Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “lipids”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 289 records · Page 16
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Calcium-triggered fusion of lipid membranes is enabled by amphiphilic nanoparticles

Significance Lipid membrane fusion is a critical component of biological transport, communication, and developmental processes. The fusion reaction is kinetically constrained since it contains multiple large energy barriers, so proteins and ions are used by natural systems to intervene and catalyze the reaction toward biologically relevant timescales. Here, we demonstrate how amphiphilic nanoparticles can prime lipid membranes for fusion so that complete fusion proceeds only upon exposure to an excess of calcium or other stimulus that would stress the outer leaflet. This is a major advance in the nascent field of controlled fusion and may unlock new avenues of research on how nanomaterials can be designed from first principles to perform targeted functional roles in biological systems.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2024

FatPlants: a comprehensive information system for lipid-related genes and metabolic pathways in plants

Abstract FatPlants, an open-access, web-based database, consolidates data, annotations, analysis results, and visualizations of lipid-related genes, proteins, and metabolic pathways in plants. Serving as a minable resource, FatPlants offers a user-friendly interface for facilitating studies into the regulation of plant lipid metabolism and supporting breeding efforts aimed at increasing crop oil content. This web resource, developed using data derived from our own research, curated from public resources, and gleaned from academic literature, comprises information on known fatty-acid-related proteins, genes, and pathways in multiple plants, with an emphasis on Glycine max, Arabidopsis thaliana, and Camelina sativa. Furthermore, the platform includes machine-learning based methods and navigation tools designed to aid in characterizing metabolic pathways and protein interactions. Comprehensive gene and protein information cards, a Basic Local Alignment Search Tool search function, similar structure search capacities from AphaFold, and ChatGPT-based query for protein information are additional features. Database URL: https://www.fatplants.net/

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2021

LDIP cooperates with SEIPIN and LDAP to facilitate lipid droplet biogenesis in Arabidopsis

Cytoplasmic lipid droplets (LDs) are evolutionarily conserved organelles that store neutral lipids and play critical roles in plant growth, development, and stress responses. However, the molecular mechanisms underlying their biogenesis at the endoplasmic reticulum (ER) remain obscure. Here we show that a recently identified protein termed LD-associated protein [LDAP]-interacting protein (LDIP) works together with both endoplasmic reticulum-localized SEIPIN and the LD-coat protein LDAP to facilitate LD formation in Arabidopsis thaliana. Heterologous expression in insect cells demonstrated that LDAP is required for the targeting of LDIP to the LD surface, and both proteins are required for the production of normal numbers and sizes of LDs in plant cells. LDIP also interacts with SEIPIN via a conserved hydrophobic helix in SEIPIN and LDIP functions together with SEIPIN to modulate LD numbers and sizes in plants. Further, the co-expression of both proteins is required to restore normal LD production in SEIPIN-deficient yeast cells. These data, combined with the analogous function of LDIP to a mammalian protein called LD Assembly Factor 1, are discussed in the context of a new model for LD biogenesis in plant cells with evolutionary connections to LD biogenesis in other eukaryotes.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2024

Packaging “vegetable oils”: Insights into plant lipid droplet proteins

Abstract Plant neutral lipids, also known as “vegetable oils”, are synthesized within the endoplasmic reticulum (ER) membrane and packaged into subcellular compartments called lipid droplets (LDs) for stable storage in the cytoplasm. The biogenesis, modulation, and degradation of cytoplasmic LDs in plant cells are orchestrated by a variety of proteins localized to the ER, LDs, and peroxisomes. Recent studies of these LD-related proteins have greatly advanced our understanding of LDs not only as steady oil depots in seeds but also as dynamic cell organelles involved in numerous physiological processes in different tissues and developmental stages of plants. In the past 2 decades, technology advances in proteomics, transcriptomics, genome sequencing, cellular imaging and protein structural modeling have markedly expanded the inventory of LD-related proteins, provided unprecedented structural and functional insights into the protein machinery modulating LDs in plant cells, and shed new light on the functions of LDs in nonseed plant tissues as well as in unicellular algae. Here, we review critical advances in revealing new LD proteins in various plant tissues, point out structural and mechanistic insights into key proteins in LD biogenesis and dynamic modulation, and discuss future perspectives on bridging our knowledge gaps in plant LD biology.

