bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structure‐Function Studies of Deinococcus radiodurans ADP Glucose Pyrophosphorylase: Role of Ser48 in Allosteric Regulation
Authors: Le‐Pham Ashley , Qoborsi Jeries , Ong Leo , Orry Andrew , Meyer Christopher R 
Published: June 2021

Adenosine Diphosphate Glucose Pyrophosphorylase (ADPG PPase) is an allosterically regulated enzyme that functions as the rate‐limiting step of starch synthesis in plants and glycogen synthesis in bacteria. Because starch is a source of renewable and biodegradable carbon, ADPG PPase is an attractive target for protein engineering to increase biomass yield in crops. The microbial versions of this enzyme are quite diverse in their regulatory and physical properties; some of these properties would be useful to incorporate into transgenic crops to enhance starch production. While a number of ADPG PPases have been kinetically characterized, there is only one published x ray structure (PDB 3BRK) of an inhibited form. Very little is known about the enzyme from Deinococcus radiodurans (D. rad), an extremophile that is resistant to ionizing radiation and harsh growth conditions. When comparing the amino acid sequence of this enzyme to other characterized ADPG PPases, it was noted that position 48 differed with a serine substituted for alanine in a region known to be important for allostery. To probe the role of Ser‐48, the S48A enzyme was generated by site‐directed mutagenesis and the recombinant altered D. rad ADPG PPases successfully expressed in E. coli and purified via a scheme that includes anion exchange chromatography, size exclusion chromatography, and affinity chromatography. Initial studies on the S48A enzyme in the absence of activators have shown a dramatic 20‐fold increase in the apparent affinity for the substrate ATP, a 3‐fold increase in apparent affinity for the cofactor magnesium, and a 4‐fold increase in Vmax compared to wild‐type. Interestingly, in the presence of the activator FBP there was little change in the apparent binding affinity for substrates or Vmax compared to WT which displays a 14‐fold increase in Vmax and 12‐fold and 3‐fold increase in apparent affinity for ATP and magnesium, respectively. Similarly, in the presence of F6P, there were not a very large increase in Vmax or higher apparent affinity for ATP for the S48A enzyme, but there was a 9‐fold difference in Vmax and a 12‐fold and 2‐fold increase in apparent binding affinity for ATP and magnesium for WT, respectively. The WT enzyme also displayed higher apparent affinity for FBP and F6P compared to the S48A enzyme. The alanine substitution appears to result in an enzyme form that is partially activated but relatively insensitive to activators. Further kinetic characterization of S48A in the presence of sulfate and the inhibitor phosphate is in progress. With respect to physical characterization, two crystallization conditions for S48A, one including imidazole and the other with lithium sulfate and PEG, were found to yield preliminary results. Further crystallization trials are in progress as a first step in elucidating the three‐dimensional structure.Support or Funding InformationSupported in part by NSF and NSF BIO MCB grant #0448676.
Metabolite‐Driven Modifications: Protein Acylations Elucidate Substrate Metabolism in Syntrophic Bacteria
Authors: Nguyen Hong Hanh T. , Nguyen Phuong H.N. , Gunsalus Robert P. , McInerney Michael J. , Loo Joseph A. , Ogorzalek Loo Rachel R. 
Published: June 2021

Lysine acylation is a rising post‐translational modification (PTM) family that includes acetylation and similar short‐chain acylations. Reversible acylation has emerged as an important regulatory mechanism coordinating metabolism in response to changes in nutrient availability and metabolic fluxes. Since the levels of lysine acylations correlate with the levels of corresponding acyl‐CoAs and syntrophic bacteria produce complex central metabolic intermediates during fatty acid and aromatic compounds degradation, we used mass spectrometry to simultaneously reveal and evaluate all the acyl‐modifications in the syntrophs Syntrophomonas wolfei and Syntrophus aciditrophicus. Detected modifications provided insights into substrate metabolism regulations in these organisms living at the thermodynamic limits of microbial growth.Support or Funding InformationThis work is funded by the US Department of Energy (UCLA Institute of Genomics and Proteomics, DE‐FC03‐02ER63421 to J. Loo) and the National Institutes of Health (R01GM085402 to J. Loo and R. Ogorzalek Loo).
The Cornell NutriPhone: Enabling Precision Nutrition
Authors: Mehta Saurabh , Erickson David C. 
Published: June 2021

