Applicatioin of Nuclear Magnetic Resonance to Protein Structure and Protein-ligand Interation Studies

NMR (Nuclear Magnetic Resonance) has been expanding its application since it was first discovered in the early 50s. In biophysics, it is a very powerful tool complement to X-ray crystallography for protein structure studies. In this dissertation, two different projects studied by two different NMR methods will be presented. In the first part, a membrane protein PLIN1 which resides on the surface of the cellular organelle lipid droplet is investigated by solid-state NMR (ssNMR). It has been shown that PLIN 1 exclusively locates on the surface of lipid droplet and upon phosphorylation, recruits lipase to digest the triglycerides stored in the lipid droplet. However, due to its membrane protein nature, its insolubility resists to crystallization. ssNMR is a perfect tool to study this membrane protein. PLIN1 was reconstituted into DMPG liposomes and multi-dimensional ssNMR spectra were acquired. According to proton spin diffusion data, a membrane interaction model was proposed and later verified by both molecular dynamics (MD) simulation and experimental reconstitution data. In the second part, a soluble protein Mortalin was studied by solution NMR. Mortalin is a heat shock protein 70 (HSP70) family membrane primarily located in the mitochondria. In cancer cells, Mortalin is released to the cytoplasm and forms a complex with p53, sequestering it in the cytoplasm thus inhibiting its translocation to nucleus to induce cell apoptosis. The flexible heteroarotinoid (Flex-Het) SHetA2 with promising anti-cancer activity can bind to Mortalin and release p53 from the complex to induce cell apoptosis. We successfully determined the substrate binding pocket of Mortalin to be the interacting sites with SHetA2 by chemical shift perturbation (CSP). Using AutoDock as the prediction tool, at least two binding configurations of SHetA2 are generated with high binding affinity. According to these results, more SHetA2 analogs were designed and tested in AutoDock. We find that the analogs with longer linkers that can occupy both configurations of SHetA2 yield the highest binding affinity (lowest binding energy). These results will guide future drug designs to increase the efficiency of Flex-Het anti-cancer activity.Physic

Producing a Standard Dataset of Speed Climbing Training Videos Using Deep Learning Techniques

This dissertation presents a methodology for recording speed climbing training sessions with multiple cameras and annotating the videos with relevant data, including body position, hand and foot placement, and timing. The annotated data is then analyzed using deep learning techniques to create a standard dataset of speed climbing training videos. The results demonstrate the potential of the new dataset for improving speed climbing training and research, including identifying areas for improvement, creating personalized training plans, and analyzing the effects of different training methods.The findings will also be applied to the training process of the Jiangxi climbing team through further empirical research to test the findings and further explore the feasibility of this study.Comment: 2023 3rd International Conference on Innovative Talents Training and Sustainable Developmen

Global attractor for a class of nonlinear generalized Kirchhoff models

The paper studies the long time behavior of solutions to the initial boundary value problem(IBVP) for a class of Kirchhoff models flow  .We establish the well-posedness, theexistence of the global attractor in natural energy spac

Complex unit lattice cell for low-emittance storage ring light source

To achieve the true diffraction-limited emittance of a storage ring light source, such as ~10 pm.rad for medium-energy electron beams, within a limited circumference, it is generally necessary to increase the number of bending magnets in a multi-bend achromat (MBA) lattice, as in the future upgrade plan of MAX IV with a 19BA replacing the current 7BA. However, this comes with extremely strong quadrupole and sextupole magnets and very limited space. The former can result in very small vacuum chambers, increasing the coupling impedance and thus enhancing the beam instabilities, and the latter can pose significant challenges in accommodating the necessary diagnostics and vacuum components. Inspired by the hybrid MBA lattice concept, in this paper we propose a new unit lattice concept called the complex unit lattice cell, which can reduce the magnet strengths and also save space. The complex unit cell is numerically studied using a simplified model. Then as an example, a 17BA lattice based on the complex unit cell concept is designed for a 3 GeV storage ring light source with a circumference of 537.6 m, which has a natural emittance of 19.3 pm.rad. This 17BA lattice is also compared with the 17BA lattice designed with conventional unit cells to showcase the benefits of the complex unit cell concept. This 17BA lattice also suggests a new type of MBA lattice, which we call the MBA lattice with semi-distributed chromatic correction

A Comprehensive Analysis of the Downregulation of miRNA-1827 and Its Prognostic Significance by Targeting SPTBN2 and BCL2L1 in Ovarian Cancer

Background: Previous studies demonstrated that miRNA-1827 could repress various cancers on proliferation, angiogenesis, and metastasis. However, little attention has been paid to its role in ovarian cancer as a novel biomarker or intervention target, especially its clinical significance and underlying regulatory network.Methods: A meta-analysis of six microarrays was adopted here to determine the expression trend of miRNA-1827, and was further validated by gene expression profile data and cellular experiments. We explored the functional annotations through enrichment analysis for the differentially expressed genes targeted by miRNA-1827. Subsequently, we identified two hub genes, SPTBN2 and BCL2L1, based on interaction analysis using two online archive tools, miRWALK (it consolidates the resources of 12 miRNA-focused servers) and Gene Expression Profiling Interactive Analysis (GEPIA). Finally, we validated their characteristics and clinical significance in ovarian cancer.Results: The comprehensive meta-analysis revealed that miRNA-1827 was markedly downregulated in clinical and cellular specimens. Transfection of the miRNA-1827 mimic could significantly inhibit cellular proliferation. Concerning its target genes, they were involved in diverse biological processes related to tumorigenesis, such as cell proliferation, migration, and the apoptosis signaling pathway. Moreover, interaction analysis proved that two hub genes, SPTBN2 and BCL2L1, were highly associated with poor prognosis in ovarian cancer.Conclusion: These integrated bioinformatic analyses indicated that miRNA-1827 was dramatically downregulated in ovarian cancer as a tumor suppressor. The upregulation of its downstream modulators, SPTBN2 and BCL2L1, was associated with an unfavorable prognosis. Thus, the present study has identified miRNA-1827 as a potential intervention target for ovarian cancer based on our bioinformatic analysis processes

Optical Interference Coatings

NRC publication: Ye