• The Korean Journal of Physiology and Pharmacology
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• 제16권3호
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• pp.219-224
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• 2012

Understanding how the b-wave of the electroretinogram (ERG) is generated by full-field light stimulation is still a challenge in visual neuroscience. To understand more about the origin of the b-wave, we studied the contributions of gap junctions to the ERG b-wave. Many types of retinal neurons are connected to similar and different neighboring neurons through gap junctions. The photopic (cone-dominated) ERG, stimulated by a small light beam, was recorded from goldfish (Carassius auratus) using a corneal electrode. Data were obtained before and after intravitreal injection of agents into the eye under a photopic illumination level. Several agents were used to affect gap junctions, such as dopamine D1 and D2 receptor agonists and antagonists, a nitric oxide (NO) donor, a nitric oxide synthase (NOS) inhibitor, the gap junction blocker meclofenamic acid (MFA), and mixtures of these agents. The ERG b-waves, which were enhanced by MFA, sodium nitroprusside (SNP), SKF 38393, and sulpiride, remained following application of a further injection of a mixture with MFA. The ERG b-waves decreased following $N^G$-nitro-L-arginine methyl ester (L-NAME), SCH 23390, and quinpirole administration but were enhanced by further injection of a mixture with MFA. These results indicate that gap junction activity influences b-waves of the ERG related to NO and dopamine actions.

• 한국식품과학회지
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• 제20권3호
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• pp.293-302
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• 1988

본 연구는 모과의 비휘발성 성분에 과한 조성을 규명하기 위한 기초 연구 과제로써 행하여졌다. 주요 비휘발성 성분은 유리 아미노산의 경우 valine, asparagin ${\gamma}-aminobutyric\;acid$, aspartic acid 와 serine 이 전체의 72%를 차지하고 arginine, tyrosine, methionine과 tryptophan은 거의 검출되지 않아다. Peptide 구성 아미노산으로는 주로 glutamic acid와 glutamine이었으며 cysteic acid, methione sulfone과 tryptophan은 검출되지 않았다. 핵산관련 물질의 분석 결과 cytosine, UMP, CMP는 소량 존재하셨으며 GMP, IMP, AMP는 검출되지 않았다. 당 분석결과 주성분은 glucose, sorbose, sucrose, fructose였으며 fructose 함량이 가장 높은 것으로 판명되었다. GC 및 GC-MS방법에 의해 총 11성분의 유기산이 동정 되었으며 이들중 tartaric acid및 ${\alpha}-ketoglutaric\;acid$가 주성분이었다. 정량된 총 비타민 C 함량은 386.6 mg%였으며 ascorbic-acid dehydroascorbic acid와 2,3-diketo-L-gulonic acid는 각각 28.8mg%, 154.5mg%, 197.3mg%였다. 무기성분으로는 칼슘과 인이 주요 성분으로 나타났으며 카드뮴, 구리, 납은 소량 존재하였다. 모과의 천연 및 합성 extract에 대한 관능검사의 결과 유리형, 아미노산, 당, 유기산, 비타민 C및 무기질의 맛의 주성분으로 판명되었다. 따라서 모과의 향미 성분 중 비휘발성 성분은 주로 상기 다섯 그룹에 의해서 나타남을 확인하였다.

• 한국작물학회지
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• 제47권3호
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• pp.189-195
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• 2002

