Department of Biochemistry and Molecular Biology Saint Louis University, School of Medicine

Time 2020-07-27 14:08:29

Web Name: Department of Biochemistry and Molecular Biology Saint Louis University, School of Medicine

WebSite: http://biochem.slu.edu

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Department of Biochemistry and Molecular BiologyEdward A. Doisy Research CenterSaint Louis University School of Medicine1100 South Grand Blvd.St. Louis, MO 63104Voice: (314) 977-9200Fax: (314) 977-9206Email: biochem@slu.edu EDWARD A. DOISYDepartment of Biochemistry and Molecular BiologySaint Louis University - School of Medicine Find general details on the necessary safety measures required for research staff to return to the laboratory during Phase I of COVID-19 response.A separate, comprehensive site with full details can be accessed here: Resuming ResearchSubmit your required daily health check here: Daily Health Screening Impact of Research in BMB: Dr. Shoemaker's Remarkable Correction of a Misdiagnosis James D. Shoemaker, M.D., Ph.D. (1953-2020), spent his career at Saint Louis University School of Medicine perfecting and implementing the application of gas chromatography/mass spectrometry to the diagnosis of inborn errors of metabolism. He combined a comprehensive grasp of human metabolism with rigorous biochemistry to compile a massive database of metabolic intermediates that were signatures for genetic disorders.When Patti Stallings was convicted and sentenced to life without parole for poisoning her newborn son with antifreeze, William Sly, M.D., alerted Dr. Shoemaker to the case and a possible misdiagnosis. Thanks to Dr. Shoemaker’s careful analysis, he was able to show that toxicology testing had mistaken a metabolic intermediate of the genetic disorder, Methylmalonate Acidemia, for antifreeze. This finding ultimately led to Patti Stalling’s exoneration. The video below depicts this dramatic story, for which Dr. Shoemaker was a hero.Please read Dr. Shoemaker s obituary on the Legacy.com website and on Newslink.The Centennial Chair in Biochemistry:Celebrating 100 Years of Scientific Excellence The Edward A. Doisy Department of Biochemistry Molecular Biology was founded in 1924. Named after its founder, a 1943 Nobel Laureate in Physiology or Medicine and Saint Louis University benefactor, the Edward A. Doisy Department of Biochemistry and Molecular Biology within the Saint Louis University School of Medicine continues a tradition of excellence in research that pushes the frontiers of basic and translational science. Over the past decade, the Department has gained prominence by cultivating talented faculty, garnering numerous accolades, expanding extramural funding by 75%, and publishing impactful work in the field.As an important milestone approaches in 2024, the Department prepares to celebrate 100 years of scientific success that remains unsurpassed among Jesuit academic institutions. Endowing the Centennial Chair in Biochemistry will provide much needed resources to recruit and retain scientific talent, thereby continuing and expanding the upward trajectory of scientific achievement in the Department and at Saint Louis University. 2-Chlorofatty acids are biomarkers of sepsis mortality and mediators of barrier dysfunction in rats 2-Chlorofatty acids are biomarkers of sepsis mortality and mediators of barrier dysfunction in rats Sepsis is defined as the systemic, dysregulated host immune response to an infection that leads to injury to host organ systems and, often, death. Complex interactions between pathogens and their hosts elicit microcirculatory dysfunction. Neutrophil myeloperoxidase (MPO) is critical for combating pathogens, but MPO-derived hypochlorous acid (HOCl) can react with host molecular species as well. Plasmalogens are targeted by HOCl, leading to the production of 2-chlorofatty acids (2-CLFAs). 2-CLFAs are associated with human sepsis mortality, decrease in vitro endothelial barrier function, and activate human neutrophil extracellular trap formation. Here, we sought to examine 2-CLFAs in an in vivo rat sepsis model. Intraperitoneal cecal slurry sepsis with clinically relevant rescue therapies led to ∼73% mortality and evidence of microcirculatory dysfunction. Plasma concentrations of 2-CLFAs assessed 8 h after sepsis induction were lower in rats that survived sepsis than in nonsurvivors. 