RESUMO
Numerical generation of physical states is essential to all scientific research fields. The role of a numerical generator is not limited to understanding experimental results; it can also be employed to predict or investigate characteristics of uncharted systems. A variational autoencoder model is devised and applied to a magnetic system to generate energetically stable magnetic states with low local deformation. The spin structure stabilization is made possible by taking the explicit magnetic Hamiltonian into account to minimize energy in the training process. A significant advantage of the model is that the generator can create a long-range ordered ground state of spin configuration by increasing the role of stabilization even if the ground states are not necessarily included in the training process. It is expected that the proposed Hamiltonian-guided generative model can bring about great advances in numerical approaches used in various scientific research fields.
RESUMO
Photoelectrical rectifying property of biomolecular heterostructures is investigated in molecular scale. Recombinant ferredoxin and chlorophyll a were used as an electron acceptor and a sensitizer respectively in the molecular layer by mimicking photosynthesis. A self-assembled monolayer of recombinant ferredoxin was formed on Au surface, and then chlorophyll a was deposited onto the recombinant ferredoxin layer by Langmuir-Blodgett method. The formation of recombinant ferredoxin/chlorophyll a hetero-layers was confirmed by the SPR (surface plasmon resonance) spectroscopy, and the surface was observed by the STM (scanning tunneling microscopy). The rectifying property by the STS (scanning-tunneling-spectroscopy) based current-voltage characteristics was achieved in the recombinant ferredoxin/chlorophyll a hetero-layers. Thus, proposed hetero-layers functioned as a rectifier that can be useful property for the development of molecular-scale bioelectronic devices.
Assuntos
Clorofila/química , Ferredoxinas/química , Proteínas Recombinantes/química , Biofísica/métodos , Clorofila A , Eletroquímica/métodos , Escherichia coli/metabolismo , Ouro/química , Microscopia de Tunelamento/métodos , Nanotecnologia/métodos , Fotossíntese , Rhodobacter sphaeroides/metabolismo , Spinacia oleracea/metabolismo , Ressonância de Plasmônio de Superfície/métodos , Propriedades de SuperfícieRESUMO
Complement 1q (C1q) was applied for the specific recognition of antibody-antigen complex in antibody-based protein chip. The specific binding of C1q to antibody-antigen complex was investigated by surface plasmon resonance (SPR) with respect to Yersinia entericolitica, Salmonella typimurium, insulin, and bovine serum albumin. The protein chip was fabricated with two different kinds of antibodies a zigzag configuration. When one of antigens and fluorescein-isothiocyanate (FITC)-labeled C1q was applied on the protein chip, the specific binding event of C1q to immune complexes formed on protein chip was observed by fluorescence microscopy. These results implicate that the C1q can be used as an alternative to many antibodies that may be utilized individually on each spot of the protein chip.
Assuntos
Complexo Antígeno-Anticorpo/análise , Complemento C1q/análise , Complemento C1q/imunologia , Imunoensaio/instrumentação , Análise Serial de Proteínas/instrumentação , Complexo Antígeno-Anticorpo/imunologia , Desenho de Equipamento , Análise de Falha de Equipamento , Imunoensaio/métodos , Análise Serial de Proteínas/métodos , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
We investigated the time-course tumor growth suppression effects of recombinant adenovirus expressing p53 on human cervical cancer cells and cell-specific E7 protein-protein interactions in cell lysates using surface plasmon resonance (SPR) biosensor. Six HPV-infected human cervical cancer cell lines (HPV 16-positive cells, CaSki and SiHa cells; HPV 18-positive cells, HeLa and HeLaS3 cells; and HPV negative C33A and HT3 cells) were used. After infection with AdCMVp53, the cell-specific growth inhibition was studied in vitro and in vivo. Also, we produced the recombinant E7 oncoprotein of HPV 16 type and tested chip-based protein-protein interactions with each cell lysate. For each cervical cancer cell, differential cell growth inhibitions were shown via cell count assay and MTT assay. Note that the same trend in suppression levels was shown in CaSki, HeLa and in SiHa, HeLaS3, respectively. In contrast, infection with AdCMVLacZ showed increased cell growth in a manner similar to the negative control group. The levels of p53 protein were notably expressed in CaSki and HeLa more than in SiHa and HeLaS3 for 4 days. In contrast, p53 expression was continually maintained in C33A and HT3 for 6 days. After transfection AdCMVp53 into CaSki- and SiHa-xenografted nude mice, the size of tumor was remarkably decreased in SiHa cells as compared to AdCMVLacZ transfection. The SPR sensor surface was successfully modified with the recombinant E7 oncoprotein and showed cell-specific interactions between E7 and its target proteins from cell lysates. The anti-tumor effects were accomplished via differential role of p53-specific apoptotic cell death, which is dependent upon the cervical cancer cell line. Also, a molecular level understanding of cell-dependent protein interaction effects of recombinant E7 was shown.
Assuntos
Adenoviridae/genética , Técnicas Biossensoriais/métodos , Proteínas Oncogênicas Virais/metabolismo , Mapeamento de Interação de Proteínas/métodos , Ressonância de Plasmônio de Superfície/métodos , Proteína Supressora de Tumor p53/metabolismo , Neoplasias do Colo do Útero/metabolismo , Neoplasias do Colo do Útero/virologia , Técnicas Biossensoriais/instrumentação , Linhagem Celular Tumoral , Proliferação de Células , Feminino , Terapia Genética/métodos , Humanos , Proteínas E7 de Papillomavirus , Mapeamento de Interação de Proteínas/instrumentação , Ressonância de Plasmônio de Superfície/instrumentação , Transfecção/métodos , Proteína Supressora de Tumor p53/administração & dosagem , Proteína Supressora de Tumor p53/genética , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/terapiaRESUMO
The immobilized cell using self-assembled synthetic oligopeptide was applied to the biological toxicity detection of environmental pollutant. Thin films based on cysteine-terminated synthetic oligopeptides were fabricated for the immobilization of Escherichia coli O157:H7 on gold (Au) substrate. Layer formation and immobilization of E. coli O157:H7 were investigated with surface plasmon resonance (SPR) and atomic force microscopy (AFM). Experimental results showed that the thin film of cysteine-terminated synthetic oligopeptide was successfully fabricated and it could be applied for the immobilization of E. coli O157:H7. The attached living cell was exposed to toxic chemical such as phenol, which induced the change of SPR angle. As the exposed concentration of phenol was increased, the change of plasmon resonance angle was increased, which indicates the decrease of cell viability. The detection limit based on SPR was determined as 5 ppm. The proposed cell immobilization method using self-assembly technique can be applied to construct the cell microarray for the diagnosis, drug detection, and on-site monitoring.
