Eun Kyung Cho

A nuclear-localized HSP70 confers thermoprotective activity and drought-stress tolerance on plants

To investigate the function of nuclear-localized plant HSP70, we used NtHSP70-1 isolated from Nicotiana tabacum. The subcellular localization of NtHSP70-1 was identified by fluorescence microscopy for NtHSP70-1/GFP or smGFP fusion proteins in onion epidermal cells, obtained using particle gun bombardment. To analyze the drought-stress tolerance and thermoprotective role of NtHSP70-1, we obtained transgenic tobacco plants that constitutively expressed elevated levels of NtHSP70-1 as well as transgenic plants containing either the vector alone or else having NtHSP70-1 in the antisense orientation. From analysis for genomic DNA in transgenic seedlings after heat stress, NtHSP70-1 helps to prevent the fragmentation and degradation of nuclear DNA during heat stress. In addition, seedlings constitutively overexpressing NtHSP70-1 grew to be healthy plants, whereas transgenic vector or antisense seedlings resulted in death after heat-/drought-stress.

Effect of Brown Rice Flour on Muffin Quality

The purpose of this study was to examine the qualities of muffins with 20, 40, and 60% brown rice flour (BRF). The muffins containing 20, 40, and 60% BRF were lower than control muffins (made with regular flour) in weight, height, pH, and moisture content. No significant differences were observed between BRF muffins in weight and moisture content; however, height and pH decreased with increasing amounts of BRF added (p and was not significantly different than BRF muffins (p>0.05). The hardness and resilience in the controls were higher than BRF muffins, but increasing the amount of BRF added in muffins increased both hardness and resilience (p0.05). In sensory evaluation, the external color in muffins with 20% BRF and the internal color in controls were the highest (p

Nitrite Scavenging and Alcohol Metabolizing Activities of Hot Water Extract from Makgeoly and Its Angiotensin Converting Enzyme Inhibitory Effect

In this study, we investigated the antioxidant activities, alcohol metabolizing activities, nitrite scavenging ability, angiotensin converting enzyme (ACE), and elastase inhibitory effects of hot water extract from Makgeoly (HWM). Antioxidant activities were measured by using 2,2 diphenyl 1 picryl hydrazyl (DPPH) free radical scavenging activity and SOD (superoxide dismutase) like activity. The DPPH radical scavenging activity and SOD like activity of HWM were remarkably increased in a dose dependent manner and were 48.0% and 98.7% at 10 ㎎/㎖, respectively. To determine the influence of HWM on alcohol metabolizing activity, the generating activities of reduced nicotinamide adenine dinucleotide (NADH) by alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) were measured. The facilitating rates of ADH and ALDH activity by HWM were remarkably increased in a dose dependent manner and were 70.2% and 64.1% at 10 ㎎/㎖, respectively. The inhibitory activity against angiotensin converting enzyme (ACE) of HWM was increased in a dose dependent manner and was 74.2% at 10 ㎎/㎖. The nitrite scavenging ability of HWM showed the most remarkable effect at pH 1.2 and 2 ㎎/㎖. These results indicated that HWM may have valuable biological properties owing to their antioxidant activities, ADH and ALDH activity, nitrite scavenging ability, and ACE inhibitory activity.

α-Glucosidase Inhibitory Effects for Solvent Fractions from Methanol Extracts of Sargassum fulvellum and Its Antioxidant and Alcohol-Metabolizing Activities

We investigated the physiological activity and solvent-partitioned fractions of methanol extracts from the green seaweed Sargassum fulvellum. The methanol extract from S. fulvellum was sequentially fractionated with n-hexane (SFMH), methanol (SFMM), buthanol (SFMB), and water (SFMA). We investigated the antioxidant activities of solvent fractions from S. fulvellum by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity and an SOD activity assay. DPPH radical scavenging capacity of SFMM was 79.5% at 10 mg/ml. SOD activity of SFMM was 79.9% at 10 mg/ml. Nitrite scavenging activities of solvent fractions from S. fulvellum were investigated under different pH conditions and showed the most remarkable effect at pH 1.2. In particular, the activity of SFMB was higher than the other fractions. ADH activity and ALDH activity of SFMM were 177.0% and 167.4% at 10 mg/ml, respectively. α-Glucosidase inhibitory activity of SFMH increased in a dose-dependent manner and was about 94.1% at 2 mg/ml. Elastase inhibitory activity was 93.2% at 2 mg/ml. These results revealed that S. fulvellum extracts have strong antioxidant and alcohol dehydrogenase activities and α-glucosidase inhibitory activity, suggesting that S. fulvellum extracts have potential as a source of natural products for health and beauty.