The progress in modern technology and advances in biomedical engineering over the last few years have now made it possible to address a long‐term challenge of accurately and inexpensively assessing nutritional status at the point‐of‐care in both developed and developing country settings. This will facilitate improvements in designing and implementing nutritional interventions, generation of accurate representations of micronutrient status globally, and development and delivery of targeted nutritional programming.The Cornell NutriPhone has resulted through a collaboration between scientists and engineers in Nutritional Sciences and Engineering at Cornell University in the time span of two years. When we began this partnership, our initial targets were to develop diagnostic tools that were affordable and accessible for populations in both resource‐limited and resource‐rich settings. From a technical standpoint, we also decided to focus on adapting conventional laboratory assays and gold standard methods rather than focusing on proxy biomarkers that are widely used in most field‐based rapid diagnostic tests.We now have prototypes for low‐cost accurate quantitative determination of several micronutrients including vitamin D concentrations from a drop of blood at the point‐of‐care. Some of the tests are based on competitive antibody recognition, similar to other standard immunoassays. Instead of using an enzymatic or radioactive label however, the antibodies are conjugated to 30nm gold nano particles. The nano particles have a strong red color characteristic of their surface plasmon resonance. For the quantification of micronutrient levels, the brightness change is captured using the smartphone's camera after inserting the test strip in the smartphone accessory. The smartphone app then uses an algorithm to: scan for a region of most uniform color development, compute an averaged brightness difference, and estimate the concentration from the built‐in calibration curve.We are currently conducting field validation studies in the U.S., India, and Ecuador to establish accuracy and reliability of the test and refine usability and interface of the software. In the short‐term, we are working on expanding the capability of the NutriPhone to other micronutrients and mutiplexing several nutrients on one chip/strip. Our long‐term vision is to equip health care facilities or community workers even in remote regions of the world with one such device to enable precision nutrition globally.Support or Funding InformationNational Science Foundation; Atkinson Center for a Sustainable Future
Attracting Attention: Parent Perceptions of Coverlines on HomeStyles Guides
Authors: Martin‐Biggers Jennifer T , Delaney Colleen , Povis‐Alleman Gayle , Hongu Nobuko , Worobey John , Byrd‐Bredbenner Carol 
Published: June 2021

This study examined parent perceptions of coverlines used on 12 colorful 4‐page mini‐magazine‐style informational guides designed to improve weight‐related home environment and lifestyle practices in families with preschool children. Coverlines are short phrases designed to attract attention and motivate individuals to read articles in magazines. Health communication researchers developed coverlines based on results from content analysis of popular women and parenting magazine coverlines, asked 77 mothers of young children to rate how much each coverline would motivate them to read a short article related to the coverline, then selected the most highly rated coverlines for placement on guide covers. Examples of some highly rated coverlines are: “Breakfast is for champions! Feed your little super heroes”, “Secrets for successful family meals”, “Surprising links between family playtime and health”, “Who knew? Fruits and veggies are the new power foods”, “Make mealtime memories your kids will treasure”, “Smart, no‐cost family playtime ideas”, “Eat, play, sleep and love your family like never before”, and “Brilliant ideas for meals without squeals”. Coverlines were inserted in colorful text blocks positioned on the full‐color photograph forming the cover of the informational guides. Cognitive interviews were conducted with 117 English‐ and 112 Spanish‐speaking parents to determine their feelings about the coverlines and whether they believed the coverlines would make them and parents like them want to read the guide. The cognitive interviews of the coverlines were conducted after parents had read a guide. Almost all parents felt the coverlines would make them and other parents want to read the information in the guides. Parents also described the coverlines as “attention‐grabbing” and “catchy”. Participants made a few minor semantic change suggestions. Using motivating coverlines has the potential to increase intention and desire to read health promotion materials. Health communicators should consider incorporating evidence‐based, consumer‐tested coverlines in written materials to pique consumer interest.Support or Funding InformationUSDA NIFA #2011‐68001‐30170
Validity of anthropometric measurements, BMI and child growth assessments conducted by Head Start teachers: training needs for longitudinal child growth surveillance
Authors: Esquivel Monica Kazlausky , Fialksowski Marie K , Nigg Claudio R , Braun Kathryn L , Li Fenfang , Wilkens Lynne , Novotny Rachel Kazlausky 
Published: June 2021

