Conformational Structure Research Articles

An integration into the diagnostic workflow in a pediatric patient suspected of having Marfan syndrome

BackgroundThe genetic approach to Marfan syndrome (MFS) has evolved over the last few decades, as has our understanding of the variants’ potential structural and functional consequences. It has been proposed that next-generation sequencing be used to improve genetic diagnosis and patient management. To this end, we used a targeted NGS custom panel to perform genetic analysis in a patient with MFS and his or her family members.Case presentationHere, we describe a novel germ-line heterozygous missense variant (transversion c.5371 T > A) found in exon 43 of the FBN1 gene of a patient (proband) with MFS. FBN1 (ENSG0000166147) and TGFB2 (ENSG0000166147) were included in a targeted sequencing panel for MFS (ENSG0000163513). This new variant c.5371 T > A was identified only in the proband, not in unaffected family members or healthy controls.ConclusionsGiven the massive amount of data generated by gene panel analysis, clinical interpretation of genetic variants may become more difficult. As a result, 3D modeling and multidisciplinary approaches should be used in the analysis and annotation of observed variants. The analysis of the protein’s conformational structure in relation to the identified variant could provide useful information. These data can be used to classify observed variants (pathogenic vs non-pathogenic) linked to the MFS phenotype, as well as to track disease progression and potential target treatments.

Conformal structure‐preserving schemes for damped‐driven stochastic nonlinear Schrödinger equation with multiplicative noise

AbstractSince many physical phenomena are often influenced by dispersive medium, energy compensation and random perturbation, exploring the dynamic behaviors of the damped‐driven stochastic system has becoming a hot topic in mathematical physics in recent years. In this paper, inspired by the stochastic conformal structure, we investigate the geometric numerical integrators for the damped‐driven stochastic nonlinear Schrödinger equation with multiplicative noise. To preserve the conformal structures of the system, by using symplectic Euler method, implicit midpoint method and Fourier pseudospectral method, we propose three kinds of stochastic conformal schemes satisfying corresponding discrete stochastic multiconformal‐symplectic conservation laws and discrete global/local charge conservation laws. Numerical experiments illustrate the structure‐preserving properties of the proposed schemes, as well as favorable results over traditional nonconformal schemes, which are consistent with our theoretical analysis.

Molecular Structure, Vibrational Spectrum and Conformational Properties of 4-(4-Tritylphenoxy)phthalonitrile-Precursor for Synthesis of Phthalocyanines with Bulky Substituent.

By DFT method with B3LYP, PBE, CAM-B3LYP, and B97D functionals, it was found that the molecule 4-(4-tritylphenoxy)phthalonitrile (TPPN) has four conformers. The geometric structure, vibrational frequencies, electronic characteristics, and thermodynamic functions of conformers, as well as the structure and energy of transition states, were determined. IR spectrum of TPPN film contains vibrational bands belonging to different conformers. The assignment of bands was performed basing the distribution of normal vibration energy on internal coordinates. A synchronous electron diffraction/mass spectrometric experiment was performed to determine the structure of conformers in a saturated TPPN vapor. The elemental composition of the ions recorded in the mass spectrum indicates the thermal stability of TPPN at least up to T = 200 °C. The difference in the structure of tetrasubstituted metal phthalocyanines, which can be synthesized from different TPPN conformers, has been shown.

A Soft, Fast and Versatile Electrohydraulic Gripper with Capacitive Object Size Detection

AbstractSoft robotic grippers achieve increased versatility and reduced complexity through intelligence embodied in their flexible and conformal structures. The most widely used soft grippers are pneumatically driven; they are simple and effective but require bulky air compressors that limit their application space and external sensors or computationally expensive vision systems for pick verification. In this study, a multi‐material architecture for self‐sensing electrohydraulic bending actuators is presented that enables a new class of highly versatile and reconfigurable soft grippers that are electrically driven and feature capacitive pick verification and object size detection. These electrohydraulic grippers are fast (step input results in finger closure in 50 ms), draw low power (6.5 mW per finger to hold grasp), and can pick a wide variety of objects with simple binary electrical control. Integrated high‐voltage driving electronics are presented that greatly increase the application space of the grippers and make them readily compatible with commercially available robotic arms.

