• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.91-91
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• 2013

Imagine a world where we could biomanufacture hybrid nanomaterials having atomic-scale resolution over functionality and architecture. Toward this vision, a fundamental challenge in materials science is how to design and synthesize protein-like material that can be fully self-assembled and exhibit information-specific process. In an ongoing effort to extend the fundamental understanding of protein structure to non-natural systems, we have designed a class of short peptides to fold like proteins and assemble into defined nanostructures. In this talk, I will talk about new strategies to drive the self-assembled structures designing sequence of peptide. I will also discuss about the specific interaction between proteins and inorganics that can be used for the development of new hybrid solar energy devices. Splitting water into hydrogen and oxygen is one of the promising pathways for solar to energy convertsion and storage system. The oxygen evolution reaction (OER) has been regarded as a major bottleneck in the overall water splitting process due to the slow transfer rate of four electrons and the high activation energy barrier for O-O bond formation. In nature, there is a water oxidation complex (WOC) in photosystem II (PSII) comprised of the earthabundant elements Mn and Ca. The WOC in photosystem II, in the form of a cubical CaMn4O5 cluster, efficiently catalyzes water oxidation under neutral conditions with extremely low overpotential (~160 mV) and a high TOF number. The cluster is stabilized by a surrounding redox-active peptide ligand, and undergo successive changes in oxidation state by PCET (proton-coupled electron transfer) reaction with the peptide ligand. It is fundamental challenge to achieve a level of structural complexity and functionality that rivals that seen in the cubane Mn4CaO5 cluster and surrounding peptide in nature. In this presentation, I will present a new strategy to mimic the natural photosystem. The approach is based on the atomically defined assembly based on the short redox-active peptide sequences. Additionally, I will show a newly identified manganese based compound that is very close to manganese clusters in photosystem II.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.417-424
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• 2019

Despite its superior ability to show distinct cellular morphology and for long-term storage, conventional tissue fixation by formalin has many drawback, including slower fixation, the exposure to harmful chemicals and extensive protein modification. Herein, we assessed the effects of rapid microwave-assisted tissue fixation on histological examination and on protein integrity by comparing these microwave irradiation fixated tissues with the formalin-fixed tissues. One of the paired mouse tissues (liver and kidney) was fixed in formalin and the other was fixed by using microwave irradiation in phosphate buffered saline. Each slide from the paraffin-embedded tissues was examined by H & E staining for the adequacy of fixation and by immunohistochemical staining for antigenicity in a blinded fashion. Evaluation of protein recovery and the protein quality from the fixed tissues were analyzed by the BCA method and Western blotting, respectively. The results from H & E staining and immunohistochemical staining showed that the sections obtained from microwave-fixed tissues under our experimental conditions were comparable to those of the formalin-fixed tissues except for the integrity of RBCs. Furthermore, proteins were effectively extracted from the microwave-fixed tissues with acceptable preservation of the proteins' quality. Taken together, this microwave-assisted tissue processing yields a quick fixation and better protein recovery in higher amounts, as well as the adequacy of fixation and the antigenicity being comparable to formalin-fixed tissues, and this all suggests that this new fixation technique can be applied in an environment where rapid tissue fixation is required.

• Journal of Nutrition and Health
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• v.10 no.2
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• pp.18-26
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• 1977

Among animals, the rabbit is known to be affected most sensitively by dietary changes and to be most susceptible to atherosclerosis. The exact reason is still unknown as to whether the primary cause is intrinsic (tissue itself) or extrinsic such as a blood factor which could be influenced by various dietary means. It is of utmost importance to check the nutritional quality of rabbit meat before it is accepted and adapted as a daily food item. To evaluate nutritional quality of rabbit meat, studies on various aspects of lipid components were carried out in comparison with other animal meats such as beef, pork and chicken also included in the study was the question whether the cooking and storage conditions influence the composition of fatty acids and cholesterol level. Some results and findings are listed below: 1. The content of linoleic acid (18 : 2), one of the essential fatty acids, was much higher in rabbit meat compared to the other meats. The Percentages of this Polyunsaturated fatty acids, was much higher in rabbit meat compared to the other meats. The percentages of this polyunsaturated fatty acid in terms of total fatty acids were $37.3{\pm}3.7$, 5.9, 14.5, and 21.9% for rabbit, beef, pork, and chicken respectively. The degree of unsaturation was high not only in meat but also in liver and adipose tissue of rabbit. The values of iodine number, the indication of degree of unsaturation, were known to be $102{\sim}107$, $32{\sim}47$, $46{\sim}67$, and $55{\sim}77$ for rabbit, beef, pork, and chicken respectively. Such a high proportion of this polyunsaturated fatty acid contained in rabbit meat could be harmful due to their Peroxidation effect. 2. A small amount of lower (short chain) fatty acids was isolated from rabbit tussues, which were not observed in other animal's tissues. The significance of this small amount of short chain fatty acids contained in rabbit meat remained an open question. 3. The concentration of total cholesterol in rabbit meat was similar to that of otherr but the content of esterified cholesterol was higher in rabbit meat. This was probably due to the perference of cholesterol to esterify with unsaturated fatty acids. By roasting the percentage of Polyunsaturated fatty acids was decreased while saturated palmitic acid was proportionally increased. 4 The composition of fatty acids were affected more by dry heat than moist heat. More research should be pursued to improve methods of preservation and storage to prevent possible peroxidation and rancidity problems of rabbit meat. In the meantime, the public should be informed to eat fresh rabbit meat and not to store it for a long period of time. This study was supported by the Ministry of Science and Technology in Korea.