야생종의 콩나물 관련형질의 특성 및 주요성분을 재배종과 비교하여 야생종을 소립 나물콩 육성을 위한 교배친으로서의 이용 가능성을 검토하기 위해 실시한 결과를 요약하면 다음과 같다. 1. 야생종과 재배종의 콩나물 특성을 비교한 결과 하배축의 길이와 수량에는 차이가 없었으나, 콩나물의 전체길이, 하배축 두께, 개체당 무게, 상품률에서는 재배종이 우수하였고, 잔뿌리의 수와 뿌리의 길이에서는 야생종이 작고 짧아 야정종이 우수한 것으로 평가되었다. 2. 조지방 및 sucrose함량은 재배종이, 조단백질 함량은 야생종이 높았으며, 지방산중 oleic acid는 재배종이 linoleic acid는 야생종이 높았고, isoflavone함량에서는 두 종간 차이가 없었다. 17개의 아미노산 중 유의적인 차이가 인정된 aspartic acid, lysine, arginine등 10개 아미노산은 모두 야생종에서 높았다. 3. 콩나물 하배축의 색차는 야생종에서 백색도가 높고 적색도가 낮아 재배종보다는 야생종이 우수한 것으로 평가되었다.

• Molecules and Cells
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• 제21권3호
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• pp.337-342
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• 2006

Interstitial cells of Cajal (ICCs) are pacemaker cells that activate the periodic spontaneous depolarization (pacemaker potentials) responsible for the production of slow waves in gastrointestinal smooth muscle. The effects of vasoactive intestinal polypeptide (VIP) on the pacemaker potentials in cultured ICCs from murine small intestine were investigated by whole-cell patch-clamp techniques. Addition of VIP (50 nM-$1{\mu}M$) decreased the amplitude of pacemaker potentials and depolarized resting membrane potentials. To examine the type of receptors involved in ICC, we examined the effects of the $VIP_1$ agonist and found that it had no effect on pacemaker potentials. Pretreatment with $VIP_1$ antagonist ($1{\mu}M$) for 10 min also did not block the VIP (50 nM)-induced effects. On the other hand exposure to 1H-(1,2,4)oxadiazolo(4,3-A)quinoxalin-1-one (ODQ, $100{\mu}M$), an inhibitor of guanylate cyclase, prevented VIP inhibition of pacemaker potentials. Similarly KT-5823 ($1{\mu}M$) or RP-8-CPT-cGMPS ($10{\mu}M$), inhibitors of protein kinase G (PKG) blocked the effect of VIP (50 nM) on pacemaker potentials as did N-nitro-L-arginine (L-NA, $100{\mu}M$), a non-selective nitric oxide synthase (NOS) inhibitor. These results imply that the inhibition of pacemaker activity by VIP depends on the NO-cGMP-PKG pathway.

• Biomolecules & Therapeutics
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• 제23권1호
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• pp.19-25
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• 2015

Vascular endothelial growth factor (VEGF) is an important regulator of neovascularization. Hypoxia inducible nitric oxide (NO) enhanced the expression of VEGF and thymosin beta-4 ($T{\beta}4$), actin sequestering protein. Here, we investigated whether NO-mediated VEGF expression could be regulated by $T{\beta}4$ expression in HeLa cervical cancer cells. Hypoxia inducible NO production and VEGF expression were reduced by small interference (si) RNA of $T{\beta}4$. Hypoxia response element (HRE)-luciferase activity and VEGF expression were increased by the treatment with N-(${\beta}$-D-Glucopyranosyl)-N2-acetyl-S-nitroso-D, L-penicillaminamide (SNAP-1), to generate NO, which was inhibited by the inhibition of $T{\beta}4$ expression with $T{\beta}4$-siRNA. In hypoxic condition, HRE-luciferase activity and VEGF expression were inhibited by the treatment with $N^G$-monomethyl-L-arginine (L-NMMA), an inhibitor to nitric oxide synthase (NOS), which is accompanied with a decrease in $T{\beta}4$ expression. VEGF expression inhibited by L-NMMA treatment was restored by the transfection with pCMV-$T{\beta}4$ plasmids for $T{\beta}4$ overexpression. Taken together, these results suggest that $T{\beta}4$ could be a regulator for the expression of VEGF via the maintenance of NOS activity.