Cai, Yingqi (ORCID:0000000203575809)↗
DOE OSTI2023

Distribution and abundance of tetraether lipid cyclization genes in terrestrial hot springs reflect pH

Many Archaea produce membrane-spanning lipids that enable life in extreme environments. These isoprenoid glycerol dibiphytanyl glycerol tetraethers (GDGTs) may contain up to eight cyclopentyl and one cyclohexyl ring, where higher degrees of cyclization are associated with more acidic, hotter or energy-limited conditions. Recently, the genes encoding GDGT ring synthases, grsAB, were identified in two Sulfolobaceae; however, the distribution and abundance of grs homologs across environments inhabited by these and related organisms remain a mystery. To address this, we examined the distribution of grs homologs in relation to environmental temperature and pH, from thermal springs across Earth, where sequences derive from metagenomes, metatranscriptomes, single-cell and cultivar genomes. The abundance of grs homologs shows a strong negative correlation to pH, but a weak positive correlation to temperature. Archaeal genomes and metagenome-assembled genomes (MAGs) that carry two or more grs copies are more abundant in low pH springs. We also find grs in 12 archaeal classes, with the most representatives in Thermoproteia, followed by MAGs of the uncultured Korarchaeia, Bathyarchaeia and Hadarchaeia, while several Nitrososphaeria encodes >3 copies. Furthermore, our findings highlight the key role of grs-catalysed lipid cyclization in archaeal diversification across hot and acidic environments.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2024

Lipid droplet-associated proteins in alcohol-associated fatty liver disease: A proteomic approach

The earliest manifestation of alcohol-associated liver disease (ALD) is steatosis characterized by deposition of fat in specialized organelles called lipid droplets (LDs). While alcohol administration causes a rise in LD numbers in the hepatocytes, little is known regarding their characteristics that allow their accumulation and size to increase. The aim of the present study is to gain insights into underlying pathophysiological mechanisms by investigating the ethanol-induced changes in hepatic LD proteome as a function of LD size. Adult male Wistar rats (180–200 g BW) were fed with ethanol liquid diet for 6 weeks. At sacrifice, large-, medium-, and small-sized hepatic LD subpopulations (LD1, LD2, and LD3, respectively) were isolated and subjected to morphological and proteomic analyses. Morphological analysis of LD1-LD3 fractions of ethanol-fed rats clearly demonstrated that LD1 contained larger LDs compared with LD2 and LD3 fractions. Our preliminary results from principal component analysis showed that the proteome of different-sized hepatic LD fractions was distinctly different. Proteomic data analysis identified over 2000 proteins in each LD fraction with significant alterations in protein abundance among the three LD fractions. Among the altered proteins, several were related to fat metabolism, including synthesis, incorporation of fatty acid, and lipolysis. Ingenuity pathway analysis revealed increased fatty acid synthesis, fatty acid incorporation, LD fusion, and reduced lipolysis in LD1 compared to LD3. Overall, the proteomic findings indicate that the increased level of protein that facilitates fusion of LDs combined with an increased association of negative regulators of lipolysis dictates the generation of large-sized LDs during the development of alcohol-associated hepatic steatosis. Several significantly altered proteins were identified in different-sized LDs isolated from livers of ethanol-fed rats. Ethanol-induced increases in specific proteins that hinder LD lipid metabolism led to the accumulation and persistence of large-sized LDs in the liver.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2024

TRPV3 activation by different agonists accompanied by lipid dissociation from the vanilloid site

TRPV3 represents both temperature- and ligand-activated transient receptor potential (TRP) channel. Physiologically relevant opening of TRPV3 channels by heat has been captured structurally, while opening by agonists has only been observed in structures of mutant channels. Here, we present cryo-EM structures that illuminate opening and inactivation of wild-type human TRPV3 in response to binding of two types of agonists: either the natural cannabinoid tetrahydrocannabivarin (THCV) or synthetic agonist 2-aminoethoxydiphenylborane (2-APB). We found that THCV binds to the vanilloid site, while 2-APB binds to the S1-S4 base and ARD-TMD linker sites. Despite binding to distally located sites, both agonists induce similar pore opening and cause dissociation of a lipid that occupies the vanilloid site in their absence. Our results uncover different but converging allosteric pathways through which small-molecule agonists activate TRPV3 and provide a framework for drug design and understanding the role of lipids in ion channel function.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2023

Systematic review of type 1 diabetes biomarkers reveals regulation in circulating proteins related to complement, lipid metabolism, and immune response