2-CLFA levels were elevated in kidney, liver, spleen, lung, colon, and ileum in septic animals. In vivo, exogenous 2-CLFA treatments increased kidney permeability, and in in vitro experiments, 2-CLFA also increased epithelial surface expression of vascular cell adhesion molecule 1 and decreased epithelial barrier function. Collectively, these studies support a role of free 2-CLFAs as biomarkers of sepsis mortality, potentially mediated, in part, by 2-CLFA-elicited endothelial and epithelial barrier dysfunction. Protein C is a natural anticoagulant activated by thrombin in a reaction accelerated by the cofactor thrombomodulin. The zymogen to protease conversion of protein C involves removal of a short activation peptide that, relative to the analogous sequence present in other vitamin K-dependent proteins, contains a disproportionately high number of acidic residues. Through a combination of bioinformatic, mutagenesis and kinetic approaches we demonstrate that the peculiar clustering of acidic residues increases the intrinsic disorder propensity of the activation peptide and adversely affects the rate of activation. Charge neutralization of the acidic residues in the activation peptide through Ala mutagenesis results in a mutant activated by thrombin significantly faster than wild type. Importantly, the mutant is also activated effectively by other coagulation factors, suggesting that the acidic cluster serves a protective role against unwanted proteolysis by endogenous proteases. We have also identified an important H-bond between residues T176 and Y226 that is critical to transduce the inhibitory effect of Ca and the stimulatory effect of thrombomodulin on the rate of zymogen activation. These findings offer new insights on the role of the activation peptide in the function of protein C. Juncos JXM, Shakil S, Ahmad A, Aishah D, Morgan CJ, Dell'Italia LJ, Ford DA, Ahmad A and Ahmad S Juncos JXM, Shakil S, Ahmad A, Aishah D, Morgan CJ, Dell'Italia LJ, Ford DA, Ahmad A and Ahmad S The threat from deliberate or accidental exposure to halogen gases is increasing, as is their industrial applications and use as chemical warfare agents. Biomarkers that can identify halogen exposure, diagnose victims of exposure or predict injury severity, and enable appropriate treatment are lacking. We conducted these studies to determine and validate biomarkers of bromine (Br ) toxicity and correlate the symptoms and the extent of cardiopulmonary injuries. Unanesthetized rats were exposed to Br and monitored noninvasively for clinical scores and pulse oximetry. Animals were euthanized and grouped at various time intervals to assess brominated fatty acid (BFA) content in the plasma, lung, and heart using mass spectrometry. Bronchoalveolar lavage fluid (BALF) protein content was used to assess pulmonary injury. Cardiac troponin I (cTnI) was assessed in the plasma to evaluate cardiac injury. The blood, lung, and cardiac tissue BFA content significantly correlated with the clinical scores, tissue oxygenation, heart rate, and cardiopulmonary injury parameters. Total (free + esterified) bromostearic acid levels correlated with lung injury, as indicated by BALF protein content, and free bromostearic acid levels correlated with plasma cTnI levels. Thus, BFAs and cardiac injury biomarkers can identify Br exposure and predict the severity of organ damage. Reactive species generated by heme impair alveolar epithelial sodium channel function in acute respiratory distress syndrome Reactive species generated by heme impair alveolar epithelial sodium channel function in acute respiratory distress syndrome We previously reported that the highly reactive cell-free heme (CFH) is increased in the plasma of patients with chronic lung injury and causes pulmonary edema in animal model of acute respiratory distress syndrome (ARDS) post inhalation of halogen gas. However, the mechanisms by which CFH causes pulmonary edema are unclear. Herein we report for the first time that CFH and chlorinated lipids (formed by the interaction of halogen gas, Cl, with plasmalogens) are increased in the plasma of patients exposed to Cl gas. Ex vivo incubation of red blood cells (RBC) with halogenated lipids caused oxidative damage to RBC cytoskeletal protein spectrin, resulting in hemolysis and release of CFH. Patch clamp and short circuit current measurements revealed that CFH inhibited the activity of amiloride-sensitive epithelial Na channel (ENaC) and cation sodium (Na) channels in mouse alveolar cells and trans-epithelial Na transport across human airway cells with EC of 125 nM and 500 nM, respectively. Molecular modeling identified 22 putative heme-docking sites on ENaC (energy of binding range: 86-1563 kJ/mol) with at least 2 sites within its narrow transmembrane pore, potentially capable of blocking Na transport across the channel. A single intramuscular injection of the heme-scavenging protein, hemopexin (4 μg/kg body weight), one hour post halogen gas exposure, decreased plasma CFH and improved lung ENaC activity in mice. In conclusion, results suggested that CFH mediated inhibition of