bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Isotopic Substitution in Enzyme and Co‐factor on Enzyme Catalyzed Hydride Transfer
Authors: Ranasinghe Chethya , Pagano Philip , Guo Qi , Cheatum Christopher , Kohen Amnon 
Published: June 2021

Enzyme dynamics range from seconds to femtoseconds. Previous computational, theoretical, and experimental studies have shown an imperative role of slow enzyme dynamics in its function. It is equally important to unravel the origin of fast enzyme dynamics, which are more likely to play a role in catalyzing chemical bond cleavage. Isotopically labeled (heavy) enzymes and subsequently heavy cofactors were employed to experimentally study the role of fast dynamics. Here, we used nicotinamide adenine dinucleotide (NAD+) dependent formate dehydrogenase (FDH, EC 1.2.1.2) as the model system. Heavy enzyme studies were carried out with 13C; 15N and 13C; 15N; 2H labeled FDHs. Temperature dependence of kinetic isotope effects (KIE) were compared between light and heavy FDHs. The results showed that perturbation of fast enzyme dynamics by mass modulation, alters the chemical step at the tunneling ready state (TRS, a diffused transition state) of the catalyzed hydride transfer. Studies are underway to examine similar trend using heavy cofactor (NAD+). Temperature dependence of KIE would give insight to the extent of contribution of the ring motions in sampling the donor‐acceptor distances at the TRS.In addition to the kinetic measurements, vibrational spectroscopy will be used to test the effect of heavy protein and cofactor on dynamics at the enzyme's transition state. Azide ion, which is a transition state analog of the FDH catalyzed reaction, is a good IR chromophore. This enables the use of vibrational spectroscopic methods such as two dimensional IR (2D‐IR), to directly probe the femtosecond‐picosecond timescale motions in the enzyme active site. Together, these studies should shed light on the molecular origin of fast motions that enhance catalytic efficiency of enzymes.Support or Funding InformationNIH GM065368 and GM79368, NSF CHE‐1149023, BSF 2012340
Young adults physical activity behavior and chronic disease prevention knowledge across Appalachia
Authors: Barr Makenzie L , Beller Erika L , Colby Sarah E , Morrell Jesse , Kidd Tandalayo , Riggsbee Kristin , Olfert Melissa Diann 
Published: June 2021

Chronic disease refers to a host of diseases ranging from pulmonary diseases to cardiovascular diseases, obesity, diabetes, metabolic disorders, and cancer. Within the United States population, the Appalachian region (New York, Ohio, Pennsylvania, West Virginia, Kentucky, South Carolina, North Carolina, Georgia, Mississippi, and Alabama) has some of the highest incidence rates within the country. Conditions such as these are on the rise, and intervening is critical. Specifically, the knowledge of chronic disease prevention is important to understand early in the life span to decrease incidence in older adulthood. Additionally, previous research has shown that physical activity is a primary preventative action for chronic disease. In a sample of 18–24 year olds from eight different universities, which are predominately Caucasian (55%), non‐Appalachian (83.7%, Appalachian N=949, non‐Appalachian N=132), and female (66%), chronic disease prevention knowledge (CDK) and physical activity (PA) were summarized to identify the differences in scores across Appalachian status. CDK was broken into two categories: knowledge of fat and fiber in foods as it related to prevention and knowledge and beliefs of diet and cancer risk. These categories were scored on a scale of 1=low knowledge, 2=moderate knowledge, and 3=high knowledge. PA was scored from the International Physical Activity Questionnaire (IPAQ) of 1=not active, 2=moderately active, and 3=very active. Participants who reported as identifying as Appalachian status had their highest proportion of individuals in the low knowledge level for fat and fiber knowledge (52.5%) and moderate level for diet and cancer knowledge (54.1%). For PA, Appalachian status individuals had their highest proportion in the ‘very active’ category (52.8%). Likewise, in the non‐Appalachian group, individuals were also highest proportion in the low knowledge level for fat and fiber knowledge (54.5%), and moderate level for diet and cancer knowledge (57.9%). Further, in IPAQ category, they were also in the ‘very active’ category (50.7%). For the current results, across both Appalachian and non‐Appalachian status, young adults from the eight universities are reported as being very active but have low knowledge of fat and fiber in foods for a prevention measure and moderate knowledge and beliefs of how diet impacts cancer risk. Further exploration is needed in the education of young adults on prevention of diet and chronic diseases.Support or Funding InformationApproval to use the data set was granted by the University of Tennessee Institutional Review Board prior to study implementation. This material is based upon work that is supported by the National Institute of Food and Agriculture, U.S. Department of Agriculture, under award number 2014‐67001‐21851.
INDIVIDUAL VARIABILITY IN SYMPATHETIC NEURAL RESPONSES TO ALTITUDE EXPOSURE: RELATIONSHIP TO SEA LEVEL SYMPATHETIC NERVE ACTIVITY
Authors: Mitchell Katherine , Bradbury Karleigh , Beidleman Beth A. , Fulco Charles S. , Muza Stephen , Posch Alexander , Charkoudian Nisha 
Published: June 2021

