• Journal of Microbiology and Biotechnology
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• v.21 no.12
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• pp.1330-1335
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• 2011

N-Acyl homoserine lactones (AHLs) serve as the vital quorum-sensing signals that regulate the virulence of the pathogenic bacterium Erwinia carotovora. In the present study, an approach to efficiently restrain the pathogenicity of E. carotovora-induced soft rot disease is described. Bacillus thuringiensis-derived N-acyl homoserine lactonase (AiiA) was projected onto the surface of Pseudomonas putida cells, and inoculation with both strains was challenged. The previously identified N-terminal moiety of the ice nucleation protein, InaQ-N, was applied as the anchoring motif. A surface display cassette with inaQ-N/aiiA was constructed and expressed under the control of a constitutive promoter in P. putida AB92019. Surface localization of the fusion protein was confirmed by Western blot analysis, flow cytometry, and immunofluorescence microscopy. The antagonistic activity of P. putida MB116 expressing InaQ-N/AiiA toward E. carotovora ATCC25270 was evaluated by challenge inoculation in potato slices at different ratios. The results revealed a remarkable suppressing effect on E. carotovora infection. The active component was further analyzed using different cell fractions, and the cell surface-projected fusion protein was found to correspond to the suppressing effect.

• Journal of Microbiology and Biotechnology
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• v.30 no.7
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• pp.1097-1103
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• 2020

Bacterial surface display systems have been developed for various applications in biotechnology and industry. Particularly, the discovery and design of anchoring motifs is highly important for the successful display of a target protein or peptide on the surface of bacteria. In this study, an efficient display system on Escherichia coli was developed using novel anchoring motifs designed from the E. coli mipA gene. Using the C-terminal fusion system of an industrial enzyme, Pseudomonas fluorescens lipase, six possible fusion sites, V¹⁴⁰, V¹⁷⁶, K¹⁷⁹, V²²⁶, V²³², and K²³⁴, which were truncated from the C-terminal end of the mipA gene (MV¹⁴⁰, MV¹⁷⁶, MV¹⁷⁹, MV²²⁶, MV²³², and MV²³⁴) were examined. The whole-cell lipase activities showed that MV¹⁴⁰ was the best among the six anchoring motifs. Furthermore, the lipase activity obtained using MV¹⁴⁰ as the anchoring motif was approximately 20-fold higher than that of the previous anchoring motifs FadL and OprF but slightly higher than that of YiaTR232. Western blotting and confocal microscopy further confirmed the localization of the fusion lipase displayed on the E. coli surface using the truncated MV¹⁴⁰. Additionally the MV¹⁴⁰ motif could be used for successfully displaying another industrial enzyme, α-amylase from Bacillus subtilis. These results showed that the fusion proteins using the MV¹⁴⁰ motif had notably high enzyme activities and did not exert any adverse effects on either cell growth or outer membrane integrity. Thus, this study shows that MipA can be used as a novel anchoring motif for more efficient bacterial surface display in the biotechnological and industrial fields.

• Journal of Microbiology and Biotechnology
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• v.20 no.4
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• pp.712-717
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• 2010

Cytochrome P450 enzymes (P450s) are involved in the synthesis of a wide variety of valuable products and in the degradation of numerous toxic compounds. The P450 BM3 (CYP102A1) from Bacillus megaterium was the first P450 discovered to be fused to its redox partner, a mammalian-like diflavin reductase. Here, we report the development of a whole-cell biocatalyst using ice-nucleation protein (Inp) from Pseudomonas syringae to display a hemeand diflavin-containing oxidoreductase, P450 BM3 (a single, 119-kDa polypeptide with domains of both an oxygenase and a reductase) on the surface of Escherichia coli. The surface localization and functionality of the fusion protein containing P450 BM3 were verified by flow cytometry and measurement of enzymatic activities. The results of this study comprise the first report of microbial cell-surface display of a heme- and diflavin-containing enzyme. This system should allow us to select and develop oxidoreductases containing heme and/or flavins into practically useful whole-cell biocatalysts for extensive biotechnological applications, including selective synthesis of new chemicals and pharmaceuticals, bioconversion, bioremediation, live vaccine development, and biochip development.