• Applied Biological Chemistry
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• v.36 no.6
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• pp.517-524
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• 1993

To characterize glutelins, the most abundant storage protein in rice, 13 complete coding sequences of glutelin genes from the database were analyzed. According to the phylogenic analysis, these genes could be classified into 5 groups, Group I to V. The degrees of homology were calculated to be in the range of 90 to 60%, but the patterns of hydrophobicity were similar in all the groups. Also, each group was found to have similar amino acid composition with variations in lysine content from 2.5 to 3.6% due to the point mutation of arginine to lysine. The isoelectric points of mature proteins and their basic chains of all the groups showed the value of about 9.0 and 10.0, respectively, while the isoelectric points of acidic chains in these groups showed the distinct value of 6.6, 6.7, 7.2, 8.4 and 7.9. The plot of the fraction of G+C at synonimous site in codons (GC3s) against effective codon numbers suggest no major difference in translational efficiency in the expression of glutelin multigenes.

• Korean journal of applied entomology
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• v.34 no.4
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• pp.287-294
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• 1995

Studies were carried out to elucidate the efficacy of exogeneous 20-hydroxyecdysone treatment on terminating pupal diapause in the fall webworm. Hyphantria cunea Drury. And the difference was also investigated between normal adult development and post-diapause development after 20-hydroxyecdysone treatment. In the diapause termination rate of pupae treated with 20-hydroxyecdysone after storage for various periods at 16L:8D and $25\pm$$1^{\circ}C$, at the highest rate was observed from the group stored for the longest period and the lowest rate from those stored for 1.5 months. The time needed for adult emergence was inversely proportional to the chilling (at $0\pm$$1^{\circ}C$) period, and the longer its exposure period at low temperature, the higher its sensitivity to 20-hydroxyecdysone treatment. Pupal diapause duration was almost the same, regardless of storage period in the total darkness or at the photoperiod of 16L:8D, and also they successfully emerged to adult even without any experience at low temperature. The oxygen consumption rate in normally developing pupae showed nearly a typical U-form. But, that of diapausing pupae treated with 20-hydroxyecdysone slowly increased and jumped 14 days after the treatment. Pupal diapause began before formation of adult tissues, an a timing of adult tissue formation coincided with ascending timing of the metabolic rate in both normally developing pupae and diapausing pupae treated with 20-hydroxyecdysone. The diapausing pupae treated with 20-hydroxyecdysone was similar to normally developing pupae in band patterns of proteins from haemolymph or fat body.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.5
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• pp.409-416
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• 1985

In previous paper (Lee et al., 1983) processing method of sardine meat "surimi" was described as a part of the wort to develop new types of ready-to-cook food materials with dark fleshed fishes. As the other part of the work, processing of low salt mackerel fillet was investigated, in this paper, in which fresh mackerel was filleted, salted in brine or with dry salt for an adequate time until the expected salt concentration reached, washed, air dried (3 m/sec, 15 to $20^{\circ}C$), and finally packed individually in K-flex film bag by vacuum or $N_2$ gas substitution. Salting time and salt concentration of brine was decided by the salt level penetrated into the fillet. As the final salt level was fixed to 4 to $5\%$, salting for 20 hours with $10\%$ dry salt or in $15\%$ brine at $5^{\circ}C$ was enough to get that level of salt. If the final salt level was set 5 to $6\%$, salting for 20-24 hours with $15\%$ dry salt or in $20\%$ brine was adequate. Salt penetration, however, was not much influenced by salting method and temperature. Changes in VBN and salt soluble protein occurred more rapidly in cases of salting with dry salt at $20^{\circ}C$ than salted in brine at $5^{\circ}C$, although it was not significant in the period of 20 to 24 hours. Oxidation of lipid and histamine formation during salting at $20^{\circ}C$ could not be neglected if it was delayed loger than 25 hours. Insolubilizing the salt soluble proteins during the storage of salted fillet occurred rapidly regardless of storage temperature. Browning and histamine formation, however, was depended on temperature and packing condition. In case of air pack, deterioration by browning and rancid was deeply developed but not the case for the packs by vacuum or $N_2$ gas substitution. The shelf-life of the salted mackerel fillet based on panel scores of brown color and rancidity, appeared 21 days for the air packed, and more than 30 days for vacunm or $N_2$ gas packed fillet at $20^{\circ}C$.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.4
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• pp.348-352
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• 1994