Acute or chronic altitudeexposure causes increased sympathetic nerve activity (SNA), which may persist after the exposure ends. However, it is unknown if an individual's level oftonic SNA at sea level (SL, 50 m) is associated with the change in SNA after chronic altitude exposure.PURPOSETo evaluate muscle SNA (MSNA) at SL before and after 12 days of altitude residence at the summit of Pikes Peak, CO (PP, 4300 m). We hypothesized that: (1) the altitude exposure would result in increased MSNA which would persist into the first 24 hours after return to SL; and (2) the magnitude of individual increases in MSNA after exposure would be inversely related to their SL baseline levels of MSNA.METHODSSupine MSNA (via peroneal microneurography), heart rate (HR), and blood pressure (BP) were measured pre‐ and post‐residing on the summit of PP for 12 days in 9healthy humans (7 M, 2 F; 24 ± 8 years). Paired t‐tests were used to compare pre‐ and post‐altitude responses.RESULTSMSNA was higher within 24 hours of return from altitude (27 ± 5 bursts/min; 51± 10 bursts/100 heart beats [hb]) vs. SL (17 ± 6 bursts/min; 33 ± 14 bursts/100hb)(p < 0.01 for both). Individuals with higher SL baseline MSNA had smaller increases in MSNA after altitude exposure than those with lower SL MSNA (r = − 0.69,p < 0.05). Altitude exposure resulted in no significant differences in HR or BP (p > 0.05 for both).CONCLUSIONAfter 12 days of altitude residence, (1) MSNA levels remain elevated during the first 24 hrs after return to SL, and (2) there is individual variability in the magnitude of the MSNA increase that is inversely related to SL baseline MSNA. Funded by USAMRMC; author views not official US Army or DOD policy.Support or Funding InformationFunded by USAMRMC
Expression, purification, and characterization of an intrinsically disordered Late Embryogenesis Abundant (LEA) protein from Artemia franciscana utilizing Escherichia coli and Nicotiana tabacum
Authors: Karim Md Fazlul , Yordanov Yordan S. , Menze Michael A. 
Published: June 2021

Anhydrobiosis is an astounding strategy that allows certain species (both in animals and plants) to survive severe environmental conditions such as desiccation, extreme cold, or heat in the habitat. Among different molecular strategies, expression of highly hydrophilic polypeptides termed LEA proteins has been linked to the survival of plants and animals during periods of water stress such as freezing and drying. Several classification schemes for LEA proteins have been proposed and the brine shrimp, Artemia franciscana, is the only known animal that naturally expresses LEA proteins from three different classification groups (groups 1, 3, and 6). LEA proteins occur in several subcellular compartments including the cytosol and mitochondria. To investigate the biochemical properties of LEA proteins, it is important to characterize their structure. LEA proteins are intrinsically disordered in aqueous solution and the exact structure and function of these proteins is still poorly defined and understood. We hypothesized that LEA proteins will show different protective properties depending on the target enzyme (e.g. lactate dehydrogenase vs. succinate dehydrogenase). We found, that a purified group 1 LEA protein from A. franciscana (AfrLEA 1.1) helped to retain enzyme activity after desiccation of lactate dehydrogenase (LDH) and dry storage of the enzyme for 1, 3 and 7 days in the presence or absence of bovine serum albumin or trehalose. Increased concentration of purified AfrLEA 1.1, increased the percentage of LDH activity retained after desiccation. To further characterize AfrLEA 1.1, we cloned, expressed, and purified the protein in E. coli. We purified untagged AfrLEA 1.1 protein by affinity chromatography via intein mediated purification with an affinity based chitin‐binding system; a novel protein purification system which utilizes the inducible self‐cleavage activity of protein splicing elements to separate the target protein from the affinity tag. Furthermore, AfrLEA1.1 was expressed in Nicotiana tabacum to investigate if the protein increases drought tolerance of this model plant.Support or Funding InformationSupported by NSF IOS‐1456809
Shifting Sands: Modulating Interactions and Outputs of the CHIP‐Hsp70/HOP‐Hsp70 Protein Quality Control Complexes
Authors: Page Richard C , Zhang Huaqun , Cottingim Kelsey , VanPelt Jamie , Nix Jay C , Schisler Jonathan 
Published: June 2021