• Archives of Plastic Surgery
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• v.32 no.3
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• pp.311-313
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• 2005

Generally, many Asian women tend to dislike the square jaw, as they believe it makes the face look wider, giving a stubborn and strong impression. Contouring of the mandible is therefore a relatively common aesthetic procedure among Asians. These days, the use of botulinum toxin for contouring of the lower face offer simple alternative to surgery. Motor point, which is the site over a muscle where its contraction may be elicited by a minimal intensity short duration electrical stimulus, is the optimal injection point of botulinum toxin. Study was undertaken to identify the location of motor point of the masseter muscle and the skin surface landmark. First, the thickest point of the masseter muscle was inspected through palpation and inspection by 3 different individual plastic surgeons and then compound muscle action potentials(CMAPs) of masseter muscle in 15 health volunteers were recorded using EMG. For the localization of the measured points, line between lateral canthus to the mandibular angle was used. Location of motor points were mapped to skin surface from lateral canthus in a percentage of the distance along the landmark line and in distance in millimeters. The clinical injection point was located at 71.69 percentile and 7.3 mm of the landmark line. The motor point test was located at 72.54 percentile and 7.1 mm of the landmark line. The depth of motor point was 16mm. There was no statistically significant difference between the clinical injection point and the motor point. We conclude that surface mapping of motor point of the masseter muscle would increase accessibility and accuracy in botulinum toxin injection for contouring of the lower face.

• Journal of Microbiology and Biotechnology
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• v.34 no.3
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• pp.735-745
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• 2024

Avian influenza is a serious threat to both public health and the poultry industry worldwide. This respiratory virus can be combated by eliciting robust immune responses at the site of infection through mucosal immunization. Recombinant probiotics, specifically lactic acid bacteria, are safe and effective carriers for mucosal vaccines. In this study, we engineered recombinant fusion protein by fusing the hemagglutinin 1 (HA1) subunit of the A/Aquatic bird/Korea/W81/2005 (H5N2) with the Bacillus subtilis poly γ-glutamic acid synthetase A (pgsA) at the surface of Lactobacillus casei (pgsA-HA1/L. casei). Using subcellular fractionation and flow cytometry we confirmed the surface localization of this fusion protein. Mucosal administration of pgsA-HA1/L. casei in mice resulted in significant levels of HA1-specific serum IgG, mucosal IgA and neutralizing antibodies against the H5N2 virus. Additionally, pgsA-HA1/L. casei-induced systemic and local cell-mediated immune responses specific to HA1, as evidenced by an increased number of IFN-γ and IL-4 secreting cells in the spleens and higher levels of IL-4 in the local lymphocyte supernatants. Finally, mice inoculated with pgsA-HA1/L. casei were protected against a 10LD50 dose of the homologous mouse-adapted H5N2 virus. These results suggest that mucosal immunization with L. casei displaying HA1 on its surface could be a potential strategy for developing a mucosal vaccine against other H5 subtype viruses.

• Advances in nano research
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• v.2 no.3
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• pp.157-172
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• 2014

The three-dimensional Nano-Electronic Modeling toolkit (NEMO 3-D) is an open source software package that allows the atomistic calculation of single-particle electronic states and optical response of various semiconductor structures including bulk materials, quantum dots, impurities, quantum wires, quantum wells and nanocrystals containing millions of atoms. This paper, first, describes a software module introduced in the NEMO 3-D toolkit for the calculation of electronic bandstructure and interband optical transitions in nanowires having wurtzite crystal symmetry. The energetics (Hamiltonian) of the quantum system under study is described via the tight-binding (TB) formalism (including $sp^3$, $sp^3s^*$ and $sp^3d^5s^*$ models as appropriate). Emphasis has been given in the treatment of surface atoms that, if left unpassivated, can lead to the creation of energy states within the bandgap of the sample. Furthermore, the developed software has been validated via the calculation of: a) modulation of the energy bandgap and the effective masses in [0001] oriented wurtzite nanowires as compared to the experimentally reported values in bulk structures, and b) the localization of wavefunctions and the optical anisotropy in GaN/AlN disk-in-wire nanowires.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.75-75
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• 2015

