• 한국식품과학회지
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• 제20권3호
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• pp.441-446
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• 1988

마른 멸치를$0{\sim}0.5N$의 NaOH 용액과 함께 마쇄한 뒤 $60^{\circ}C$에서 $0{\sim}6$시간까지 처리시키면서 원심분리 하여 얻어진 멸치 추출액의 고형분 수율과 몇몇 물리적 품질과 관능적 품질의 변화를 측정하였다. 그 결과 NaOH의 농도와 처리시간이 증가 할수록 고형분과 단백질의 수율은 증가하였으며 고유점도는 급격히 증가하여 최고 값에 도달하였다가 서서히 감소하였다. Hunter값으로 표시된 추출액의 색의 변화는 'L'값이 반응초기에 증가하여 색이 밝아졌다가 그 후 강소하였으며 'a'값과 'b'값은 약간 증가하는 경향을 보여 주었다. 알칼리 처리가 멸치추출액의 맛과 냄새에 미치는 영향은 알칼리 농도와 처리시간이 가할수록 맛과 냄새의 강도가 현저히 상승 하였으며 맛과 냄새 중 소라맛, 쓴맛 그리고 소라냄새, 바닷물 냄새에서 특히 높은 강도를 보여 주었다.

• 한국축산식품학회지
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• 제37권1호
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• pp.134-138
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• 2017

Salmonella enterica infects a broad range of host animals, and zoonostic infection threatens both public health and the livestock and meat processing industries. Many antimicrobials have been developed to target Salmonella envelope that performs essential bacterial functions; however, there are very few analytical methods that can be used to validate the efficacy of these antimicrobials. In this study, to develop a potential biosensor for Salmonella envelope stress, we examined the transcription of the S. enterica serovar typhimurium spy gene, the ortholog of which in Escherichia coli encodes Spy (${\underline{s}}pheroplast$ ${\underline{p}}rotein$ ${\underline{y}}$). Spy is a chaperone protein expressed and localized in the periplasm of E. coli during spheroplast formation, or by exposure to protein denaturing conditions. spy expression in S. typhimurium was examined by constructing a spy-gfp transcriptional fusion. S. typhimurium spy transcription was strongly induced during spheroplast formation, and also when exposed to membrane-disrupting agents, including ethanol and the antimicrobial peptide polymyxin B. Moreover, spy induction required the activity of regulator proteins BaeR and CpxR, which are part of the major envelope stress response systems BaeS/BaeR and CpxA/CpxR, respectively. Results suggest that monitoring spy transcription may be useful to determine whether a molecule particularly cause envelope stress in Salmonella.

• 한국환경성돌연변이발암원학회:학술대회논문집
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• 한국환경성돌연변이발암원학회 2002년도 Current Trends in Toxicological Sciences
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• pp.25-35
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• 2002

Transcription factor Nrf2 is essential for the antioxidant responsive element (ARE)-mediated induction of phase II detoxifying and oxidative stress enzyme genes. Detailed analysis of differential Nrf2 activity displayed in transfected cell lines ultimately led to the identification of a new protein, which we named Keap1, that suppresses Nrf2 transcriptional activity by specific binding to its evolutionarily conserved amino-terminal regulatory domain. The closest homolog of Keap1 is a Drosophila actin-binding protein called Kelch, implying that Keap1 might be a Nrf2 cytoplasmic effector. We then showed that electrophilic agents antagonize Keap1 inhibition of Nrf2 activity in vivo, allowing Nrf2 to traverse from the cytoplasm to the nucleus and potentiate the ARE response. We postulate that Keap1 and Nrf2 constitute a crucial cellular sensor for oxidative stress, and together mediate a key step in the signaling pathway that leads to transcriptional activation by this novel Nrf2 nuclear shuttling mechanism. The activation of Nrf2 leads in turn to the induction of phase II enzyme and antioxidative stress genes in response to electrophiles and reactive oxygen species.

• Applied Biological Chemistry
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• 제49권3호
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• pp.254-258
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• 2006

내분비계장애물질에 노출된 어류의 에스트로겐 활성에 대한 생물지표단백질인 vitellogenin을 검출하는 압전류적 면역센서를 잉어 vitellogenin에 대한 항체와 AT-cut 수정진동자를 생물요소와 변환기로 사용하여 구성하고 이를 이용한 잉어 vitellogenin 검출을 행하였다. 이형이기능성의 티올화 가교화제인 sulfosuccinimidyl 6-[3-(2-pyridyldithio)propionamido]hexanoate 처리에 의하여 티올화된 항체를 수정진동자상의 금전극에 화학흡착법에 의하여 고정화하여 센서 chip을 제조하였다. 센서반응을 위한 반응완충용액을 0.1M sodium phosphate(pH 7.4)로 선정한 후 $0.4864{\sim}486.4000\;nM$의 vitellogenin 용액을 가하였을 때 농도의존적인 센서반응의 증가가 나타났으며 이 때 잉어 vitellogenin에 대한 검출한계는 0.4864 nM로 추정되었다.

• 한국콘텐츠학회논문지
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• 제21권4호
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• pp.825-832
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• 2021

본 연구는 치주질환의 주 원인균인 P. gingivalis에 선택적으로 작용하는 특이적 앱타머를 선별하고 선별된 앱타머와 결합하는 단백질 분자를 정제 및 동정함으로써 P. gingivalis에 관한 작용기전을 규명하고자 하였다. 이를 위하여 39개의 random sequence를 갖는 DNA library를 제조하여 SELEX 방법을 이용하여 P. gingivalis에 특이성을 가진 앱타머를 선별하였으며 PCR2.1 cloning vector를 활용한 cloning을 시행하여 염기서열을 분석했다. 8종의 각기 다른 염기서열을 가진 앱타머를 선별하였고 직접적으로 작용하는 단백질을 밝혀내고자 선별된 앱타머 중 APG-3를 이용하여 modified weston blot을 시행하고 단백질을 분석한 결과 P. gingivalis에 선택적으로 결합하는 11종의 단백질을 분리, 동정하였다. 이와 같은 결과로 앱타머가 치주질환의 원인균인 P. gingivalis의 당 대사 및 세포활성억제와 관련된 단백질에 선택적으로 결합하여 부착함으로써 치주질환의 진단을 위한 센서로 가능성을 제시했다.

