• BMB Reports
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• 제29권5호
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• pp.398-404
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• 1996

Light-chilling effects were investigated in chilling-sensitive cucumber (Cucumis sativus L. cv. Ilmichungjang) and chilling-resistant pea (Pisum sativum L. cv. Giant) leaf discs in relation to possible damage in D1 protein. In both plants, dark-chilling did not cause any noticeable changes in (Fv)m/Fm and lincomycin did not affect the decrease in (Fv)m/Fm caused by light-chilling. This result suggests that the de novo synthesis of D1 protein did not occur actively during light-chilling. In pea light-chilled for 6 h. the decreased (Fv)m/Fm was partly recovered in the dark, and almost complete recovery was observed in the light. In cucumber light-chilled for 3 h. the reduced (Fv)m/Fm decreased further for the initial 2 h recovery process in the light regardless of the treatment of lincomycin and recovered very slowly. In both plant species, the treatment of lincomycin inhibited the recovery process in the light, but did not significantly inhibit the process in the dark. In cucumber leaves pulse-labeled with $[^{35}S]Met$, the labeled band intensities of isolated pigment-protein complexes were almost the same during the 6 h light-chilling, but significant decreases in band intensities were observed during the 3 h recovery period. This result suggests that the irreversibly damaged D1 protein was degraded during the recovery period. However, no noticeable changes were observed in the pea leaves during the 12 h chilling and 3 h recovery period. The polyacrylamide gel electrophoresis of the pigment-protein complexes showed that the principal lesion sites of light-chilling were different from those of room temperature photoinhibition.

• Bulletin of the Korean Chemical Society
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• 제35권3호
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• pp.858-864
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• 2014

Recently, many researches have shown that even photosynthetic light-harvesting pigment-protein complexes can have quantum coherence in their excitonic energy transfer at cryogenic and physiological temperatures. Because the protein supplies such noisy environment around pigments that conventional wisdom expects very short lived quantum coherence, elucidating the mechanism and searching for an applicability of the coherence have become an interesting topic in both experiment and theory. We have previously studied the quantum coherence of a phycocyanin 645 complex in a marine algae harvesting light system, using Poisson mapping bracket equation (PBME). PBME is one of the applicable methods for solving quantum-classical Liouville equation, for following the dynamics of such pigment-protein complexes. However, it may suffer from many defects mostly from mapping quantum degrees of freedom into classical ones. To make improvements against such defects, benchmarking targets with more accurately described dynamics is highly needed. Here, we fall back to reduced hierarchical equation of motion (HEOM), for such a purpose. Even though HEOM is known to applicable only to simplified system that is coupled to a set of harmonic oscillators, it can provide ultimate accuracy within the regime of quantum-classical description, thus providing perfect benchmark targets for certain systems. We compare the evolution of the density matrix of pigment excited states by HEOM against the PBME results at physiological temperature, and observe more sophisticated changes of density matrix elements from HEOM. In PBME, the population of states with intermediate energies display only monotonically increasing behaviors. Most importantly, PBME suffers a serious issue of wrong population in the long time limit, likely generated by the zero-point energy leaking problem. Future prospects for developments are briefly discussed as a concluding remark.

• Journal of Photoscience
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• 제9권2호
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• pp.314-316
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• 2002

In halobacterial membrane, pharaonis phoborhodopsin (or pharaonis sensory rhdopsin II, psRII) forms a complex with its transducer pHtrII. Flash-photolyis of D75N mutant did not yield M-intermediate but an O-like intermediate is observed. We examined the interaction between D75N of ppR and t-Htr (truncated pHtrII). These formed a complex in the presence of n-dodecyl-$\beta$-D-maltoside, and the association accelerated the decay of the 0 of D75N from 15 to 56 s$\^$-1/. From the decay time constants under varying ratios of D75N and t-Htr, n, the molar ratio of D75N/t-Htr in the complex, and K$\_$D/, the dissociation constant, were estimated. The value of n was unity and K$\_$D/ was estimated to 146 nM. This K$\_$D/ value can be considered as the association between the photo-intermediate and t-Htr, which is deduced by the method of estimation. Previously we (Photochem. Photobiol. 74, 489-494 (2001)) reported K$\_$D/ of 15 $\mu$M for the interaction between the wild-type and t-Htr by means of the change of M-decay rates. Therefore, this value should be the K$\_$D/ value for the interaction between M of the wild-type and t-Htr.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2012년도 춘계학술논문집 1부
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• pp.182-186
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• 2012