BackgroundHigh prevalence of childhood obesity and associated diseases have been observed in the US Affiliated Pacific but no system for monitoring young child obesity in the region is available. Head Start (HS) preschools located throughout the region complete bi‐annual growth assessments to assess childhood obesity and can potentially contribute to a growth monitoring system.ObjectiveTo assess the relative validity of HS anthropometric measurements and growth assessments for potential use in a surveillance system.MethodsThis was a validation study of HS child anthropometric measurements taken by HS teachers against standardized researcher measurements for height and weight. Data from 19 HS classrooms (135 children) that were previously enrolled in a larger randomized control trial were included in this study. Differences in height, weight, BMI and CDC BMI categories between HS teachers and a standardized researcher were analyzed using paired t‐tests, controlling for child age at time of measurement to quantify differences in HS and researcher measured heights and weights. weighted Kappa statistics determined agreement between the methods on BMI weight categories adjusting for age at measurement with post‐hoc paired t‐tests to analyze differences in BMI categories by measurement method.ResultsHS teacher growth assessments did not significantly differ from those of a standardized researcher and weighted Kappa statistics for agreement based on CDC BMI categories showed reasonable agreement between the two methods (weighted kappa=0.72).ConclusionsAt the programmatic level, this level of agreement suggests that HS measurements are adequate for determining prevalence of BMI categories. However, they may not provide sufficient precision to assess changes over time in individuals and research studies (ie: measuring intervention or program effect). Anthropometric data from HS centers may contribute to a system for childhood overweight and obesity surveillance in the US Affiliated Pacific, however, further training on conducting measurements would be necessary to track individual changes over time.Support or Funding InformationThis project is supported by the Agriculture and Food Research Initiative Grant no. 2011‐68001‐30335 from the USDA National Institute of Food and Agricultural Science Enhancement Coordinated Agricultural Program
Effect of obesity on liver metabolic and morphological profile in Zucker rats
Authors: Hakkak Reza , Korourian Soheila , Evans Teresa , Pavliv Oleksanda , Harb Alex , Melnyk Stepan 
Published: June 2021

Fatty liver disease, ranging from simple hepatic steatosis and nonalcoholic staetohepatitis to cirrhosis, created a major health problem in the USA and world. Animal and human study showed that obesity can play important role in promotion of fatty liver. Our previous results demonstrated that obesity in Zuckar rats caused a significant morphological changes in liver: increase in fatty steatosis to small foci of mononuclear infiltration with perturbation in one carbon group metabolism donor S‐adenosylhomocysteine (SAM) and its product S‐adenosylhomocysteine (SAH) and SAM/SAH “methylation ratio”. The main objective of this study was to further investigate and compare metabolic profile of liver steatoss of lean and obese Zucker rats. After one week of acclimation, six‐weeks old female lean (n=26) and obese (n=20) Zucker rats were fed AIN‐93 G diet and sacrificed 155 days later. Liver samples were analyzed for free reduced glutathione (GSH), oxidized glutathione (GSSG), GSH/GSSG ratio, nitroglutathione (GSNO), and 3‐nitroTyrosine (3NT) using LC‐MS and HPLC‐ECD techniques. Our results shows that obesity caused: 1) a significant increase (p<0.05) liver steatosis; 2) a significant (P<0.05) decrease level of GSH and, on contrary, significant (P<0.005) increase level of GSSG; 3) crossing in glutathione level, that leaded to significant (P<0.0005) decrease of GSH/GSSG ratio, and 4) in contrast, significant (P<0.05) increase both of 3NT and GSNO. In summary, liver morphological and “methylation ratio” changes in obese rats are accompanied by significant oxidative and nitrosative stress. These metabolic changes must be consider in prevent of liver damages.Support or Funding Information(Supported by USDA and ABI grants to RH and SM).
Decreased beige adipocyte number and mitochondrial respiration coincide with reduced FGF21 gene expression in Sprague Dawley rats fed prenatal low protein and postnatal high fat diets
Authors: Claycombe Kate J , Vomhof‐DeKrey Emilie E , Garcia Rolando , Johnson William T , Uthus Eric , Roemmich James N 
Published: June 2021

We have shown that protein malnutrition during fetal growth followed bypostnatal high‐fat diets results in a rapid increase in subcutaneous adiposetissue mass in the offspring contributing to development of obesity and insulin resistance. Recent studies have shown that the absence of a key transcription factor PR domain containing 16 (PRDM16) and fibroblast growth factor 21 (FGF21)are involved in conversion of precursor white adipocytes into more mitochondrial enriched and metabolically active beige adipocytes cause marked enlargement of the subcutaneous adipose tissue. Our hypothesis is that amaternal LP and postnatal HF diets increase the risk of development of obesity and insulin resistance in offspring, in part, by reducing the conversion of precursor white adipocytes into beige adipocytes in the subcutaneous adiposetissue of offspring. Using obese‐prone Sprague‐Dawley rats fed 8% low protein(LP) or 20% normal protein (NP) diets for 3 wk prior to conception and throughout pregnancy and lactation followed by 12 wks of 10% normal fat (NF) or 45% high fat (HF) diet feeding, we investigated whether prenatal LP and postnatal HF diets affect beige adipocyte number and oxidative respiratory function in subcutaneous adipose tissue. Results showed that subcutaneous adipose and liver fibroblast growth factor 21 (FGF21), PRDM16, and beigeadipocyte marker CD137, mRNA increase with postnatal HF diet in maternal NP group mice. In contrast, mice fed maternal LP and postnatal HF diets showed no increase in subcutaneous adipose tissue mitochondrial copy number, oxygen consumption rate, FGF21, PRDM16, and CD137 mRNA. These findings suggest that high‐fat diet fed offspring from mothers that consumed a low‐protein diet have reduced induction of beige adipocytes in subcutaneous adipose tissue and that this may be part of the mechanism by which maternal protein malnutrition causes offspring obesity and metabolic alterations.Support or Funding InformationThis work was supported by USDA Agricultural Research Service Project #3062‐51000‐052‐00D.
The Effect of Carotenoids on Transforming Growth Factor β1‐induced Fibrogenesis in LX‐2 cells, a Human Hepatic Stellate Cell Line
Authors: Bae Minkyung , Lee Ji‐Young 
Published: June 2021