• 한국미생물·생명공학회지
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• 제48권1호
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• pp.24-31
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• 2020

Five genes (mxbDM, mxcQE and mxaB) are responsible for the transcription of methanol oxidation genes in Methylobacterium strains. Among these, MxbDM and MxcQE constitute the two-component system (TCS) regulating methanol metabolism. In this study, we integrated the methanol-sensing domain of MxbD and MxcQ with the EnvZ/OmpR from Escherichia coli. The domain-swapping strategy resulted in chimeric histidine kinases (HK's) MxbDZ and MxcQZ AM1 containing recombinant E. coli. Real-time quantitative PCR was used to monitor OmpC expression mediated by the chimeric HK and response regulator (RR) OmpR. Further, an ompC promoter based fluorescent biosensor for sensing methanol was developed. GFP fluorescence was studied both qualitatively and quantitatively in response to environmental methanol. GFP measurement also confirmed ompC expression. Maximum fluorescence was observed at 0.05% methanol and 0.01% methanol using MxbDZ and MxcQZ AM1, respectively. Thus the chimeric HK containing E. coli were found to be highly sensitive to methanol, resulting in a rapid response making them an ideal sensor.

• BMB Reports
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• 제32권3호
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• pp.215-225
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• 1999

Phytochromes (with gene family members phyA, B, C, D, and E) are a wavelength-dependent light sensor or switch for gene regulation that underscore a number of photo responsive developmental and morphogenic processes in plants. Recently, phytochrome-like pigment proteins have also been discovered in prokaryotes, possibly functioning as an auto-phosphorylating/phosphate-relaying two-component signaling system (Yeh et al., 1997). Phytochromes are photochromically convertible between the light sensing Pr and regulatory active Pfr forms. Red light converts Pr to Pfr, the latter having a "switch-on" conformation. The Pfr form triggers signal transduction pathways to the downstream responses including the expression of photosynthetic and other growth-regulating genes. The components involved in and the molecular mechanisms of the light signal transduction pathways are largely unknown, although G-proteins, protein kinases, and secondary messengers such as $Ca^{2+}$ ions and cGMP are implicated. The 124-127 kDa phytochromes form homodimeric structures. The N-terminal half contains the tetrapyrrolic phytochromobilin for red/far-red light absorption. The C-terminal half includes both a dimerization motif and regulatory box where the red light signal perceived by the chromophore-domain is recognized and transduced to initiate the signal transduction cascade. A working model for the inter-domain signal communication within the phytochrome molecule is proposed in this Review.

• BMB Reports
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• 제30권5호
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• pp.308-314
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• 1997

We investigated biotinylation of nitrocellulose membrane for immuno-filtration capture assay. In order to enhance the efficiency of biotinylation, nitrocellulose membranes were pretreated with several chemicals for the purpose of suitable protein absorption through surface modification. As a signal generating enzyme, urease was used and the concentration of avidin was optimized for the efficient binding kinetics between urease-biotin in liquid phase and biotinylated membrane in solid phase. For effective biotinylation, bovine serum albumin-biotin complexes could be immobilized at a concentration of $370\;{\mu}g$/stick ($4.4\;cm^2$). Among tested chemicals, polylysine (0.25%) showed a significant effect in biotinylation. Polylysine is thought to enhance surface area by extending unbound residues into solution. Time of treatment over 30 min and higher molecular weight of polylysines (58,100 dalton) showed positive effect on the enhancement of biotinylation. The result from this study may be useful for developing a new biosensor and other biofunctional membranes for examining molecular recognition.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1545_1546
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• 2009

This paper reports a novel wireless love-wave biosensor on $41^{\circ}$ YX $LiNbO_3$ piezoelectric substrate and $SiO_2$ guiding layer for Immunoglobulin G (IgG) detection by protein binding. Different from the traditional biosensors based on surface acoustic wave (SAW) oscillator structured by delay line/resonators, a 440MHz reflective delay line consists of SPUDTs and three reflectors placed on $41^{\circ}$ YX $LiNbO_3$ in a row was fabricated as the sensor element. Good linearity, reproducibility, and high sensitivity were observed in the IgG concentration range 1~65nM. Unique advantages as high sensitivity, passive and simple measurement system are present over currently available other biosensors.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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• pp.1354-1363
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• 1993

Optical methods were developed to examine their feasibility for quality evaluation of peanut with pod. Surface color and internal quality of peanut were measured without contact. The surface color of peanut was measured by light reflectance at a region of visible wavelengths. Its characteristic was high correlated with a visual grading of peanut. A trial machine for the color grading of peanut was developed using an optical sensor and it was considered to compare with the visual grading. The spectral reflectance at a region of near infrared wavelengths from 1,200 to 2,500nm was measured , and the chemical components of peanut were related to spectral reflectance at special wavelengths. The protein, fat and moisture contents of peanut were estimated by the near infrared methods. An infrared imaging method was developed to evaluate the internal quality of peanut with pod. As thermal characteristic of peanut with pod was deeply related to internal quality , the quality of peanut can be evaluated by temperature changes on the surface of peanut. Measurement of surface color, near infrared reflectance and thermal imaging were shown to be very effective in grading of peanut with pod.