human tyrosinase (hTyr) catalyzes first and the rate limiting step in the synthesis of polymerized pigment, melanin which determines skin, hair and eye colors. Mutation of hTyr often brings about decrease of melanin production and further albinism. Meanwhile, a number of cosmetic companies providing skincare products for woman in Asia-Pacific region have tried to develop inhibitors to bright skin color for several decades. In this study, we built a 3D structure by comparative modeling technique based on the crystal structure of tyrosinase from bacillus megaterium as a template to serve structural information of hTyr. According to our model and sequence analysis of type 3 copper protein family proteins, two copper atoms of active site located deep inside are coordinated with six strictly conserved histidine residues coming from four-helix-bundle. Cavity which accommodates substrates was like funnel shape of which entrance was wide and expose to solvent. In addition, protein-substrate and protein-inhibitor complex were modeled with the guide of van der waals surface generated by in house software. Our model suggested that only phenol group or its analogs can fill the binding site near nuclear copper center because inside of binding site has narrow shape relatively. In conclusion, the results of this study may provide helpful information for designing and screening new anti-melanogensis agents.

• Rapid Communication in Photoscience
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• 제2권1호
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• pp.18-23
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• 2013

The photosystem II (PSII) light harvesting complex (LHC) consists of a variety of pigment protein complexes which are involved in structural organization and regulation of photosynthetic unit. These LHC proteins encoded by a group of Lhcb genes are essential for the structural integrity of PSII supercomplex, the channeling the excitation energy to the reaction center of PSII and its redistribution to photosystem I by state transitions. Numerous studies with the help of recent technological advancements have enabled a significant progress in our understanding on the structure of PSII-LHCII supercomplexes and their mobilization under various light conditions. Here, we present a mini-review on the latest concepts and models depicting the structure of PSII-LHCII supercomplexes and the role of Lhcb proteins in their supra-molecular organization. Also we will review on the current understandings and remaining problems involved in the mobilization of the supercomplexes during state transitions and during high light illumination for controlling light energy distribution between the two photosystems.

• 한국수산과학회지
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• 제19권5호
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• pp.493-501
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• 1986

단백질의 어떠한 가열변성 정도에서 소화율 저하에 영향을 미치는 lipid-protein complex가 가장 많이 형성되는 가를 구명하기 위하여 도다리(Pleuronichthys cornutus) 육단백질을 가열변성시키고 four-enzyme system을 이용하여 in vitro digestibility를 측정하였으며, 여기에 도다리 육에서 추출한 지질을 첨가하여 lipid-protein complex가 형성되는 현상을 조사한 결과는 다음과 같다. In vitro digestibility는 5분간 자숙하였을 때 생시료가 $88.09\%$, 탈지시료가 $90.56%$이었으며, 40분 후에는 각각 $85.95\%,\;86.17\%$를 나타내었다. Microwaving의 경우 1분 가열 후의 소화율은 생시료가 $87.41%$, 탈지시료는 $91.47\%$이었고, 7분 가열 후에는 $3{\sim}4\%$ 정도가 감소하였다. lipid-protein complex 생성에 기인된 것으로 생각되는 trypsin indigestible substrates(TIS)는 가열시간, 첨가되는 지질의 양, 상호작용시간에 따라 증가하는 경향을 나타내었다. 도다리 육에서 추출한 지질의 주요 지방산은 $C_{16:0},\;C_{16:1},\;C_{18:1},\;C_{20:5},\;C_{22:6}$이었고, 가열시간에 따른 지방산 조성의 변화는 거의 없었으며. 불포화지방산의 함량이 $67\%$ 정도를 차지하였다. POV, COV의 증가와 함께 갈변물질의 생성이 증가하였고, 단백질 용해도는 microwaving하였을 때 가장 낮았다($19.l9\%$). lipid-protein 상호작용에서 지질의 함량이나 산화정도가 효소적 소화에 가장 큰 저해인자로 작용하였으며, 생시료 및 탈지시료에 지질을 섞어 가열처리하면서 반응시킨 것과 단백질을 가열변성시킨 후 지질을 첨가하여 반응시킨 것을 비교하면 lipid-protein 상호작용으로 인하여 전자가 후자보다 낮은 소화율을 나타내어 단백질과 지질의 상호작용은 단백질 변성현상과 동시에 일어날 가능성이 높음을 알 수 있었다.