Functional Mechanism of Calmodulin for Cellular Responses in Plants

Calcium (Ca2?) plays pivotal roles as an intracellular second messenger in response to a variety of stimuli, including light, abiotic- and biotic stresses and hormones. Ca2? sensor is Ca2?-binding protein known to function in transducing signals by activating specific targets and pathways. Among Ca2?-binding proteins, calmodulin (CaM) has been well reported to regulate the activity of downstream target proteins in plants and animals. Especially plants possess multiple CaM genes and many CaM target proteins, including unique protein kinases and transcription factors. Thus, plants are possible to perceive different signals from their surroundings and adapt to the changing environment. However, the function of most of CaM or CaM-related proteins have been remained uncharacterized and unknown. Hence, a better understanding of the function of these proteins will help in deciphering their roles in plant growth, development and response to environmental stimuli. This review focuses on Ca2?-CaM messenger system, CaM-associated proteins and their role in responses to external stimuli of both abiotic and biotic stresses in plants.

Development of Functional Beverage (SanYa) from Fermented Medical Plants and Evaluation of Its Physiological Activities

This study was investigated to analyze the contents of flavonoid compounds and the effects of fermentation on the physiological activities of medical plants, also known as SanYa (SY). Antioxidative activity of the fermented SanYa (FSY) was measured by using DPPH radical scavenging and SOD-like activity. DPPH radical scavenging and SOD-like activity of FSY were 94.3% and 45.0%, respectively. Nitric oxide (NO) synthesis was increased 11 times through the addition of FSY. However, NO production of the macrophages RAW264.7 cells stimulated with lipopolysaccharide (LPS) was reduced to 56% through the addition of FSY. FSY showed fibrinolytic activity and indicated about 69.8% and 73.7% of xanthine oxidase and angiotensin converting enzyme inhibitory activities, respectively. These results suggested that FSY plays a significant role in fibrinolytic activity and have strong xanthine oxidase and angiotensin converting enzyme inhibitory activities.

Overexpression and characterization of thermostable chitinase from Bacillus atrophaeus SC081 in Escherichia coli

The chitinase-producing strain SC081 was isolated from Korean traditional soy sauce and identified as Bacillus atrophaeus based on a phylogenetic analysis of the 16S rDNA sequence and a phenotypic analysis. A gene encoding chitinase from B. atrophaeus SC081 was cloned in Escherichia coli and was named SCChi-1 (GQ360078). The SCChi-1 nucleotide sequences were composed of 1788 base pairs and 596 amino acids, which were 92.6, 89.6, 89.3, and 78.9% identical to those of Bacillus subtilis (ABG57262), Bacillus pumilus (ABI15082), Bacillus amyloliquefaciens (ABO15008), and Bacillus licheniformis (ACF40833), respectively. A recombinant SCChi-1 containing a hexahistidine tag at the amino- terminus was constructed, overexpressed, and purified in E. coli to characterize SCChi-1. H(6)SCChi-1 revealed a hydrolytic band on zymograms containing 0.1% glycol chitin and showed the highest lytic activity on colloidal chitin and acidic chitosan. The optimal temperature and pH for chitinolytic activity were 50°C and pH 8.0, respectively.

Anti-Inflammatory and Antidiabetic Effects of Brown Rice (Oryza sativa L.) Extracts

현미의 기능성을 증명하기 위하여 열수, 에탄올 추출하여 여러 가지 생리활성에 대하여 조사하였다. 우선, 아 질산염 소거능 분석에서는 현미 열수와 에탄올 추출물 1 mg/ml 농도, pH 1.2에서 75.4와 94.9%을 나타내었고, xanthine oxidase 저해능은 현미 에탄올 추출물 10 mg/ml에서 72.9%로 같은 농도의 열수 추출물보다 높게 측정되었다. 현미의 소화율(

Antioxidant, Antidiabetic, and Anti-Inflammatory Effects of Extracts and Fractions from Parthenocissus tricuspidata Stems

44.46{\pm}6.09

Biological Analysis of Enzymatic Extracts from Capsosiphon Fulvescens Using the Microbulbifer sp. AJ-3 Marine Bacterium

%)은 백미의 소화율(