Structural and functional studies of CARP and titin N2A protein complexes involved in the stress-response of muscle to apoptotic stimuli

The cardiac ankyrin repeat protein (CARP) has been reported to bind to the N2A region of the giant sarcomeric protein titin. The interaction allegedly plays a role in preventing cardiomyocyte apoptosis, thereby protecting against heart failure (HF). The latter is now a leading cause of mortality in the developed world. In this work, we focus on CARP to guide future functional studies that can clarify its significance in heart disease

X-Ray Diffraction Analysis Of Gallium Oxide Thin Films Synthesized By A Simple And Cost-Effective Method

Wide energy gap beta type gallium oxide (Ga2O3) semiconductor material has attracted many researchers’ interests due its thermal and chemical stability. For synthesising Ga2O3 thin films, sol-gel spin coating is a simple and cost-efficient method, especially for spin coating on cheap substrate such as silicon (Si) substrate. However, little is known about the spin coating growth of the Ga2O3 thin films on Si substrate. In this paper, special attention was paid to the pre-treatment of the Si substrate and the coated layer prior and post spin coating because the uniformity and the quality of the synthesized films are strongly affected by the surface conditions of the substrate/layer. To access the structural and crystallite quality of the deposited Ga2O3, X-ray diffraction measurements were carried out and in-depth analyses using Williamson-Hall and size-strain plots methods were performed. The results show that the crystallite size of the spin coated Ga2O3 on Si is not influenced by the micro strain

Effects Of Dry Oxidation Treaments On The Characteristics Of Gallium Oxide Thin Films Prepared Using Sol-Gel Spin Coating Method

In this paper, gallium oxide (Ga2O3) thin films were grown on silicon (Si) substrate using a relatively simple and low-cost sol-gel spin coating method followed dry oxidation process. Two series of dry oxidation experiments were conducted, i.e., (i) annealing at different oxygen flow rates (i.e., from 2 L/min – 5 L/min) under 1100°C, and (ii) annealing at oxygen flow rate of 5 L/min under different temperatures (i.e., from 800°C to 1100°C). The effects of the oxygen gas flow rates under different temperatures on the structural, surface morphology, and optical properties of the deposited films were investigated. All results revealed that crystalline Ga2O3 layers were formed. From the X-ray diffraction results, all deposited films exhibit two prominent diffraction peaks corresponding to the Ga2O3 (1 ̅10) and (002). The annealing at different temperatures experiments showed that the surface roughness and the grains size increased as the temperature increases from 800°C to 1100°C. The optical band gap energy of the deposited films was extracted from the Ultraviolet-violet transmission spectra. This obtained energy bandgap is within the ranges of 4.69 – 4.83 eV, i.e., in reasonable agreement with the reported values. In summary, all the results showed that polycrystalline Ga2O3thin films were able to be grown on p-Si (100) substrate through the proposed methodology. While the best conditions for the dry oxidation process are at the oxygen flowrate of 5 L/min at temperature of 1100o C

Development of Nutrition Literacy Scale for Middle School Students in Chongqing, China: A Cross-Sectional Study

Background: Information on nutrition literacy of middle schoolers is limited and tools for measuring nutrition literacy of middle schoolers are inadequate. Nutrition literacy has a positive effect on health. Improving children's nutrition literacy can help them to master the necessary nutritional knowledge, develop a healthy lifestyle, and learn to supplement nutrition according to their own needs for healthy growth. Objectives: To develop the Chongqing Middle school student Nutrition Literacy Scale (CM-NLS). Methods: Three experiments were conducted. A theoretical framework and an initial item pool of CM-NLS were established based on the literature review. And the two-round Delphi method was used to explore the suitable acceptance indicators and items. Item evaluation and reduction were performed using the classical test theory. Then, the items in the final CM-NLS were tested for their validity and reliability amongst 462 middle school students. The construct validity was assessed using exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). The internal consistency reliability and split-half reliability were evaluated using Cronbach's alpha coefficients. Results: The final CM-NLS consisting of 52 items that were based on three primary items (functional, interactive and critical) and six sub-items (obtain, understand, apply, interact, medial literacy and critical skill) was developed and validated. EFA suggested six factors explaining 69.44% of the total variance (Kaiser–Meyer–Olkin test = 0.916, Bartlett's test χ2 = 5,854.037, P < 0.001). CFA showed that the model fit the data adequately, with χ2/df = 1.911, root mean square error of approximation = 0.063, goodness-of-fit index = 0.822 and adjusted goodness of fit index = 0.790. The total CM-NLS Cronbach's alpha values of internal consistency and split-half reliability were 0.849 and 0.521, respectively, with reasonable reliability. Conclusions: CM-NLS is a valid and reliable instrument for assessing nutrition literacy among middle school students in Chongqing. Specifically, it could be used by practitioners for needs assessment before the implementation of a nutrition education program.This work was supported by the Chinese Nutrition Society (Science Popularization and Communication Research Fund project, Award Number CNS-SCP2020-34)

Molecular Characterisation of Titin N2A and Its Binding of CARP Reveals a Titin/Actin Cross-linking Mechanism