Soybean seed consists of two major storage protein, the 7S and 11S globulins. For improving the quality of soybean seed protein, an increase of 11S/7S ratio would be a desirable objective because the 11S globulin contains much more the sulfur-containing amino acids than the 7S globulin. In this study, some soybean varieties were used to investigate the analyzing method for 7S and 11S globulins. 7S and 11S globulins couble be fractionated by their different solubilities in tris buffers. Adjusting the pH and tris concentration were major factors affecting the precipitation of the two globulins. And it was possible to screen the soybean genotypes having aberrant subunit compositions of the two globulins by an sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) of total soybean proteins. The ratio of 11S to 7S globulin ranged from 1.29 to 1.38. This paper also dealed with the contribution of protein components in soybean seeds to the physical properties of soycurd. It indicated that the soycurd from crude 11S was remarkably harder than that from crude 7S, and springiness and cohesiveness were slightly higher in soycurd having higher proportion of 11S. So, it may concluded that proportion of protein components in soybean seed can be important factor which controls the suitability for soycurd or other foods.

• Food Science and Biotechnology
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• v.17 no.1
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• pp.52-57
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• 2008

The effects of transglutaminase (TG) on the pasting and rheological properties of different wheat cultivars ('Sharpshooter', 'Russ', and 'AcAriss') blended with barley (40%) or soy (20%) flour were investigated. In the rapid visco-analyzer (RVA) pasting profile, the addition of barley or soy flour to wheat flour samples induced a decrease in peak, trough, final viscosity, breakdown and setback values. However, TG treatment of these blends significantly increased peak viscosity and breakdown (p<0.05). In particular, TG treatment greatly increased the breakdown of wheat flour blended with soy flour, indicating that the cross-linking of proteins through TG may somehow be related to an increase in starch granule rupturing in pastes. Storage (G') and loss (G") moduli of the sample pastes increased with an increase in frequency ($\omega$), while complex viscosity (${\eta}*$) decreased. In all wheat cultivars, G', G", and $\eta$ were decreased by the addition of barley or soy flour, or TG treatment. Results suggest that protein cross-linking by TG can produce unique and improved properties in wheat flours blended with barley or soy flour.

• Development and Reproduction
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• v.12 no.2
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• pp.141-149
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• 2008

This study was conducted to develop an efficient cryopreservation method of human embryonic stem (ES) cells using vitrification. In an initial experiment, sub-clumps of human ES cells (CHA-hES3 and CHA-hES4) were vitrified using grids after incubation with STO feeder cells for 1 or 16 h (Groups 1-1 and 1-2, respectively). After storage for $2{\sim}4$ months, thawed clumps were re-plated on a fresh feeder layer. The survival rates of warmed CHA-hES3 and CHA-hES4 cells of Group 1-2 were significantly higher than those of the corresponding Group 1-1 cells. In the second experiment, human ES cells were vitrified after incubation with feeder or feeder-conditioned medium (Groups 2-1 to -7). Relative mRNA expression of BM proteins and survival rates were increased following incubation of ES cells with fresh feeder cells for 16 h. In conclusion, increasing of tight adhesion between ES cells by extended incubation with feeder could reduce cryoinjury after vitrifying/warming.

• Journal of Life Science
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• v.17 no.9 s.89
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• pp.1294-1297
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• 2007

To define diversity of domestic radish, we analysis genetic relationship of anti-fungal protein genes from several domestic radish (Raphanus sativus L.) seeds. We have isolated from domestic radish (Baekwoon) anti-fungal protein named RAP[12]. In this report, we isolate RNAs and raw protein from radish seeds then, RT-PCR analysis was done with another known anti-fungal sequences of radish from Gene Bank/EMBL and anti-fun- gal, anti-yeast activity were done against Bot교tis cenerea, Saccharomyces cerevisiaeι Candida albicans with it's raw proteins. The anti-fungal activity was shown used all seeds but anti-yeast activity was shown only two seeds (Myungsan, Baekwoon). RT-PCR products (about 0.2 Kb) were not shown only two seeds. To identify the sequencing relationship of the domestic radish, we have cloned and sequenced RAP genes of the radish and analysis the sequence relationship with clustalw program. Thus we report the result that there are some different relationship between domestic radish and known other radish's anti- fungal protein[15].