• Korean Chemical Engineering Research
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• 제58권1호
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• pp.21-28
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• 2020

The stem extract from Pyrus serotina var has natural antioxidant ability, but the extraction method does not result in a soluble compound in cosmetic formulations. This study investigated the cosmetic efficacy of the Pyrus serotina var stem extract and its epidermis permeation ability when combined with polymer micelles and a cell penetrating peptide. The total concentration of polyphenol compounds was determined to be 103.1644 ± 1.38 mg/g in the ethanol extract and 78.97 ± 1.45 mg/g in the hydrothermal extract. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging effects were 55.94 ± 0.22% in the ethanol extract at 1,000 mg/L. Superoxide dismutase (SOD) activity rates were 104.05 ± 3.28% in the ethanol extract at 62.5 mg/L. The elastase inhibition rate was 67.21 ± 2.72% in the ethanol extract at 1,000 mg/L. An antimicrobial effect was observed in the Propionibacterium acnes strain. In the epidermal permeability experiment, it was confirmed that formulation of the polymer micelle containing the Pyrus serotina var stem extract and cell penetrating peptide (R6, hexa-D-arginine) showed small particle size and much better skin permeability. The cumulative amount of total Pyrus serotina var stem extract that penetrated to the skin over time increased over 24 hours in three formulations. The three formulations showed 51.61 ㎍/㎠ (Formulation 0), 75.97 ㎍/㎠ (Formulation 1) and 95.23 ㎍/㎠ (Formulation 2) skin penetration, respectively. Therefore, it was confirmed that the ethanol extracts of Pyrus serotina var stem showed good cosmetic efficacy and excellent epidermis permeation ability when combined with a polymer micelle and cell penetrating peptide. Thus, this extract has the potential to be used as a safe and natural cosmetic material in the future.

• 한국식품과학회지
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• 제47권6호
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• pp.751-756
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• 2015

소금의 과량 섭취가 건강에 유해한 영향을 미칠 수 있어 이를 해결하기 위한 다양한 연구가 진행되고 있다. 최근 우리나라의 전통 발효 식품인 간장, 액젓 등이 짠맛을 증진한다는 보고가 있어 이에 대한 연구가 활발히 이루어지고 있다. 본 연구에서는 어간장과 액젓의 주요 재료로 사용되는 멸치를 효소 가수분해한 eHAP의 짠맛 증진 효과에 대해 살펴보았다. 동일한 소금농도의 용액에 eHAP의 첨가량을 달리하였을 때 첨가량이 증가할수록 짠맛 증진효과도 증가하여, 50 mmol/L의 용액에 2%의 eHAP를 첨가하였을 경우 $67.79{\pm}6.35%$의 짠맛 강도를 인지하였으며, 용액의 소금농도가 높을수록 eHAP의 첨가에 따른 짠맛 증진효과가 더 크게 나타났다. 이러한 짠맛 증진 효과는 멸치 단백질 가수분해물에 다량 함유하고 있는 $\small{L}$-lysine과 $\small{L}$-arginine과 감칠맛을 나타내는 glutamic acid와 aspartic acid에 상호작용에 의한 것으로 보인다. 0.1%에서 2%까지 eHAP의 첨가량을 달리하였을 경우 최소 0.37%에서 최대 35.58%의 짠맛 증진 효과를 나타내어 멸치단백질 효소가수분해물이 염미 증진제로서 향후 활용 가능성이 있는 것으로 판단된다.

• 한국수산과학회지
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• 제48권2호
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• pp.178-186
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• 2015