Striated muscle responds to mechanical overload by rapidly up-regulating the expression of the cardiac ankyrin repeat protein, CARP, which then targets the sarcomere by binding to titin N2A in the I-band region. To date, the role of this interaction in the stress response of muscle remains poorly understood. Here, we characterise the molecular structure of the CARP-receptor site in titin (UN2A) and its binding of CARP. We find that titin UN2A contains a central three-helix bundle fold (ca 45 residues in length) that is joined to N- and C-terminal flanking immunoglobulin domains by long, flexible linkers with partial helical content. CARP binds titin by engaging an α-hairpin in the three-helix fold of UN2A, the C-terminal linker sequence, and the BC loop in Ig81, which jointly form a broad binding interface. Mutagenesis showed that the CARP/N2A association withstands sequence variations in titin N2A and we use this information to evaluate 85 human single nucleotide variants. In addition, actin co-sedimentation, co-transfection in C2C12 cells, proteomics on heart lysates, and the mechanical response of CARP-soaked myofibrils imply that CARP induces the cross-linking of titin and actin myofilaments, thereby increasing myofibril stiffness. We conclude that CARP acts as a regulator of force output in the sarcomere that preserves muscle mechanical performance upon overload stress

Association between modes of delivery and postpartum dietary patterns: A cross-sectional study in Northwest China

Objective: Puerperae’ dietary patterns (DPs) during the puerperium may be influenced by the mode of delivery, but population studies on this topic are scarce. This study aims to explore the relationship between DPs and different modes of delivery among puerperae. Methods: A cross-sectional study was conducted on 3,345 parturients in Lanzhou, China. The postpartum food intake was measured by a food frequency questionnaire (FFQ). Factor analysis was used to determine the DPs. Multiple linear regression was employed to examine the association between the mode of delivery and DP. Results: In this study, two DPs, i.e., traditional and modern DPs, were identified. Traditional DP was characterized by high energy-adjusted intake of tubers, coarse cereals, rice, whole grains, fishery products, and eggs. Modern DP included a high intake of coffee, non-sugary drinks, wine, tea, and fishery products. Compared with participants with vaginal delivery (reference category), cesarean section had an inverse association with modern DP (β: −0.11, 95% CI: −0.36, −0.09). A significant interaction was found between education level, monthly household income, alcohol drinking, and modes of delivery. The inverse association between cesarean section and modern DP or the intake of coffee was significant among puerperae with higher or lower monthly household income. However, the inverse association between cesarean section and traditional DP was only found among puerperae with higher monthly household income. Moreover, among the participants with high education, cesarean section was positively associated with intake of vegetables. Conclusion: Cesarean puerperae with higher levels of education and those with lower and higher monthly household income had less unhealthy foods intake than those who had vaginal delivery. They need to be accounted for in educational programs and interventions focused on healthy diet recommendations in puerperium.This project was funded by the Chongqing Social Science Planning Project (2017YBSH057) and joint project of the Ministry of Technology and Ministry of Health (2021MSXM215) and Discipline Cultivation Fund of the First Affiliated Hospital of Chongqing Medical University. The funders had no role in the design, analysis, data interpretation and publication of findings

Scalable, Non-denaturing Purification of Phosphoproteins Using Ga³⁺-IMAC: N2A and M1M2 Titin Components as Study case

The purification of phosphorylated proteins in a folded state and in large enough quantity for biochemical or biophysical analysis remains a challenging task. Here, we develop a new implementation of the method of gallium immobilized metal chromatography (Ga3+-IMAC) as to permit the selective enrichment of phosphoproteins in the milligram scale and under native conditions using automated FPLC instrumentation. We apply this method to the purification of the UN2A and M1M2 components of the muscle protein titin upon being monophosphorylated in vitro by cAMP-dependent protein kinase (PKA). We found that UN2A is phosphorylated by PKA at its C-terminus in residue S9578 and M1M2 is phosphorylated in its interdomain linker sequence at position T32607. We demonstrate that the Ga3+-IMAC method is efficient, economical and suitable for implementation in automated purification pipelines for recombinant proteins. The procedure can be applied both to the selective enrichment and to the removal of phosphoproteins from biochemical samples

Structural and functional studies of CARP/titin-N2A interaction

publishe

Spin Coated Gallium Oxide Thin Films And The Effect Of Mo-Doping Concentration On Luminescence Properties

Beta-type gallium oxide (β-Ga2O3) with ultra-wide band gap energy and good emission property is suitable for optoelectronic applications such as luminescence devices. However, the growth of good quality β-Ga2O3 films using low cost and simple techniques, particularly the sol-gel spin coating technique, is still remains challenging. For luminescence features, undoped and doped β-Ga2O3 emit multicolour emissions due to the multi-energy level of intrinsic vacancies, which is unsuitable for the display application. From the fundamental and engineering point of view, it is worth investigating the above topics. In this project, the β-Ga2O3 thin films synthesized by the sol-gel spin coating method and their photoluminescence were investigated. For the fabrication, the sol-gel spin coating growth conditions, and processes of the β-Ga2O3 thin films on Si and Al2O3 substrates were investigated. Special treatments on the substrate and the coated layer were conducted to improve the uniformity and smoothness of each coated layer and the final deposited film. Different spin coating cycles, and annealing temperatures were also investigated from the morphologic and optical aspects. Finally, a set of samples with 6-layers spin-coated films and annealed under different temperatures, i.e., from 900 °C, to 1100 °C were prepared. These samples were then subjected to an in-depth X-ray diffraction analysis. The results show that the micro strain is not the key factor for the Bragg peaks broadening. To investigate luminescence properties, a series of Mo-doped β-Ga2O3 on Al2O3 were synthesized. A green luminescence band associated with the Mo ion dxz-dyz band transition appeared slowly with the increase of the Mo-doping concentration