Impacts of the Dynamic High-Pressure Pre-Treatment and Post-Treatment of Whey Protein Aggregates on Their Physicochemical Properties and Emulsifying Activities.

The impacts of dynamic high-pressure (DHP) pretreatment and post-treatment (100 MPa) on the physicochemical and functional properties of whey protein isolate (WPI) aggregates formed by thermal treatment were investigated in this study. When WPI aggregates were formed by thermal treatment, the size of the aggregates formed with the DHP pretreated WPI was smaller than that of the aggregates formed with the original WPI. The size of the WPI aggregates formed by thermal treatment decreased with DHP post-treatment. The conformational parameters (ζ-potential, surface hydrophobicity, and intrinsic fluorescence intensity) of the WPI subjected to DHP pretreatment were not significantly influenced by thermal treatment. However, DHP post-treatment affected these parameters for the WPI aggregates formed during thermal treatment because of dissociation caused by intense shear and cavitation forces during DHP treatment. The emulsifying activity index (EAI) of the WPI aggregates slightly improved with DHP treatment, but its order had little effect on the magnitude of the EAI increase. DHP pretreatment or post-treatment can modulate the conformational structures and the physicochemical properties of protein aggregates.

Computational Evaluation on Molecular Structure, Charge, NMR, Electronic (HOMO-LUMO) Properties, and Spectroscopic Profiling of Pioglitazone with Molecular Docking Studies

The conformational study (PES-Potential Energy Scan) has been performed and a minimum energy conformer structure has been chosen for DFT (Density Functional Theory) exploration on Pioglitazone. Extensive quantum chemical calculations have been carried out to investigate the Fourier Transform Infrared (FTIR), Fourier Transform Raman (FT-RAMAN) investigation have been implemented by emerging DFT calculations based on the B3LYP level with 6-311 ++ G (d, p) basis set, which also helps to provide useful information about the structure of the title compound. The theoretical vibrational wavenumbers are compared with the experimental values. Natural bond orbital analysis has been carried out to explain the charge transfer (or) delocalization of charge due to the intra molecular interactions. NMR has been carried through the same method along with the GIAO method for assigning 1H and 13C chemical shifts. UV–Visible analysis has been done by taking DMSO as a solvent to obtain maximum absorption wavelength. Mulliken atomic charges and Natural population analysis to know electronegative and electropositive atoms in a molecule. Thus, this present study reports the structural, electrical, chemical, and biological activities of Pioglitazone. The molecular docking studies revealed that the title molecule can bind with the protein 1H5U a potential antidiabetic drug. HIGHLIGHTS The stable energy conformer and geometrical parameters were studied Theoretical data acquired using the DFT B3LYP/6–311++G (d,p) basis set was compared to FT-IR, FT-Raman, UV, and NMR results The molecule has a tiny energy gap according to HOMO-LUMO calculations Molecular docking studies suggested that the chemical may be utilized to treat diabetics GRAPHICAL ABSTRACT

Alkaline State of the Domain-Swapped Dimer of Human Cytochrome c: A Conformational Switch for Apoptotic Peroxidase Activity.

A 2.08 Å structure of an alkaline conformer of the domain-swapped dimer of K72A human cytochrome c (Cytc) crystallized at pH 9.9 is presented. In the structure, Lys79 is ligated to the heme. All other domain-swapped dimer structures of Cytc have water bound to this coordination site. Part of Ω-loop D (residues 70-85) forms a flexible linker between the subunits in other Cytc domain-swapped dimer structures but instead converts to a helix in the alkaline conformer of the dimer combining with the C-terminal helix to form two 26-residue helices that bracket both sides of the dimer. The alkaline transition of the K72A human dimer monitored at both 625 nm (high spin heme) and 695 nm (Met80 ligation) yields midpoint pH values of 6.6 and 7.6, respectively, showing that the Met80 → Lys79 and high spin to low spin transitions are distinct. The dimer peroxidase activity increases rapidly below pH 7, suggesting that population of the high spin form of the heme is what promotes peroxidase activity. Comparison of the structures of the alkaline dimer and the neutral pH dimer shows that the neutral pH conformer has a better electrostatic surface for binding to a cardiolipin-containing membrane and provides better access for small molecules to the heme iron. Given that the pH of mitochondrial cristae ranges from 6.9 to 7.2, the alkaline transition of the Cytc dimer could provide a conformational switch to tune the peroxidase activity of Cytc that oxygenates cardiolipin in the early stages of apoptosis.