Protease inhibitors (PI) of trypsin and papain as target proteases from the roe of bastard halibut Paralichthys olivaceus were fractionated out using ammonium sulfate precipitation (A), DEAE 650M anion exchange chromatography (D), and Sephacryl S-300 gel filtration (S). The recovery percentages of the fractions with the strongest inhibitory activity for each fractionation method were 13% for the A4 fraction, 21.2% for the D3 fraction, and 21.3% for the S2 fraction, with specific inhibitory activities of the fractions toward trypsin and casein of 168, 139, and 218 U/mg, respectively, while no inhibition of papain was observed. The $IC_{50}$ for the trypsin-specific substrate $N{\alpha}$-benzoyl-$\small{L}$-arginine-p-nitroanilide (BAPNA) was 0.65, 1.55, 2.26, and 2.85 mg/mL for the A4, S2, A3, and D3 fractions, respectively. These results suggest that chromatographic fractionation methods (D and S) based on the molecular mass and charge of the protein were more effective at fractionating PI than was ammonium sulfate precipitation based on protein solubility, and that the bastard halibut roe extract acts as a serine protease inhibitor. Therefore, the PI fraction from fish roe might be useful for inhibiting proteases in foodstuffs, and could constitute an alternative food-grade inhibitor for the surimi industry.

• Journal of Microbiology and Biotechnology
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• 제27권5호
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• pp.1023-1031
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• 2017

The conformational change of cellular prion protein ($PrP^C$) to its misfolded counterpart, termed $PrP^{Sc}$, is mediated by a hypothesized cellular cofactor. This cofactor is believed to interact directly with certain amino acid residues of $PrP^C$. When these are mutated into cationic amino acid residues, $PrP^{Sc}$ formation and prion replication halt in a dominant negative (DN) manner, presumably due to strong binding of the cofactor to mutated $PrP^C$, designated as DN PrP mutants. Previous studies demonstrated that plasminogen and its kringle domains bind to PrP and accelerate $PrP^{Sc}$ generation. In this study, in vitro binding analysis of kringle domains of plasminogen to Q167R DN mutant PrP (PrPQ167R) was performed in parallel with the wild type (WT) and Q218K DN mutant PrP (PrPQ218K). The binding affinity of PrPQ167R was higher than that of WT PrP, but lower than that of PrPQ218K. Scatchard analysis further indicated that, like PrPQ218K and WT PrP, PrPQ167R interaction with plasminogen occurred at multiple sites, suggesting cooperativity in this interaction. Competitive binding analysis using $\small{L}$-lysine or $\small{L}$-arginine confirmed the increase of the specificity and binding affinity of the interaction as PrP acquired DN mutations. Circular dichroism spectroscopy demonstrated that the recombinant PrPs used in this study retained the ${\alpha}$-helix-rich structure. The ${\alpha}$-helix unfolding study revealed similar conformational stability for WT and DN-mutated PrPs. This study provides an additional piece of biochemical evidence concerning the interaction of plasminogen with DN mutant PrPs.

• The Korean Journal of Physiology and Pharmacology
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• 제19권6호
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• pp.533-542
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• 2015

Little human tissue data are available for slow waves and migrating motor complexes, which are the main components of small bowel motility. We investigated the electrophysiological and mechanical characteristics of human ileal motility, in vitro. Ileum was obtained from patients undergoing bowel resection. Electrophysiological microelectrode recordings for membrane potential changes and mechanical tension recordings for contraction from smooth muscle strips and ileal segments were performed. Drugs affecting the enteric nervous system were applied to measure the changes in activity. Slow waves were detected with a frequency of 9~10/min. There were no cross-sectional differences in resting membrane potential (RMP), amplitude or frequency between outer and inner circular muscle (CM), suggesting that electrical activities could be effectively transmitted from outer to inner CM. The presence of the interstitial cell of Cajal (ICC) at the linia septa was verified by immunohistochemistry. Contractions of strips and segments occurred at a frequency of 3~4/min and 1~2/min, respectively. The frequency, amplitude and area under the curve were similar between CM and LM. In segments, contractions of CM were associated with LM, but propagation varied with antegrade and retrograde directions. Atropine, $N^W$-oxide-L-arginine, and sodium nitroprusside exhibited different effects on RMP and contractions. There were no cross-sectional differences with regard to the characteristics of slow waves in CM. The frequency of contractions in smooth muscle strips and ileal segments was lower than slow waves. The directions of propagation were diverse, indicating both mixing and transport functions of the ileum.