• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.36-36
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• 2017

Out of twenty common protein amino acids, there are many kinds of non protein amino acids (NPAAs) that exist as secondary metabolites and exert ecological functions in plants. Mimosine (Mim), one of those NPAAs derived from L. leucocephala acts as an iron chelator and reversely block mammalian cell cycle at G1/S phases. Cysteine (Cys) is decisive for protein and glutathione that acts as an indispensable sulfur grantor for methionine and many other sulfur-containing secondary products. Cys biosynthesis includes consecutive two steps using two enzymes-serine acetyl transferase (SAT) and O-acetylserine (thiol)lyase (OASTL) and appeared in plant cytosol, chloroplast, and mitochondria. In the first step, the acetylation of the ${\beta}$-hydroxyl of L-serine by acetyl-CoA in the existence of SAT and finally, OASTL triggers ${\alpha}$, ${\beta}$-elimination of acetate from OAS and bind $H_2S$ to catalyze the synthesis of Cys. Mimosine synthase, one of the isozymes of the OASTLs, is able to synthesize Mim with 3-hydroxy-4-pyridone (3H4P) instead of $H_2S$ for Cys in the last step. Thus, the aim of this study was to clone and characterize the cytosolic (Cy) OASTL gene from L. leucocephala, express the recombinant OASTL in Escherichia coli, purify it, do enzyme kinetic analysis, perform docking dynamics simulation analysis between the receptor and the ligands and compare its performance between Cys and Mim synthesis. Cy-OASTL was obtained through both directional degenerate primers corresponding to conserved amino acid region among plant Cys synthase family and the purified protein was 34.3KDa. After cleaving the GST-tag, Cy-OASTL was observed to form mimosine with 3H4P and OAS. The optimum Cys and Mim reaction pH and temperature were 7.5 and $40^{\circ}C$, and 8.0 and $35^{\circ}C$ respectively. Michaelis constant (Km) values of OAS from Cys were higher than the OAS from Mim. Inter fragment interaction energy (IFIE) of substrate OAS-Cy-OASTL complex model showed that Lys, Thr81, Thr77 and Gln150 demonstrated higher attraction force for Cys but 3H4P-mimosine synthase-OAS intermediate complex showed that Gly230, Tyr227, Ala231, Gly228 and Gly232 might provide higher attraction energy for the Mim. It may be concluded that Cy-OASTL demonstrates a dual role in biosynthesis both Cys and Mim and extending the knowledge on the biochemical regulatory mechanism of mimosine and cysteine.

• Journal of Korean Society of Forest Science
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• v.104 no.1
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• pp.67-75
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• 2015

This research is to investigate the four years growth mountain-cultivated ginseng ripened twenty-two weeks into four years fermented persimmon vinegar (tentatively: Sansamcho) ingestion on obese-related factors during dietary control. The Sansamcho was ingested orally, two times a day, after every meal for six weeks to the male rats. Groups were divided into the control (CON), the restricted diet (RD), and the weight cycling (WC). And, each groups has its own sub-groups as the -control (-CON), 2.5 times diluted Sansamcho ingestion (-MPV2.5), and 5.0 times diluted Sansamcho ingestion (-MPV5.0) groups, respectively. The number of rat was consisted of seven in each group. After six weeks rearing periods was done, abdominal fats (retroperitoneal fat, mesentery fat, and epididymal fat) and energy metabolic-related protein (AMPK: AMP-activated protein kinase; PPAR-${\alpha}$: peroxisome proliferator-activated receptor-${\alpha}$; and CPT-1: carnitine palmitoyltransferase-1) were weighed and analyzed. Amount of stored fat was significantly or tended to decrease by Sansamcho ingestion. In addition, sum of fats increasing were suppressed by the material. On the contrary, energy metabolism-related protein expression was significantly increased or tended to increase by Sansamcho ingestion. This results suggested that increased energy metabolism using Sansamcho was restrained effectively visceral fat store by high-fat diet and/or dietary control. In other words, it has a good function to suppress weight cycling which is the most insoluble problem. Therefore, the fusion material, Sansamcho, may expect to utilize as the obese-suppression-food.

• Korean Journal of Ichthyology
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• v.31 no.3
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• pp.123-130
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• 2019

The olfactory organ of the Korean endemic fish, Rhodeus uyekii, a mussel-spawning species, was researched anatomically, histologically and histochemically, for looking into a relation to the physical and chemical condition of its habitat and ecological habit, using stereo microscopy, light microscopy and scanning electron microscopy. The external structure of the olfactory organ consists of the semicircular-shaped anterior nostril with arched shape at its forward position, posterior nostrils and the nasal flap. Within the olfactory chamber, it has the rosette structure with 14 to 15 lamellae which is largely divided into the sensory and non-sensory regions. The sensory region has the olfactory receptor neurons, the supporting cells, the basal cells, the lymphatic cells, and the plasma cells, while the non-sensory region has the stratified epithelial cells, the mucous cells with sulfomucin and 1 type of unidentified cell. In particular, the arched feature in the anterior nostril and the mucous cell of sulfomucin were unique.