IAMAP-SCM: A Novel Computational Tool for Large-Scale Identification of Antimalarial Peptides Using Estimated Propensity Scores of Dipeptides.

Antimalarial peptides (AMAPs) varying in length, amino acid composition, charge, conformational structure, hydrophobicity, and amphipathicity reflect their diversity in antimalarial mechanisms. Due to the worldwide major health problem concerning antimicrobial resistance, these peptides possess great therapeutic value owing to their low incidences of drug resistance as compared to conventional antibiotics. Although well-known experimental methods are able to precisely determine the antimalarial activity of peptides, these methods are still time-consuming and costly. Thus, machine learning (ML)-based methods that are capable of identifying AMAPs rapidly by using only sequence information would be beneficial for the high-throughput identification of AMAPs. In this study, we propose the first computational model (termed iAMAP-SCM) for the large-scale identification and characterization of peptides with antimalarial activity by using only sequence information. Specifically, we employed an interpretable scoring card method (SCM) to develop iAMAP-SCM and estimate propensities of 20 amino acids and 400 dipeptides to be AMAPs in a supervised manner. Experimental results showed that iAMAP-SCM could achieve a maximum accuracy and Matthew's coefficient correlation of 0.957 and 0.834, respectively, on the independent test dataset. In addition, SCM-derived propensities of 20 amino acids and selected physicochemical properties were used to provide an understanding of the functional mechanisms of AMAPs. Finally, a user-friendly online computational platform of iAMAP-SCM is publicly available at http://pmlabstack.pythonanywhere.com/iAMAP-SCM. The iAMAP-SCM predictor is anticipated to assist experimental scientists in the high-throughput identification of potential AMAP candidates for the treatment of malaria and other clinical applications.

Graphitic Carbon Nitride Nanostructures as Molecular Modifier for PEDOT:PSS Hole Transport Layer in Polymer Solar Cells

In this article, we introduced graphitic carbon nitride (g-C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> ), a two-dimensional graphene-like material, tuning electronic properties of PEDOT:PSS via secondary doping. The incorporation of g-C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> nanosheets (NS) and quantum dots (QDs) to the aqueous solution of PEDOT:PSS weakens the coulombic interaction between PEDOT and PSS chains, leading to the formation of expanded coil/linear conformational structure. Thereby, increasing the conductivity of doped PEDOT:PSS films by 75% and 30%, respectively, for the optimal doping concentrations of NS and QDs. The polymer solar cell employing these films as hole transport layer (HTL) yielded the power conversion efficiency of 7.65% and 6.44% for NS and QDs, respectively, compared to 5.45% for the reference devices with pristine PEDOT:PSS as HTL. This improvement in photovoltaic performance can be attributed to the increase in short circuit current, carrier mobility, fill factor, and reduced series resistance. The reduced contact barrier, owing to smooth NS and QDs modified HTL, facilitates the charge transport by reducing the overall device resistance by 88% and 30% for NS and QDs, respectively. The modification in the molecular structure of PEDOT:PSS because of the incorporation of NS and QDs resulted in improved device stability retaining almost 40% of the initial PCE even after 200 min of continuous illumination. The results demonstrate a systematic strategy of improving the conductivity and mobility of HTL, resulting in enhanced device performance.

A photopaper‐based low‐cost, wideband wearable antenna for wireless body area network applications

This study presents a low-cost, compact, flexible, and wideband wearable antenna for different wireless body area network (WBAN) band applications, covering medical body area network band of 2.4 GHz, industrial, scientific, and medical band of 2.45 GHz, WiMAX band of 3.5 GHz, and wireless local area network band of 5.2 GHz. The final antenna topology is obtained by hexagonal microstrip radiator patch fabricated on commercially available low-cost photo paper substrate and defected ground plane below the feed line acting as a partial ground to achieve a conformable structure wideband operation. The overall size of the fabricated antenna is 30 × 40 mm2 and yields a wide-bandwidth of 3 GHz (2.30–5.30 GHz), radiation efficiency of 84.35%, and the highest gain of 3.48 dBi at the centre frequency of 5.2 GHz, and minimum gain of 1.91 dBi at 2.45 GHz. Furthermore, our detailed numerical and experimental investigations involving specific absorption rate performance assessment and bending analysis revealed the proposed design's excellent robustness to both human body loading and structural deformation scenarios. Therefore, simulated and measured results strongly advocate that the proposed design has profound implications for flexible and body-worn devices in WBAN applications.

