No abstract

Procalcitonin (PCT), a member of the calcitonin (CT) superfamily, is a 116 amino acid, 13 kilodalton precursor protein produced in humans in the parafollicular cells of the thyroid as well as the neuroendocrine cells of the lungs and intestines of healthy individuals. PCT is coded for in the Calc‐I gene, located on chromosome 11. PCT is the precursor to the regulatory protein calcitonin but may have its own, separate role in the human body’s response to bacterial infection. There is a positive correlation between the concentration of PCT in the blood and the severity of a bacterial infection, making PCT an acute phase reactant. Under normal conditions, PCT undergoes proteolytic cleavage in the thyroid and is converted into CT, which then leaves the thyroid and enters the bloodstream; however, under inflammatory conditions, PCT is not cleaved and enters the bloodstream in a three‐section state comprising an amino terminus, immature calcitonin, and calcitonin carboxyl‐terminus peptide. Additionally, under inflammatory conditions, PCT is produced in other locations besides the parafollicular cells of the thyroid and the neuroendocrine cells of the lungs and intestines due to an increase in the expression of the Calc‐I gene. The reason for this increase may be related to potential anti‐inflammatory characteristics of PCT, including an ability to signal a reduction in the production of pro‐inflammatory proteins such as tumor necrosis factor‐alpha and interleukin 1‐beta. Furthermore, PCT in a specific concentration has been shown to reduce the reactivity of lipopolysaccharide (LPS) in gram‐negative bacteria. These properties of PCT have many potential applications in the medical field that are currently being studied or used. For example, detection of PCT in the blood can be used to determine if an infection is viral or bacterial or to evaluate the severity of infection in patients with sepsis. The determination of the pathogen allows for the correct course of appropriate treatment, potentially preventing the overprescription and overuse of antibiotics, a critical concern with the continued rise of bacterial antibiotic resistance. Additionally, as patients recover from a systemic bacterial infection, monitoring the level of PCT allows physicians to determine when the course of antibiotics may be stopped, once again minimizing antibiotic overuse. The Walton High School SMART Team has designed a 3D model of procalcitonin to investigate the relationship between procalcitonin’s structure and its function. Support or Funding Information MSOE Center for Biomolecular Modeling

Tumor necrosis factor‐alpha (TNF‐α) is a 233 amino acid, 17 kilodalton, homotrimer, bell‐shaped proinflammatory cytokine. TNF‐α is usually secreted from monocytes and macrophages and is also an inducer of many proinflammatory cytokines like IL‐1, IL‐6 and others to help regulate immune cell function. . TNF‐α has two transmembrane cell receptors, TNF‐R1 and TNF‐R2, which have functional binding domains located on the outside of the cell and catalytic signaling domains located inside the cell. TNF‐R1 mediates the activation of a number of transcription factors resulting in an increased inflammatory response, while TNF‐R2 increases the number of T‐cells through a proliferation/survival pathway. A high amount of TNF‐α compared to a low number of its receptors leads to joint inflammation and eventual shock, while a low amount of TNF‐α leads to cachexia. Rheumatoid Arthritis (RA) has many causes including environmental factors, proclivity of smoking, or a genetic history, but in all cases, TNF‐α seems to play a role in disease progression due to its high proteins concentration in advanced disease stages. The source of TNF‐α in joints could be due to the production of the protein by CD4+ T cells in the synovial fluid which has been associated with synoviocyte proliferation, osteoclast activation, and cartilage degradation. Attempts to inhibit TNF‐α are currently centered around general suppression of the protein through TNF‐α inhibitors, but due to the devastating effects these treatments have on the immune system, further studies are considering creating higher numbers of anti‐inflammatory cytokines to create a balance between inflammatory and anti‐inflammatory cytokines, while other studies are attempting to target downstream protein targets of TNF‐α in an attempt to selectively suppress disease symptoms. The Walton High School SMART Team has designed a 3D model of TNF‐α using JMOL to investigate the relationship between structure and function.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Asthma is a condition that affects millions. In response to allergens, the smooth muscles surrounding the lungs undergo bronchoconstriction which reduces the amount of air accessible. Bronchoconstriction can be countered by bronchodilation which results from the side effects of Beta‐2 adrenergic receptor (b2AR) antagonists. B2AR is a type of G protein coupled receptors (GPCRs) that bind to a drug like salmeterol and induce a conformational change that activates signal transduction in the cell that results in the relaxation of smooth muscle in the lungs. In 2012, Brian Kobilka and Bob Lefkowitz received a Nobel prize for their biochemical analysis and structural determination of b2AR. Kobilka used the T4 lysozyme to stabilize the protein and create a clearer view of the protein. The critical residues for agonist binding are Phe290, Asp113, Ser207, Ser203, Asn312 and Phe193. The Walton SMART Team (Students Modeling A Research Topic) modeled the b2AR using 3D printing technology demonstrating the interaction profile between the high affinity agonist BI‐167107 that stabilizes the active state of b2AR. Grant Funding Source: Supported by grants from the NIH‐SEPA and NIH‐CTSA.

Carbon dioxide (CO2) is the primary source of carbon for life on Earth. As such, the efficient incorporation of CO2 into organic matter is of significant importance. Ribulose‐1,5 bisphosphate carboxylase/oxygenase (RuBisCO), sequenced from the cyanobacteria Synechococcus PCC6301, is a 64.8 k‐Da photosynthetic enzyme involved in the oxidation‐reduction process of carbon fixation, assimilating inorganic carbon into bioavailable organic carbon. RuBisCO is composed of two subunits: a large L chain and a smaller S chain, with a length of 467 amino acids. Each chain consists of eight sub‐chains and weighs 51.87 k‐Da and 12.93 k‐Da respectively. RuBisCO, the most abundant protein in the world, is slow‐reacting, fixing about 3–10 CO2 molecules each second per molecule of enzyme. During the catalysis of RuBisCO, the formation of an active site intermediate is able to react with either CO2 or Oxygen (O2). Approximately 25% of the time, RuBisCO will bind with O2 instead of CO2. This misbinding has a significant impact on the enzyme's effectiveness within the Calvin cycle as well as other photosynthetic processes. The functionality error of RuBisCO means that the enzyme exhausts large quantities of ATP in order to process the O2 and then attempt to bind to CO2. Minimizing RuBisCO's intermediate active site's availability can reduce the occurrence of photorespiration. While variations to RuBisCO exist between different photosynthetic species, all species experience inefficiencies due to oxygenation to some extent. Efforts to discover more efficient carboxylation through random mutagenesis of RuBisCO lead to the discovery of a mutant that catalyzes the carbon fixation reaction with greater speed, accuracy, and precision. The resultant mutated RuBisCO was chosen through selection in E. coli. Mutations in the C‐terminal loop 6 region and a substitution mutation at 331 of valine to alanine, both within the large subunit, decreased the specificity factor by almost 40%. RuBisCO's enlarged specificity factor could potentially benefit the development and growth of many different species of plants. The potential increase in crop productivity could have a substantial impact on global food distribution. Walton High School SMART Team has designed a 3D model of RuBisCO using JMOL to investigate the relationship between structure and function.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.