Non‐alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in the United States. In response to oxidative stress or inflammation, simple steatosis can progress to non‐alcoholic steatohepatitis (NASH), an advanced form of NAFLD. Fibrosis is one of key features of NASH with increased accumulation of extracellular matrix (ECM) in the liver. Hepatic stellate cells (HSCs) play important roles in the development of liver fibrosis as they are the primary source of ECM in the damaged liver. We previously demonstrated that astaxanthin (ASTX), a xanthophyll carotenoid, prevents the activation of HSCs and attenuated the expression of fibrogenic markers, such as α‐smooth muscle actin (α‐SMA) and procollagen type I α1 (COL1A1) in LX‐2 (a human HSC cell line) as well as primary mouse and human HSCs. The objective of this study was to compare the efficacy of other carotenoids, including lycopene, lutein, zeaxanthin and canthaxanthin, in inhibiting HSC activation with that of ASTX in LX‐2 cells. Lycopene is a carotene while the other carotenoids are xanthophylls with very similar structure. LX‐2 cells were treated with 0, 10, 25, 50 and 100 μM of each carotenoid for 24 h to measure cytotoxicity. While most cells were viable with all concentrations of ASTX and zeaxanthin, cells treated with 100 μM of lycopene, lutein or canthaxanthin were ~60–70% viable. To evaluate the effect of the carotenoids on the activation of LX‐2 cells by transforming growth factor β1 (TGFβ1), a potent fibrogenic cytokine, the cells were pretreated with 25 μM each carotenoid for 24 h, followed by the treatment with 4 ng/mL for 24 h. TGFβ1 treatment markedly increased mRNA of α‐SMA and COL1A1 in LX‐2 cells by ~4‐fold and 5‐fold, respectively. ASTX repressed TGFβ1‐induced expression of α‐SMA and COL1A1 by ~60% and ~30%, respectively. Lutein also decreased the expression of α‐SMA and COL1A1 by 85% and 70%, respectively. Basal and TGFβ1‐induced α‐SMA and COL1A1 protein levels were noticeably decreased by lutein and ASTX with lutein being more potent. TGFβ1‐induced COL1A1 protein expression was attenuated by lycopene, zeaxanthin and canthaxanthin, albeit less than lutein and ASTX. In conclusion, the results suggest that ASTX and lutein inhibit TGFβ1‐induced HSC activation and fibrogenic gene expression while zeaxanthin and canthaxanthin did not exert the same effect despite their similar structure to ASTX and lutein.Support or Funding InformationUnited States Department of Agriculture, AFRI (2012‐67018‐19290)
Influence of temperature and humidity on the stability of carotenoids in biofortified maize genotypes
Authors: Ortiz Darwin , Rocheford Torbert , Ferruzzi Mario 
Published: June 2021

Maize is a staple crop that has been the subject of biofortification efforts to increase the natural content of provitamin A carotenoids. While significant progress towards increasing provitamin A carotenoid content in maize varieties has been made, post‐harvest handling factors that influence carotenoids stability during storage has not been fully established. The objectives of this study were to determine carotenoid profiles of six selected provitamin A biofortified maize genotypes at various developmental stages, and assess the stability of carotenoids in maize kernels during controlled storage conditions (12 month‐period) including elevated temperature and relative humidity (RH). There were no significant changes in the content of individual carotenoids within genotypes during kernel development from 45 days after pollination through the time of harvest. Carotenoid losses through traditional grain drying were also minimal (<9%). However, stability of carotenoids in maize kernels over storage time after harvest was found to be dependent on both temperature and humidity, with variation observed among genotypes. Different forms of provitamin A carotenoids follow similar degradation rate. Carotenoid degradation rate appears to be independent of initial carotenoid concentration. Genotype (C17/DE3) had a degradation rate 2× faster than the other genotypes evaluated (P<0.001). These differences in carotenoid stability to controlled storage were attributed, in part, to observed differences in physical properties of the kernels (surface area and porosity). These results support the notion that effective control of moisture content and temperature of the kernels during storage conditions is essential to reduce the speed of degradative reactions.Support or Funding InformationFunding provided by NSF, Harvest Plus, Colciencias and Fulbright‐Colombia.