Type 1 diabetes (T1D) results from an autoimmune attack of the pancreatic β cells that progresses to dysglycemia and symptomatic hyperglycemia. Current biomarkers to track this evolution are limited, with development of islet autoantibodies marking the onset of autoimmunity and metabolic tests used to detect dysglycemia. Therefore, additional biomarkers are needed to better track disease initiation and progression. Multiple clinical studies have used proteomics to identify biomarker candidates. However, most of the studies were limited to the initial candidate identification, which needs to be further validated and have assays developed for clinical use. Here we curate these studies to help prioritize biomarker candidates for validation studies and to obtain a broader view of processes regulated during disease development. This systematic review was registered with Open Science Framework (https://doi.org/10.17605/OSF.IO/N8TSA). Using PRISMA guidelines, we conducted a systematic search of proteomics studies of T1D in the PubMed to identify putative protein biomarkers of the disease. Studies that performed mass spectrometry-based untargeted/targeted proteomic analysis of human serum/plasma of control, pre-seroconversion, post-seroconversion, and/or T1D-diagnosed subjects were included. For unbiased screening, 3 reviewers screened all the articles independently using the pre-determined criteria. A total of 13 studies met our inclusion criteria, resulting in the identification of 266 unique proteins, with 31 (11.6%) being identified across 3 or more studies. The circulating protein biomarkers were found to be enriched in complement, lipid metabolism, and immune response pathways, all of which are found to be dysregulated in different phases of T1D development. We found 2 subsets: 17 proteins (C3, C1R, C8G, C4B, IBP2, IBP3, ITIH1, ITIH2, BTD, APOE, TETN, C1S, C6A3, SAA4, ALS, SEPP1 and PI16) and 3 proteins (C3, CLUS and C4A) have consistent regulation in at least 2 independent studies at post-seroconversion and post-diagnosis compared to controls, respectively, making them strong candidates for clinical assay development. Biomarkers analyzed in this systematic review highlight alterations in specific biological processes in T1D, including complement, lipid metabolism, and immune response pathways, and may have potential for further use in the clinic as prognostic or diagnostic assays.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2024

Data for Pilot-Scale Processing of Miscanthus x giganteus for Recovery of Anthocyanins Integrated with Production of Microbial Lipids and Lignin-Rich Residue

Chemical-free hydrothermal pretreatment of Miscanthus x giganteus (Mxg) at the lab scale using high liquid-to-solid ratios resulted in the recovery of anthocyanins and enhanced enzymatic digestibility of residual biomass. In this study, the process is scaled up by using a continuous hydrothermal pretreatment reactor operated at a low liquid-to-solid ratio (50 % w/w solids) as an important step towards commercialization. Anthocyanin yield was 70 % w/w at the pilot scale (50 kg of Mxg), compared to the 94 % w/w yield achieved at the lab scale (0.5 g of Mxg). The pretreated biomass was subsequently refined mechanically using a disc mill to increase the accessibility of cellulose by cellulases. Enzymatic saccharification of the pretreated and disc-milled residue yielded 238 g/L sugar concentration by operating in fed-batch mode at 50 % w/v solids content. Two strains of Rhodosporidium toruloides were evaluated for converting the hydrolysate sugars into microbial lipids, and strain Y-6987 had the highest lipid titer (11.0 g/L). Further, the residue left after enzymatic saccharification was determined to be enriched 1.7-fold in the lignin content. This lignin-rich residue has value as a feedstock for the production of sustainable aviation fuel precursors and other high-value lignin-based chemicals. Hence the proposed biorefinery based on Mxg creates an opportunity for generating revenue from multiple high-value products. As the demand for biofuels and biobased products is rising, the biorefinery products from Mxg would create a niche in the industrial sector.

Conversion↗
DOE OSTI2025

Data for Redefining the Product Portfolio of Oilcane Bagasse Biorefinery: Recovering Natural Colorants, Vegetative Lipids and Sugars

:Bioenergy crops have been known for their ability to produce biofuels and bioproducts. In this study, the product portfolio of recently developed transgenic sugarcane (oilcane) bagasse has been redefined for recovering natural pigments (anthocyanins), sugars, and vegetative lipids. The total anthocyanin content in oilcane bagasse has been estimated as 92.9 ± 18.9 µg/g of dried bagasse with cyanidin-3-glucoside (13.5 ± 18.9 µg per g of dried bagasse) as the most prominent anthocyanin present. More than 85 % (w/w) of the total anthocyanins were recovered from oilcane bagasse at a pretreatment temperature of 150 °C for 15 min. These conditions for the hydrothermal pretreatment also led to a 2-fold increase in the glucose yield upon the enzymatic saccharification of the pretreated bagasse. Further, a 1.5-fold enrichment of the vegetative lipids was demonstrated in the pretreated residue. Re-defining green biorefineries with multiple high-value products in a zero-waste approach is the need of the hour for attaining sustainability.