The 70‐kilodalton heat shock protein (Hsp70) interacts with tetratricopeptide repeat (TPR) domains of CHIP (C‐terminus of Hsp70 Interacting Protein) and HOP (Hsp Organizing Protein) using a two‐carboxylate clamp binding mechanism. Differential affinity for the TPR domains of CHIP and HOP are achieved through interactions with the six residues preceding the carboxy‐terminal Asp641 of Hsp70. In particular, phosphorylation of Hsp70 Thr636 produces a dramatic swing in binding affinities that shift preferential formation of CHIP/Hsp70 complexes to preferential formation of HOP/Hsp70 complexes. Given that CHIP‐Hsp70 complexes promote ubiquitin‐mediated degradation of Hsp70‐chaperoned clients while HOP‐Hsp70 complexes promote refolding of Hsp70‐chaperoned clients, phosphorylation of Hsp70 Thr636 acts as a switch that directs the output and function of cellular protein quality control. Herein, through biophysical assays and new structures of CHIP‐Hsp70 and Hop‐Hsp70 we identify the molecular mechanism that enables phosphorylation‐driven switching that directs interactions within the CHIP‐Hsp70/HOP‐Hsp70 protein quality control complexes. We also present a structure‐guided mutation of Hsp70 that bypasses Thr636 phosphorylation‐driven switching by recovering affinity of CHIP for phosphorylated Hsp70, thereby redirecting Hsp70 to preferentially bind to CHIP. This structure‐guided mutation corrects a binding defect present in wild type CHIP and provides a system for studying the effect of shifting output of the CHIP‐Hsp70/HOP‐Hsp70 protein quality control complexes toward chaperoned ubiquitination via the CHIP‐Hsp70 complex.Support or Funding InformationThe authors acknowledge financial support from the US National Science Foundation (Award No. MCB 1552113 to RCP), the American Heart Association (Award No. 16SDG26960000 to RCP), the Burroughs Wellcome Fund (Award No. 1014031 to RCP), and institutional support from Miami University through the Robert H. and Nancy J. Blayney Professorship (to RCP). The Advanced Light Source is supported by the US Department of Energy under contract number DE‐AC03‐76SF00098 at Lawrence Berkeley National Laboratory.
Interactions of Rat Embryonic Hippocampal Neuronal Stem Cell on Au‐nanowire Arrays and Gold Nano‐Film Surface
Authors: Islam Asiful 
Published: June 2021

Hippocampal neuronal stem cell culture on the nano‐substrates has introduced new era in nano‐neuroscience research. Neurons were cultured on the gold nano‐wire and nano‐film surfaces to see the viability and interactions between neurons and nanoscale surfaces. Anodization of aluminum templates created nanoporous alumina tubes arranged parallel to each other and electrodeposition using gold solution (AuHCl4) resulted in arrays of gold nanowires (GNWs) inside the pores. For investigation of Au‐nano‐neuronal interactions we have cultured embryonic day 18 rat hippocampal neurons on the surface of gold nanowires and surfaces. For preliminary understanding of the neuronal growth and connectivity we studied the images of nano‐neuronal interactions by using optical, fluorescence and scanning electron microscopy (SEM). For adhesion of neurons to nano‐arrays and nano‐surfaces we used bioconjugating protein coating Poly‐D‐Lysine (PDL). The rat hippocampus tissues were mechanically dissolved into neuronal cells and cultured on top of the gold nano‐wire (GNW) and flim (GNF) surfaces and preserved at 37° C constant temperatures in a 5% CO2 incubator. These neurons on the GNW and GNF surfaces started to grow from day 2 and survived up to 25 days or more. The extracellular protein PDL acted as an intermediate substance for neurites growth on the nano films slips. Without a PDL coating layer showed no or very little growth of neurons on the GNF substrates. We demonstrated well‐defined neuronal networks on Au‐nanowire arrays and GNF. The neurons attached with the nanowires surfaces by PDL, which is a positively charged poly‐peptide and plays a vital role in neurites growth on the nanowire arrays. The pre‐and post‐synaptic effects of neuronal interactions on the surfaces of nanowires were measured by Ca+ imaging in keck microscope. This study is the initial result for implementing the gold nano‐substrates to record the electrical signals from the neurons through gold nano‐films or nano‐wires.Support or Funding InformationNSF
Facial Imagery BMI Algorithm correlates with Normal and Overweight Measured BMI
Authors: Barr Makenzie L , Famodu Oluremi A , Guo Guodong , Colby Sarah E , Olfert Melissa Diann 
Published: June 2021