• Journal of Photoscience
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• 제9권2호
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• pp.350-352
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• 2002

We examined the bacteriochlorophyill/bacteriopheophytin ratios in several species of purple bacteria containing only LHI. The pigment ratios depended greatly on species. Further, Rhodospirillum rubrum showed wide variation when grown under different light intensity, and Rhodobium marinum showed significant variation from culture to culture even under the same light conditions. The protein ratios of a/RC and $\beta$/RC estimated by SDS-PAGE of chromatophores of Rsp. rubrum and Rbi. marinum exhibited the ratio of $\beta$/$\alpha$ > 1. These findings gave us the novel idea that there are two types of LHl; one is a C-shaped open antenna composed by $\alpha$$\beta$ units surrounding a RC, and another is a small closed ring antenna composed by $\alpha$$\beta$ units located peripherally in a variable ratio to the core complex like LH2.

• 한국가금학회지
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• 제27권2호
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• pp.133-153
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• 2000

The egg's interior quality is one of the most important criteria for commercial producers and consumers. Internal quality is complex, including aesthetic factors such as taste, freshness, nutritional and processing values, and the genetic influences upon these upon these factors ranges from none to considerable. The rate of cholesterol synthesis in the hen is very high compared to other animals and humans. Genetic selection, diet drugs and other chemicals can alter cholesterol concentration in the plasma of laying hen, but attempts to manipulate the cholesterol concentration in the egg yolk are generally unsuccessful since the cholesterol can only be changed to a small extent. Factors which may affect the degree of pigmentation of the yolk include the type of xanthophyll and its concentration in the feed, the feed composition, and the health of the hen. Several feed ingredients interact with carotenoid pigment to improve or reduce their deposition rates in yolks. Egg weight is determined by genetics, body size prior to first egg housing density, environmental temperature, lighting program, total feed consumption, calcium, phosphorus, niacin, water, methionine, total sulfur amino acids, energy, linoleic acid, fat and protein levels. Eggs need to be promote levels. Eggs need to be promoted a versatile commodity and new processed egg items need to be developed. Organic eggs are laid by hens which were raised in chemical and drug frdd environments. There are still difficulties in producing these eggs due to the availability of organic poultry feeds and cost of organic grains.

• Journal of Plant Biotechnology
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• 제50권
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• pp.1-10
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• 2023

고구마(Ipomoea batatas L. Lam)는 영양소, 가공 식품, 동물 사료 및 색소 재료의 유용한 공급원으로 이용 가능한 경제적으로 중요한 대표적인 뿌리 작물이다. 일반적으로 고구마의 저장 뿌리는 수확 후 저장 기간 동안 다양한 미생물과 질병에 의한 부패에 노출되기 쉽다. 수확 후 큐어링은 저장기간 동안 상처를 치유하고 미생물에 의한 부패를 방지하기 위한 가장 적합한 수단으로 알려져 있다. 본 연구에서는 큐어링과 연관된 분자적 기작에 관여하는 단백질들을 확인하기 위해, 큐어링 처리 후 저장기간 동안 단백질체의 변화를 분석하였다. 33℃ (큐어링) 및 15℃ (대조군)에서 3일 동안 처리하고 8주의 저장 기간이 지난 후 2D 전기영동 분석을 통해 단백질 spot의 변화를 확인한 결과, 31개 단백질 spot의 발현량이 차이 나는 것을 확인하였으며, 이들 중 15개의 단백질 spot을 동정하여 그 특성을 분석하였다. 동정된 단백질 중 alphaamylase (spot 1)는 큐어링 처리구에서만 발현량이 증가하였으며, probable aldo-keto reductase 2-like (spot 3) 및 hypothetical protein CHGG_01724 (spot 4)는 큐어링 및 대조구에서 동시에 발현량이 증가하였으나, sporamin A (spot 10)는 큐어링 및 대조구에서 발현량이 감소하였다. 한편, 대조구에서 enolase (spot 14)는 발현량이 증가하였으나, chain A of actinidin-E-64 complex+ (spot 19), ascorbate peroxidase (spot 22) 및 여러 sporamin 단백질들(spot 20, 21, 23, 24, 27, 29, 30 및 31)은 발현량이 감소하였다. 본 연구의 결과는 고구마 저장 뿌리에서 큐어링 처리와 관련된 단백질의 동정 및 수확 후 저장 기간동안 병 저항성과 관련된 기작에 대한 이해를 높이며, 향후 저온 저장 능력이 향상된 신품종 개발을 위한 후보 유전자의 도출에도 기여할 수 있을 것이다.