Effect of proanthocyanidins on protein composition, conformational structure, IgE binding capacities and functional properties in soybean protein

This study was performed to determine the crosslinking formed by proanthocyanidins (PC) with respect to IgE binding capacities, functionality, structure and composition of soybean protein (SPI) following the alkali treatment at 60–100 °C. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS–PAGE) showed the formation of >180 kDa polymers, resulting from the formation of SPI-PC conjugates and protein cross-links. Structural analyses demonstrated that SPI-PC conjugates exhibited structural changes to unfold proteins and increase molecular flexibility. Liquid chromatography coupled to tandem mass spectrometry (LC/MS-MS) showed a decrease in unique protein and peptide numbers as well as major allergen and dominant epitopes abundance. When SPI was treated with PC under the alkali treatment at 80 °C, it exhibited a maximum reduction (68.8 %) in the immunoglobulin E (IgE) binding capacity and a maximum increase in DPPH radical scavenging activities (6.11-fold), ABTS + radical scavenging activities (4.80-fold), foaming stability (6.1 %) and emulsifying activity (27.3 %), compared to the control SPI. Overall, this study demonstrates that alkali treatment at 60–100 °C to form SPI-PC conjugates has potential applications for producing hypoallergenic soybean products with the desired functionality, most especially from alkali treatment at 80 °C. Moreover, the addition of PC pronouncedly alleviates the undesirable functional properties in heated SPI.

Dynamics and mechanisms of nonradiative photodissociation of glycine: A theoretical study

Photochemistry of small biomolecules is fundamental to understand the photochemical reactions of larger molecules, such as proteins. In this work, the dynamics and mechanisms of photodissociations of glycine conformers were studied using the DFT, TD-DFT and CASPT2 methods with the aug-cc-pVDZ basis set and microcanonical molecular dynamics simulations with surface hopping dynamics (NVE-MDSH). This study emphasized unimolecular dissociations and isomerization, nonradiative S1 → S0 relaxations that generate molecular products and the interplay between photoenergies and thermal energies. Four nonplanar conformers were suggested by the TD-DFT/B3LYP/aug-cc-pVDZ and CASPT2(8,14)/aug-cc-pVDZ methods to be stable in the S1 state. The potential energy curves obtained from the TD-DFT/B3LYP/aug-cc-pVDZ and CASPT2(8,14)/aug-cc-pVDZ methods and SA-CPMCSCF/6-31G(d) conical intersection optimizations suggested S0/S1 intersections for distorted glycine structures, Cα–N and NH dissociations and NH → OC isomerization. The NVE-MDSH results showed that although no dissociated molecular product was observed in the S1 state, isomerization-mediated dissociation and exothermic S1 → S0 relaxation temperature could lead to eight molecular product channels, in which the vertically excited Wigner-sampled structures generated eleven reactive and stable molecular products in different temperature ranges. These thermally selective reactions favored the lowest energy conformer (structure Ip) as the precursor, from which reactive and stable molecular products were formed above the threshold exothermic relaxation temperature. These theoretical results showed in detail for the first time how unimolecular photodissociations and nonradiative S1 → S0 relaxations create molecules in cold interstellar media without heat transfer from the surroundings. The results in this work could be used in future theoretical and experimental studies on the same or similar systems.

A survey on the stabilizing effect of osmolytes on the ultrasound-irradiated lipase for efficient enzymatic hydrolysis of coconut oil