Biomass Analytics↗
DOE OSTI2024

Data for Scale-up of Microbial Lipid and Bioethanol Production from Oilcane

Microbial oils are a sustainable biomass-derived substitute for liquid fuels and vegetable oils. Oilcane, an engineered sugarcane with superior feedstock characteristics for biodiesel production, is a promising candidate for bioconversion. This study describes the processing of oilcane stems into juice and hydrothermally pretreated lignocellulosic hydrolysate and their valorization to ethanol and microbial oil using Saccharomyces cerevisiae and engineered Rhodosporidium toruloides strains, respectively. A bioethanol titer of 106 g/L was obtained from S. cerevisiae grown on oilcane juice in a 3 L fermenter, and a lipid titer of 8.8 g/L was obtained from R. toruloides grown on oilcane hydrolysate in a 75 L fermenter. Oil was extracted from the R. toruloides cells using supercritical CO2, and the observed fatty acid profile was consistent with previous studies on this strain. These results demonstrate the feasibility of pilot-scale lipid production from oilcane hydrolysate as part of an integrated bioconversion strategy.

Bioproducts↗
DOE OSTI2021

Deep learning classification of lipid droplets in quantitative phase images

We report the application of supervised machine learning to the automated classification of lipid droplets in label-free, quantitative-phase images. By comparing various machine learning methods commonly used in biomedical imaging and remote sensing, we found convolutional neural networks to outperform others, both quantitatively and qualitatively. We describe our imaging approach, all implemented machine learning methods, and their performance with respect to computational efficiency, required training resources, and relative method performance measured across multiple metrics. Overall, our results indicate that quantitative-phase imaging coupled to machine learning enables accurate lipid droplet classification in single living cells. As such, the present paradigm presents an excellent alternative of the more common fluorescent and Raman imaging modalities by enabling label-free, ultra-low phototoxicity, and deeper insight into the thermodynamics of metabolism of single cells.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2022

HIV Env assembling is tightly modulated by lipid composition and cytoplasmic tail integrity

HIV envelope glycoprotein (Env) is a homotrimeric transmembrane protein which binds to receptors CD4, CCR5- CXCR4, leading to a cascade of conformational changes ultimately resulting in the entrance of the virus into the host cell. Its whole structure comprises an extracellular region, a transmembrane domain and a cytoplasmic region. While many efforts are carried in order to develop an effective vaccine specifically targeting the extracellular domain, less efforts are focus into regions close to the transmembrane region; mostly limited by the lack of structural knowledge within this domain. Thus, it is desirable to have a molecular description of the trimeric association of the transmembrane domain, as well as the membrane properties affecting their structure. We have carried molecular dynamic (MD) simulations of HIV transmembrane region in different lipid environments, mimicking the complex viral membrane. Our results indicate that the lipid environment heavily affects the dynamics and association of the transmembrane helices, modulating its structure. In addition, we have investigated the effect of the cytoplasmic tail (CT). Unexpectedly, this region has a tremendous effect on the lateral organization of the transmembrane. These results clearly highlights the importance of this region in the overall structure of the Env protein and point towards its key role for the in-silico design of effective vaccines towards this domain.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2025

Enhanced Production of Algae Lipids and Carbohydrates for Fuel and Polyurethane Precursors

This Final Technical Report summarizes the goals, approach, and outcomes of the project “Enhanced Production of Algae Lipids and Carbohydrates for Fuel and Polyurethane Precursors”. The project addressed the challenge of improving microalgae biomass productivity and simultaneously producing valuable polyurethane precursors (PUPs), from both lipids and carbohydrates, that can be converted into renewable biofuels and bio-based polyurethane (PU) products. By integrating advanced genetic engineering, traditional breeding, high-throughput screening, pilot cultivation, and chemical conversion technologies, the team achieved significant advancements in algae biotechnology.