Efficient procedures to determine health status are in high demand in today's generation. Body Mass Index (BMI) is a global method for determining an individual's health status. This research exploration is to identify if a facial image (photograph) can identify participant's BMI correctly. Sample of 1,210 young adults with a facial image and objective height and weight were used for analysis. Facial BMI (fBMI) was measured through the Local Binary Pattern (LBP)/Active Shape Model (ASM) was used to detect 76 points on each face and measured BMI (mBMI) was calculated by weight in kilograms divided by height in meters squared. Correlation analysis of fBMI to mBMI showed significant correlation between BMIs in the normal and overweight categories (p<.0001). Further analysis indicated the measure to be less efficacious in underweight and obese participants. Matched pairs data for each individual, there was a range of 14.73–49.74 for mBMI and a narrowed spread for fBMI (range = 16.29–28.85) indicating that fBMI detected participant BMI 0.4212 less than mBMI (p<.0004). BMI categories used included: less than 18.5 BMI (0), 18.5–24.9 (1), 25.0–29.9 (2), and equal to or above 30 (3). mBMI had representation of categories across 0–3 BMI, while fBMI representation included just 0–2. This shows less sensitivity of the algorithm to obese individuals. Contingency table analysis indicted 109 participants in the 3rd category of mBMI were placed into a lower category for fBMI. Agreement test for symmetry shows significant disagreement 95% CI [0.0618,0.1446] (p<.0001). Facial imagery identification of health status is a useful measure in human research however; more sensitive measures to identify underweight and obese individuals are warranted.Support or Funding InformationApproval to use the data set was granted by the University of Tennessee Institutional Review Board prior to study implementation. This material is based upon work that is supported by the National Institute of Food and Agriculture, U.S. Department of Agriculture, under award number 2014‐67001‐21851.
Do Cord Serum Ferritin Concentrations Serve as an Index of Neonatal Iron Status?
Authors: Delaney Katherine M. , Fleming Robert K. , Guillet Ronnie , Queenan Ruth Anne , Pressman Eva K. , O'Brien Kimberly O. 
Published: June 2021

Low iron stores at birth have been associated with adverse health outcomes. Although the importance of this issue has been highlighted, few studies have examined the relationship between indicators of iron status and hemoglobin concentrations at birth. To address this issue, we measured a broad panel of iron status indicators and associated regulatory hormones in 471 infants born from two obstetric populations known to be at increased risk of maternal iron deficiency and anemia: pregnant adolescents (n=280) and women with a multiple pregnancy (n=191). Neonatal cord blood and maternal blood samples were obtained at delivery, and used to evaluate concentrations of hemoglobin (Hb), serum iron (Fe), ferritin (SF), soluble transferrin receptor (sTfR), hepcidin, interleukin‐6 (IL‐6), erythropoietin (EPO), folate and vitamin B12. Delivery occurred at average 39 ± 3 weeks of gestation in adolescents, and at 34 ± 3 weeks in women carrying multiples. When analyzed as a whole, cord hepcidin was found to be inversely correlated with hemoglobin (Hb) (p = 0.0134) and with serum iron (p < 0.001), while positively correlated with IL‐6 (p < 0.0001). No significant associations were found between maternal hepcidin concentrations and neonatal markers of Fe status, including cord hepcidin. Despite serving as a marker of iron status in other settings, ferritin concentrations in cord blood were not significantly associated with any of the Fe status indicators evaluated, and were instead inversely associated with Hb (p = 0.0032). Excluding values from neonates with elevated cord IL6 concentrations did not alter these findings. Additionally, no correlation was observed between cord IL‐6 concentrations and Hb. These results challenge the current understanding that serum ferritin can serve as an independent marker of Fe status at birth. Our observations underscore the need for further identification and characterization of biomarkers of fetal and neonatal Fe status, and their relationships with outcomes historically attributed to poor iron status during this developmental time frame.Support or Funding InformationThis work was supported by US Department of Agriculture (USDA) and the Gerber Foundation
Following a dietary pattern based on Dietary Guidelines for Americans may lead to reduced preference for sweet taste
Authors: Lee Fanny , Kishimura Kathleen , Horn William , Ilyas Amar , Que Excel , Hall Joanne , Welch Lucas , Krishnan Sridevi , Keim Nancy L 
Published: June 2021