ENaC activity may be responsible for pulmonary edema post inhalation injury. The J-elongated conformation of β-glycoprotein I predominates in solution: Implications for our understanding of antiphospholipid syndrome Ruben EA, Planer W, Chinnaraj M, Chen Z, Zuo X, Pengo V, De Filippis V, Alluri RK, McCrae KR, Macor P, Tedesco F and Pozzi N The J-elongated conformation of β-glycoprotein I predominates in solution: Implications for our understanding of antiphospholipid syndrome Ruben EA, Planer W, Chinnaraj M, Chen Z, Zuo X, Pengo V, De Filippis V, Alluri RK, McCrae KR, Macor P, Tedesco F and Pozzi N β-glycoprotein I (βGPI) is an abundant plasma protein displaying phospholipid-binding properties. Because it binds phospholipids, it is a target of antiphospholipid antibodies (aPLs) in antiphospholipid syndrome (APS), a life-threatening autoimmune thrombotic disease. Indeed, aPLs prefer membrane-bound βGPI to that in solution. βGPI exists in two almost equally populated redox states: oxidized, in which all the disulfide bonds are formed, and reduced, in which one or more disulfide bonds are broken. Furthermore, βGPI can adopt multiple conformations (i.e. J-elongated, S-twisted, and O-circular). While strong evidence indicates that the J-form is the structure bound to aPLs, which conformation exists and predominates in solution remains controversial, and so is the conformational pathway leading to the bound state. Here, we report that human recombinant βGPI purified under native conditions is oxidized. Moreover, under physiological pH and salt concentrations, this oxidized form adopts a J-elongated, flexible conformation, not circular nor twisted, in which the N-terminal domain I (DI) and the C-terminal domain V (DV) are exposed to the solvent. Consistent with this model, binding kinetics and mutagenesis experiments revealed that in solution the J-form interacts with negatively charged liposomes and with MBB2, a monoclonal anti-DI antibody that recapitulates most of the features of pathogenic aPLs. We conclude that the preferential binding of aPLs to phospholipid-bound βGPI arises from the ability of its pre-existing J-form to accumulate on the membranes, thereby offering an ideal environment for aPL binding. We propose that targeting the J-form of βGPI may provide a strategy to block pathogenic aPLs in APS. Vascular Permeability Disruption Explored in the Proteomes of Mouse Lungs and Human Microvascular Cells following Acute Bromine Exposure Addis DR, Aggarwal S, Doran SF, Jian MY, Ahmad I, Kojima K, Ford DA, Matalon S and Mobley JA Vascular Permeability Disruption Explored in the Proteomes of Mouse Lungs and Human Microvascular Cells following Acute Bromine Exposure Addis DR, Aggarwal S, Doran SF, Jian MY, Ahmad I, Kojima K, Ford DA, Matalon S and Mobley JA Bromine (Br) is an organohalide found in nature and is integral to many manufacturing processes. Br is toxic to living organisms and high concentrations can prove fatal. To meet industrial demand large amounts of purified Br are produced, transported, and stored worldwide providing a multitude of interfaces for potential human exposure through either accidents or terrorism. To identify the key mechanisms associated with acute Br exposure, we havesurveyed the lung proteomes of C57BL/6 male mice and human lung derived microvascular endothelial cells (HMEC's) at 24 hrs following exposure to Br in concentrations likely to be encountered in the vicinity of industrial accidents. Global discovery proteomics applications, combined with systems biology analysis identified robust and highly significant changes in proteins associated with three biological processes: 1. exosome secretion, 2. inflammation, and 3. vascular permeability. We focused on the latter, conducting physiological studies on isolated perfused lungs harvested from mice 24 hrs post Br exposure. These experiments revealed significant increases in the filtration coefficient (Kf) indicating increased permeability of the pulmonary vasculature. Similarly, confluent monolayers of Br and Br-lipid treated HMEC's exhibited differential levels of ZO-1 that found to be dissociated from cell wall localization, an increase in phosphorylation and internalization of E-cadhedrin, as well as increased actin stress fiber formation, all of which are consistent with increased permeability. Taken as a whole, our discovery proteomics and systems analysis workflow, combined with physiological measurements of permeability, revealed both profound and novel biological changes that contribute to our current understanding of Br toxicity. NADPH and Glutathione Redox Link TCA Cycle Activity to Endoplasmic Reticulum Homeostasis Gansemer ER, McCommis KS, Martino M, King-McAlpin AQ, Potthoff MJ, Finck