09 BIOMASS FUELS↗
DOE OSTI2022

Synthesis of Hydrophilic Derivative Surfactants From Algae-Derived Unsaponifiable Lipids

In the context of decarbonizing the economy, the utilization of biologically sourced feedstocks to produce replacements for petroleum-derived materials is becoming more urgent. Improving renewable biomass production and utilization is imperative for commercializing future biorefineries. Algae-derived biomass is a particularly promising feedstock thanks to its attractive oil content and composition; specifically, the high-value products in the unsaponifiable lipids have not been included in a conversion process. Here we demonstrate surfactant synthesis from a complex oil fraction as the hydrophobic donor moieties, yielding products that are similar to commercially available surfactants such as the linear alkyl benzene sulfonates. Unsaponifiable lipids extracted from algae were derivatized to non-ionic surfactants using a green chemical synthesis route based on a double esterification with succinic acid and polyethylene glycol. The in-depth molecular and structural surfactant characterization is included and indicates that the resulting properties fall between those of pure cholesterol and phytol used as surrogates for the reaction synthesis demonstration. This is the first demonstration of an effective and potentially high-value synthesis of functional surfactants with properties that can be tailored based on the relative composition of the resulting hydrocarbon alcohol components in the mixture. This novel green chemistry synthesis approach provides a route to high-value product synthesis from algae.

09 BIOMASS FUELS↗
DOE OSTI2023

Membrane lipid and expression responses of Saccharolobus islandicus REY15A to acid and cold stress

Archaea adjust the number of cyclopentane rings in their glycerol dibiphytanyl glycerol tetraether (GDGT) membrane lipids as a homeostatic response to environmental stressors such as temperature, pH, and energy availability shifts. However, archaeal expression patterns that correspond with changes in GDGT composition are less understood. Here we characterize the acid and cold stress responses of the thermoacidophilic crenarchaeon Saccharolobus islandicus REY15A using growth rates, core GDGT lipid profiles, transcriptomics and proteomics. We show that both stressors result in impaired growth, lower average GDGT cyclization, and differences in gene and protein expression. Transcription data revealed differential expression of the GDGT ring synthase grsB in response to both acid stress and cold stress. Although the GDGT ring synthase encoded by grsB forms highly cyclized GDGTs with ≥5 ring moieties, S. islandicus grsB upregulation under acidic pH conditions did not correspond with increased abundances of highly cyclized GDGTs. Our observations highlight the inability to predict GDGT changes from transcription data alone. Broader analysis of transcriptomic data revealed that S. islandicus differentially expresses many of the same transcripts in response to both acid and cold stress. These included upregulation of several biosynthetic pathways and downregulation of oxidative phosphorylation and motility. Transcript responses specific to either of the two stressors tested here included upregulation of genes related to proton pumping and molecular turnover in acid stress conditions and upregulation of transposases in cold stress conditions. Overall, our study provides a comprehensive understanding of the GDGT modifications and differential expression characteristic of the acid stress and cold stress responses in S. islandicus.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2023

Aggregating in vitro-grown adipocytes to produce macroscale cell-cultured fat tissue with tunable lipid compositions for food applications

We present a method of producing bulk cell-cultured fat tissue for food applications. Mass transport limitations (nutrients, oxygen, waste diffusion) of macroscale 3D tissue culture are circumvented by initially culturing murine or porcine adipocytes in 2D, after which bulk fat tissue is produced by mechanically harvesting and aggregating the lipid-filled adipocytes into 3D constructs using alginate or transglutaminase binders. The 3D fat tissues were visually similar to fat tissue harvested from animals, with matching textures based on uniaxial compression tests. The mechanical properties of cultured fat tissues were based on binder choice and concentration, and changes in the fatty acid compositions of cellular triacylglyceride and phospholipids were observed after lipid supplementation (soybean oil) during in vitro culture. This approach of aggregating individual adipocytes into a bulk 3D tissue provides a scalable and versatile strategy to produce cultured fat tissue for food-related applications, thereby addressing a key obstacle in cultivated meat production.

Yuen Jr, John Se Kit (ORCID:0000000198541654)↗
NASA NTRS1977

Lipid extraction from isolated single nerve cells

A method of extracting lipids from single neurons isolated from lyophilized tissue is described. The method permits the simultaneous extraction of lipids from 30-40 nerve cells and for each cell provides equal conditions of solvent removal at the conclusion of extraction.

Krasnov, I. V.↗