ObjectiveDietary intake of added sugars in the United States is significantly higher than what is recommended by the Dietary Guidelines for Americans (DGA) and by other health organizations. There is limited research on how reducing the intake of added sugars would affect or change taste perception related to sugar. Our objective was to determine if sweet taste threshold and sweet preference changes in response to a diet intervention based on the recommendations in the 2010 DGA compared to an intervention based on the typical American diet (TAD) as described by recent surveys of U.S. adults.MethodsData for this report is from an eight‐week controlled feeding trial. Overweight or obese women, with insulin resistance and/or dyslipidemia, aged 20–65 years were randomized into one of two diet groups: the DGA diet or the TAD. Detection taste threshold was determined using a three‐alternative‐forced choice method and sweet preference was measured using the Monell forced‐choice, paired‐comparison tracking procedure. Measurements were obtained prior to the dietary intervention at baseline (BL), and after the diet intervention (ADI) to evaluate changes in taste acuity and hedonic preference. Data were log transformed, and analysis of covariance was used to identify differences between the two diet groups. In addition, the change in acuity and hedonic preference was calculated as ADI‐BL. Wilcoxon's rank test was used to identify differences in these parameters between the two groups. This is an on‐going study, with more participant cohorts being added to reach n = 44.ResultsPreliminary results were generated for the first 16 women (Age: DGA ‐ 45.0, TAD‐42.5 y; BMI: DGA – 30.4, TAD – 33.0 kg/m2) who have completed the study. Usual energy intake (kcals), and percent‐added sugars or sweet‐food intake were not different at BL between DGA and TAD (p = 0.92, 0.63, 0.92, respectively). There was no significant difference (p > 0.05) between diets in the change in sweet threshold or sweet preference. The DGA intervention, however, resulted in a larger reduction in the level of preferred sweetness compared to the TAD diet, when controlling for BL preference (p = 0.03).ConclusionsConsuming a diet following the DGA may possibly lower preference for sweet foods when compared to a TAD. Further, data from the complete cohort will be used to add to this report upon study completion.Support or Funding InformationFunded by National Dairy Council and USDA, ARS CRIS project #2032 51530 022 00D
Coconut oil prevents hepatic steatitis but not adipose inflammation in obese mice
Authors: Picklo Matthew , Idso Joseph , Zeng Huawei 
Published: June 2021

While saturated fat intake is associated with obesity and its comorbidities, there are little data indicating the impact of specific saturated fatty acids (SFA).In particular, data are lacking in which only SFA type, but not other fatty acids, is changed. In this work, we tested the hypothesis that intake of obesogenicdiets containing medium chain SFA reduce hepatic steatosis and insulin resistance. Male, C57BL/6J mice were fedobesogenic diets of 48% energy (en) fat (28 % SFA, 14% oleic acid, and 6% polyunsaturated fatty acid) or a control diet with 16% en fat (5% SFA, 4% oleicacid, and 7% PUFA) for 16 weeks. Obesogenic groups were divided by SFA source:coconut oil‐based (CCO) with high lauric acid, a palm‐oil based (PO) with palmitic acid and stearic acids, and a MIX group with similar levels of the SFAs.All mice eating the obesogenic diets became obese compared to the control group. While all obese animals were insulin resistant, PO animals had higher insulin resistance (assessed by HOMA‐IR) than CCO and MIX animals. Hepatic triacylglycerides (TAG) were elevated in the PO and MIX groups, but not the CCO group. The accumulation of hepatic lipid was confirmed with histological analysis. Hepatic expression of the inflammatory cytokine MCP‐1 was elevated by intake of the PO diet, but not the CCO and MIX diets. On the other hand, expression of MCP‐1 and TNF alpha in visceral adipose was elevated by all three obesogenic diets. Hepatic protein levels of stearoyl‐CoA desaturase 1(SCD‐1), fatty acid synthase (FASN), but not acetyl CoA carboxylase 1 (ACC1), were reduced by intake of CcO and PO diets. These data indicate that intake of CCO has selective protective effects against hepatic steatosis but not adipose dysfunction. These data indicate a decrease in de novo lipogenes is induced by the obesogenicdiets and that perturbation of other processes such as VLDL secretion or fatty acid oxidation impact hepatic TAG deposition and are SFA‐type dependent.Support or Funding InformationThis work was supported by U.S. Department of Agriculture through USDA‐ARS project 5450‐51000‐048‐00D.