The stabilizing effect of some osmolytes including betaine, mannitol, proline, sorbitol, and trehalose (each 0.5 M) was investigated on the ultrasound-irradiated (60 kHz and 138 W, for 240 min) lipase by determination of the enzyme half-life time, evaluation of the enzymatic reaction velocity (Vmax), and hydrolysis of coconut oil for production of lauric acid (the main saturated fatty acid of the oil). The enzyme conformational stability was also assessed by circular dichroism (CD) and fluorescence spectroscopy. The average half-life time of mannitol- and sorbitol-treated lipase under the ultrasound irradiation was 511 ± 3 min and 531 ± 2 min, respectively; 3-fold higher than the unirradiated enzyme. The Vmax value of the ultrasound-treated lipase increased from 100 ± 3 nmol min−1 in the absence of osmolyte to 500 ± 7 nmol min−1 and 500 ± 9 nmol min−1 in the presence of mannitol and sorbitol, respectively. CD and fluorescence spectra indicated that mannitol and sorbitol enhanced the rigidity of the lipase molecular conformational structure, increasing the enzyme stability against the ultrasonic field. The ultrasound-irradiated lipase was then used to hydrolyze coconut oil in the absence or presence of the selected osmolytes, which led to liberate 310 ± 6 mg g−1, 413 ± 7 mg g−1, and 420 ± 4 mg g−1 of lauric acid in the absence or presence of sorbitol and mannitol, respectively. In the absence of an ultrasonic field, the non-osmotically-treated lipase was able to liberate only 211 ± 5 mg g−1 of lauric acid. These promising results indicate that sorbitol and mannitol stabilize the structural conformation of lipase under an ultrasonic field which in turn could improve the enzymatic hydrolysis of coconut oil.

Enhanced thermal stability of the β-galactosidase BgaB from Bacillus circulans by cyclization mediated via SpyTag/SpyCatcher interaction and its use in galacto-oligosaccharides synthesis

Cyclization of proteins using SpyTag/SpyCatcher is a novel approach to increase their thermal stability. In this paper, we test this approach on two β-galactosidases from Bacillus circulans, BgaB and BgaC, and find that BgaB was stabilized while BgaC was not. Wild-type BgaB precipitated completely upon heating above 70 °C, but after SpyRing cyclization, it remained soluble after heating to 90 °C. Similarly, wild-type BgaB retained only 50 % activity after heating at 60 °C for 10 min, but this increased to 80 % after SpyRing cyclization. In contrast, cyclization decreased the stability of BgaC. After SpyRing cyclization, BgaC only retained 2 % activity after 20-min incubation at 55 °C, whereas the wild-type BgaC retained 25 % activity. One reason for the different effect of cyclization may the shorter distance between the N- and C-termini in BgaB (20.2 Å) as compared to BgaC (43.7 Å). The intrinsic fluorescence and circular dichroism spectra suggested that SpyRing cyclization of BgaB did not significantly change its conformation or secondary structure. SpyRing cyclized BgaB yielded similar amounts and compositions of galacto-oligosaccharides using a high initial lactose concentration (40 %, w/v), but a slightly higher amount at low initial lactose concentration (5 %, w/v) suggesting increased transgalactosylation activity.

Antioxidant activity analysis of collagen peptide-magnesium chelate

Antioxidant peptides from natural polymer collagen are highly desirable and their ability to coordinate with minerals will provide new leads for the prevention and treatment of oxidative stress-related diseases. Here, we tested the changes of structures and functional properties of bovine bone collagen peptides (BBCP) after magnesium chelation. The Fourier transform infrared (FTIR) results revealed that Mg(II) chelated with BBCP mainly via amino nitrogen and carboxyl oxygen atoms. The fluorescence and circular dichroism (CD) results indicated that Mg(II) could induce and stabilize the conformational structures, and change the amino acid distribution on the surfaces of BBCP. The chelation of BBCP and Mg(II) led to the improvement of radical scavenging activities, and enhanced the intracellular antioxidant enzyme activities and GSH levels, thus demonstrating higher protective and reparative effects against H2O2-induced oxidative damage. This work provides mechanistic insights for further development of peptide-magnesium chelates for oxidative stress mitigation.

