open
Lipoxygenases (LOXs) are enzymes responsible for producing important cell signaling mediators and have been extensively studied for their potential clinical relevance as well as to advance our understanding of enzyme catalysis. The common …
View article: Feeding after spawning and energy balance at spawning are associated with repeat spawning interval in steelhead trout
Feeding after spawning and energy balance at spawning are associated with repeat spawning interval in steelhead trout Open
Consecutive and skip repeat spawning (1- or ≥2-year spawning interval) life histories commonly occur in seasonally breeding iteroparous fishes. Spawning interval variation is driven by energetic status and impacts fisheries management. In …
View article: Effects of Desiccation and Freezing on Microbial Ionizing Radiation Survivability: Considerations for Mars Sample Return
Effects of Desiccation and Freezing on Microbial Ionizing Radiation Survivability: Considerations for Mars Sample Return Open
Increasingly, national space agencies are expanding their goals to include Mars exploration with sample return. To better protect Earth and its biosphere from potential extraterrestrial sources of contamination, as set forth in the Outer S…