BN, Taylor EB and Rutkowski DT NADPH and Glutathione Redox Link TCA Cycle Activity to Endoplasmic Reticulum Homeostasis Gansemer ER, McCommis KS, Martino M, King-McAlpin AQ, Potthoff MJ, Finck BN, Taylor EB and Rutkowski DT Many metabolic diseases disrupt endoplasmic reticulum (ER) homeostasis, but little is known about how metabolic activity is communicated to the ER. Here, we show in hepatocytes and other metabolically active cells that decreasing the availability of substrate for the tricarboxylic acid (TCA) cycle diminished NADPH production, elevated glutathione oxidation, led to altered oxidative maturation of ER client proteins, and attenuated ER stress. This attenuation was prevented when glutathione oxidation was disfavored. ER stress was also alleviated by inhibiting either TCA-dependent NADPH production or Glutathione Reductase. Conversely, stimulating TCA activity increased NADPH production, glutathione reduction, and ER stress. Validating these findings, deletion of the Mitochondrial Pyruvate Carrier-which is known to decrease TCA cycle activity and protect the liver from steatohepatitis-also diminished NADPH, elevated glutathione oxidation, and alleviated ER stress. Together, our results demonstrate a novel pathway by which mitochondrial metabolic activity is communicated to the ER through the relay of redox metabolites. Endothelial activation and dysfunction are hallmarks of inflammation. Neutrophil-vascular endothelium interactions have significant effects on vascular wall physiology and pathology. Myeloperoxidase (MPO)-derived products released from activated neutrophils can mediate the inflammatory response and contribute to endothelial dysfunction. 2-Chlorofatty aldehyde (2-ClFALD) is the direct oxidation product of MPO-derived hypochlorous acid (HOCl) targeting plasmalogen phospholipids. The role of 2-ClFALD in endothelial dysfunction is poorly understood and may be dependent on the vascular bed. This study compared the role of 2-ClFALD in eliciting endothelial dysfunction in human coronary artery endothelial cells (HCAEC), human lung microvascular endothelial cells (HLMVEC), and human kidney endothelial cells (HKEC). Profound increases in selectin surface expression as well as ICAM-1 and VCAM-1 surface expression were observed in HCAEC and HLMVEC. The surface expression of these adherence molecules resulted in robust adherence of neutrophils and platelets to 2-ClFALD treated endothelial cells. In contrast to HCAEC and HLMVEC, 2-ClFALD-treated HKEC had substantially reduced adherence molecule surface expression with no resulting increase in platelet adherence. 2-ClFALD-treated HKEC did have an increase in neutrophil adherence. All three endothelial cell lines treated with 2-ClFALD displayed a time-dependent loss of barrier function. Further studies revealed 2-ClHDyA localizes to ER and Golgi when using a synthetic alkyne analog of 2-ClFALD in HCAEC and HLMVEC. These findings indicate 2-ClFALDs promote endothelial cell dysfunction with disparate degrees of responsiveness depending on the vascular bed of origin. Quick Links JOB POSTINGS GRADUATE STUDENTS FACULTY RESEARCH SEMINARS EVENTS FACILITIES HISTORY More NewsKyle McCommis Chosen as Editorial FellowCongratulations to Kyle McCommis, Ph.D., who was chosen as an Editorial Board Fellow for the SLU and WU Center for Cellular Imaging CollaborateSLU and Washington University have signed a collaboration agreement involving the WU Center for Cellular Congratulations to Enrico Di CeraCongratulations to Enrico Di Cera, M.D., who was recently elected a Fellow of the American Welcome to New Faculty MemberWelcome to our newest faculty member, Reza Dastvan, Ph.D., who joined the department as an Eissenberg Publishes Elemental HaikusJoel Eissenberg, Ph.D., recently published a book of haikus, "Elements in the uniVerse," that he Ford Presentation Highlighted in CAP TodayDavid Ford's presentation at the 2019 American Association of Clinical Chemistry (AACC) annual meeting was Sverdrup Lab Suppresses Toxic Protein in FSHDFran Sverdrup, Ph.D., and his research group have identified a potential new drug therapy for Faculty Elected as Senior Members of NAICongratulations to Tomasz Heyduk, Ph.D., Professor of Biochemistry, and Yie-Hwa Chang, Ph.D., Associate Professor of New Faculty Member Joins DepartmentWe are pleased to welcome Edwin Antony, Ph.D., to the department as a new faculty David Ford Receives RGF AwardCongratulations to David Ford, Ph.D., Professor of Biochemistry, who received a Research Growth Fund award Department of Biochemistry and Molecular BiologyEdward A. Doisy Research CenterSaint Louis University School of Medicine1100 South Grand Blvd.St. Louis, MO 63104

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