Ultrasonic pretreatment improved the physicochemical properties and riboflavin delivery ability of transglutaminase-catalyzed soy protein isolate gel

Soy protein isolate (SPI) was pre-treated with ultrasonic (400 W, 30–120 min) and then formed gel using transglutaminase (TG) method. Effects of ultrasonic pretreatment on structural, rheological and thermal properties as well as riboflavin delivery ability of SPI gel were investigated. Ultrasonic treatment significantly decreased the particle size, increased the free sulfhydryl content, enhanced the surface hydrophobicity, unfolded the conformational structure of SPI, facilitated the disulfide bonds and ε-(γ-glutamyl) lysine isopeptide bonds formation in transglutaminase-catalyzed soy protein isolate gel (TCSG). Ultrasonic pretreatment, particular for 60 min, significantly enhanced the gel strength, storage modulus, loss modulus, consistency and thermal stability, but decreased the flow behavior index of TCSG. The TCSG without ultrasonic pretreatment showed a non-uniform gel network with large and irregular pores. When applied ultrasonic pretreatment, more dense, uniform and stable gel networks were developed. The above physicochemical properties improvements inhibited the swelling behavior and markedly enhanced the riboflavin encapsulation efficiency and riboflavin delivery ability of TCSG, leading to 81% of riboflavin released in simulated intestinal environment. Therefore, ultrasonic pretreatment could be an efficient approach to improving the gel properties and nutrients delivery ability of SPI gel. • Ultrasonic decreased the particle size and increased the free SH content of SPI. • Ultrasonic enhanced the strength, G′, G″, consistency and thermal stability of TCSG. • US-TCSG samples showed more dense, uniform and stable gel networks. • The gel swelling behavior was inhibited and riboflavin delivery ability was enhanced. • 81% of riboflavin was released in simulated intestinal environment.

Characterization of a novel polysaccharide from red ginseng and its ameliorative effect on oxidative stress injury in myocardial ischemia

BackgroundRed ginseng (RG) was widely used as traditional Chinese medicine (TCM) or dietary supplement. However, few researches had been reported on the red ginseng polysaccharide (RGP).MethodsIn this study, a novel heteropolysaccharide named RGP1-1 was fractionated sequentially by DEAE-52 column and Sephadex G-100 gel column. The primary structure of RGP1-1, including glycosyl linkages, molecular weight, monosaccharide composition, morphology and physicochemical property were conducted by nuclear magnetic resonance (NMR), gas chromatography-mass spectrometer (GC–MS), atomic force microscope (AFM), scanning electron microscope (SEM), differential scanning calorimetry-thermogravimetric analysis (DSC-TG) and so on. The effect of RGP1-1 in preventing and treating myocardial ischemia was evaluated by an animal model isoprenaline (ISO) induced mice.ResultsRGP1-1, with a homogeneous molecular weight of 5655 Da, was composed of Glc and Gal in the ratio of 94.26:4.92. The methylation and NMR analysis indicated the backbone was composed of → 1)-Glcp-(4 → and → 1)-Galp-(4 →, branched partially at O-4 with α-D-Glcp-(1 → residue. Morphology and physicochemical property analysis revealed a triple-helical conformation, flaky and irregular spherical structure with molecule aggregations and stable thermal properties of RGP1-1. And it contained 6.82 mV zeta potential, 117.4 nm partical size and polymerization phenomenon. Furthermore, RGP1-1 possessed strong antioxidant activity in vitro and in vivo, RGP1-1 could decrease cardiomyocyte apoptosis and myocardium fibrosis of mice in histopathology and it could decrease significantly the serum levels of cardiac troponin (cTnI), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), malondialdehyde (MDA). Western blot analysis showed that RGP1-1 can increase the expression of main protein Nuclear factor E2-related factor 2(Nrf2), NAD(P)H:quinone oxidoreductase 1 (NQO1), heme oxygenase-1(HO-1) and kelch-like ECH-associated protein1(keap1) in oxidative stress injure progress, and therefore regulate the pathway of Nrf2/HO-1.ConclusionThe above findings indicated that RGP1-1 had an improving effect on ISO-induced myocardial ischemia injury in mice, as novel natural antioxidant and heart-protecting drugs.

Abstract IA015: ASPSCR1-TFE3 reprograms transcription by organizing enhancer loops