Strong interactions between electromagnetic radiation and electrons at metallic interfaces or in metallic nanostructures lead to resonant oscillations called surface plasmon resonance with fascinating properties: light confinement in subwavelength dimensions and enhancement of optical near fields, just to name a few [1,2]. By utilizing the properties enabled by geometry dependent localization of surface plasmons, metal photonics or plasmonics offers a promise of enabling novel photonic components and systems for integrated photonics or sensing applications [3-5]. The versatility of the nanoplasmonic platform is described in this talk on three folds: our findings on an enhanced ultracompact photodetector based on nanoridge plasmonics for photonic integrated circuit applications [3], a colorimetric sensing of miRNA based on a nanoplasmonic core-satellite assembly for label-free and on-chip sensing applications [4], and a controlled fabrication of plasmonic nanostructures on a flexible substrate based on a transfer printing process for ultra-sensitive and noise free flexible bio-sensing applications [5]. For integrated photonics, nanoplasmonics offers interesting opportunities providing the material and dimensional compatibility with ultra-small silicon electronics and the integrative functionality using hybrid photonic and electronic nanostructures. For sensing applications, remarkable changes in scattering colors stemming from a plasmonic coupling effect of gold nanoplasmonic particles have been utilized to demonstrate a detection of microRNAs at the femtomolar level with selectivity. As top-down or bottom-up fabrication of such nanoscale structures is limited to more conventional substrates, we have approached the controlled fabrication of highly ordered nanostructures using a transfer printing of pre-functionalized nanodisks on flexible substrates for more enabling applications of nanoplasmonics.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05d
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• pp.33-37
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• 2003

Endovaginal and endorectal receiver only surface coil were designed for MR imaging(MRI) and $^1H$ MR spectroscopy(MRS) for the uterine cervix and the prostate. The shape of endovaginal coil wire was rectangular with round comer. The shape of endorectal coil wire was long elliptic shape during insertion and circular shape after insertion. Conventional spin echo and fast spin echo sequences were used as T1 and T2 weighted imaging sequences, respectively. 3D volume localized in vivo $^1H$ MR spectroscopy of the human cervix and prostate was performed using PRESS or STEAM localization method. Using home-built endvaginal and endorectal coils, excellent T1 and T2 images were obtained to visualize early cervical and prostate tumors. 3D volume localized in vivo $^1H$ MRS was useful to differentiate the cancerous tissue from the normal tissue.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.7
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• pp.769-776
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• 2011

In order to cope with the requirements of smaller patterns, larger surfaces and lower costs in the fields of displays, optics and energy, greater attentions is now being paid to the development of micro-pattern machining technology. Compared with flat molds, roll molds have the advantages of short delivery, ease of manufacturing larger surfaces, and continuous molding. This paper presents the state-of-the-art of the micro pattern machining technology on the roll molds and introduces some research results on the machining process technology. The copper and nickel-phosphorous-alloy plating process, machining process technology for uniform micro patterns. micro cutting simulation and the real time monitoring system for micro machining are summarized. The developed technologies have led the complete localization of the prism sheets and will be applied to the direct forming process with succeeding research & development.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.5
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• pp.337-346
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• 2008

Applications of nanotechnology in the medical field have provided the fundamentals of tremendous improvement in precise diagnosis and customized therapy. Recent advances in nanomedicine have led to establish a new concept of theragnosis, which utilizes nanomedicines as a therapeutic and diagnostic tool at the same time. The development of high affinity nanoparticles with large surface area and functional groups multiplies diagnostic and therapeutic capacities. Considering the specific conditions related to the disease of individual patient, customized therapy requires the identification of disease target at the cellular and molecular level for reducing side effects and enhancing therapeutic efficiency. Well-designed nanoparticles can minimize unnecessary exposure of cytotoxic drugs and maximize targeted localization of administrated drugs. This review will focus on major pharmaceutical nanomaterials and nanoparticles as key components of designing and surface engineering for targeted theragnostic drug development.