Abstract Aberrant transcription in alveolar soft part sarcoma and some Xp11-rearranged renal cell carcinomas is orchestrated by the fusion oncoprotein, ASPSCR1-TFE3, expressed from a t(X;17) chromosomal translocation-mediated fusion gene. Here, proteomic analysis of proteins co-immunoprecipitated with ASPSCR1-TFE3 from human cell lines and mouse genetically-induced tumors revealed strong enrichment of a AAA+ ATPase with known segregase function. Native gel and electron microscopy found that ASPSCR1-TFE3 associates multi-valently with segregase hexamers. Forward and reverse genetic experiments with ASPSCR1-TFE3 and the segregase demonstrated that they function co-dependently for cancer cell proliferation. The presence, hexamer assembly, and enzymatic function of the segregase enabled the transcriptional impact of ASPSCR1-TFE3. The two proteins co-distributed across chromatin genome-wide, associated with enhancers, indicated by flanking H3K27ac enrichment in human cell lines, human tumors, and genetically engineered mouse tumors. These assembled into higher-order chromatin conformation structures demonstrated by HiChIP and downregulated by loss of ASPSCR1-TFE3 or the segregase. Thus, a segregase was found to assemble chromatin into three-dimensional structures as a co-factor of oncogenic transcriptional regulation. Citation Format: Kevin B. Jones. ASPSCR1-TFE3 reprograms transcription by organizing enhancer loops [abstract]. In: Proceedings of the AACR Special Conference: Sarcomas; 2022 May 9-12; Montreal, QC, Canada. Philadelphia (PA): AACR; Clin Cancer Res 2022;28(18_Suppl):Abstract nr IA015.

Co-fermented cow milk protein by Lactobacillus helveticus KLDS 1.8701 and Lactobacillus plantarum KLDS 1.0386 attenuates its allergic immune response in Balb/c mice.

Milk protein is one of the major food allergens. As an effective processing method, fermentation may reduce the potential allergenicity of allergens. This study aimed to evaluate the therapeutic potential of co-fermented milk protein using Lactobacillus helveticus KLDS 1.8701 and Lactobacillus plantarum KLDS 1.0386 in cow milk protein allergy (CMPA) management. This study determined the secondary and tertiary structures of the fermented versus unfermented proteins by Fourier-transform infrared spectroscopy and surface hydrophobicity to evaluate its conformational changes. Our results showed that different fermentation methods have significantly altered the conformational structures of the cow milk protein, especially the tertiary structure. Further, the potential allergenicity of the fermented cow milk protein was assessed in Balb/c mice, and mice treated with the unfermented milk and phosphate-buffered saline were used as a control. We observed a significant reduction in allergenicity via the results of the spleen index, serum total IgE, specific IgE, histamine, and mouse mast cell protease 1 in the mice treated with the co-fermented milk protein. In addition, we analyzed the cytokines and transcription factors expression levels of spleen and jejunum and confirmed that co-fermentation could effectively reduce the sensitization of cow milk protein by regulating the imbalance of T helper (Th1/Th2 and Treg/Th17). This study suggested that changes of conformational structure could reduce the potential sensitization of cow milk protein; thus, fermentation may be a promising strategy for developing a method of hypoallergenic dairy products.

Changes in the structural and catalytic characteristics of α-amylase under moderate electric field

The study aimed to investigate the effect of moderate electric field (MEF) on the performance of α-amylase in corn starch hydrolysis. MEF (1–12.5 V/cm, 50–350 Hz) was performed on α-amylase and/or corn starch under different conditions (0–50 mM Ca 2+ ; 40–70 °C; 10–120 min). As a pretreatment, low-intensity MEF (2.5 V/cm) did not induce the hydrolysis of native and fully gelatinized starch but increased the enzyme activity by 23% due to slight unfolding of α-amylase. Although more extensive hydrolysis was observed for fully gelatinized starch when the hydrolysis was performed by MEF-pretreated α-amylase (reducing sugar: 38.5 g/L, the control; 48.6 g/L, 2.5 V/cm; 51.2 g/L, 2.5 V/cm + 10 mM Ca 2+ ) and MEF treatment in the presence of α-amylase (42.2 g/L, the control; 48.1 g/L, 2.5 V/cm; 51.3 g/L, 2.5 V/cm + 10 mM Ca 2+ ), a small increase occurred for native starch. Overall, the results proved that substrate structure dominated in the enzymatic hydrolysis of starch under MEF, providing a guide for applying electro-based techniques in starch modification. • Low-intensity moderate electric field (MEF) improved the activity of α-amylase. • Enhanced enzyme activity was attributed to the changed conformation structure. • Densely packed structure of starch dominated in MEF-assisted enzymatic hydrolysis. • Extensive hydrolysis occurred for fully gelatinized starch under MEF. • Minor hydrolysis happened for native starch under MEF.