• Molecules and Cells
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• 제46권6호
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• pp.337-344
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• 2023

N-glycosylation, a common post-translational modification, is widely acknowledged to have a significant effect on protein stability and folding. N-glycosylation is a complex process that occurs in the endoplasmic reticulum (ER) and requires the participation of multiple enzymes. GlcNAc-1-P-transferase (GPT) is essential for initiating N-glycosylation in the ER. Tunicamycin is a natural product that inhibits N-glycosylation and produces ER stress, and thus it is utilized in research. The molecular mechanism by which GPT triggers N-glycosylation is discussed in this review based on the GPT structure. Based on the structure of the GPT-tunicamycin complex, we also discuss how tunicamycin reduces GPT activity, which prevents N-glycosylation. This review will be highly useful for understanding the role of GPT in the N-glycosylation of proteins, as well as presents a potential for considering tunicamycin as an antibiotic treatment.

• Molecules and Cells
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• 제25권4호
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• pp.494-503
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• 2008

Many therapeutic glycoproteins have been successfully generated in plants. Plants have advantages regarding practical and economic concerns, and safety of protein production over other existing systems. However, plants are not ideal expression systems for the production of biopharmaceutical proteins, due to the fact that they are incapable of the authentic human N-glycosylation process. The majority of therapeutic proteins are glycoproteins which harbor N-glycans, which are often essential for their stability, folding, and biological activity. Thus, several glyco-engineering strategies have emerged for the tailor-making of N-glycosylation in plants, including glycoprotein subcellular targeting, the inhibition of plant specific glycosyltranferases, or the addition of human specific glycosyltransferases. This article focuses on plant N-glycosylation structure, glycosylation variation in plant cell, plant expression system of glycoproteins, and impact of glycosylation on immunological function. Furthermore, plant glyco-engineering techniques currently being developed to overcome the limitations of plant expression systems in the production of therapeutic glycoproteins will be discussed in this review.

• 대한화장품학회지
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• 제30권1호
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• pp.29-32
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• 2004

내형질 세망 조직에서 N-글리코실레이션 과정의 초기 단계를 차단하면 멜라닌 생 합성의 주 효소인 티로시나제의 활성이 저해된다. 본 연구에서는 in vitro 환경에서 N-글리코실레이션 저해제의 활성을 증가시키고자 전달체로 pH 감응성을 갖는 나노크기의 지질구조체를 제조하고 이를 평가하였다. 이 pH 감응성 지질구조체 Melexsome은 일반적인 지질성분인 포스포리피드와 콜레스테롤 기반의 지질안정 성분으로 구성되며, 통상적인 리포좀 제조법에 따라 제조되었다. 글리코실레이션 저해 성분물질을 포집시킨 Melel[some의 효과는 EndoH ＆ PNGaseF 분해와 western blotting 방법에 의해 평가하였고, 멜라닌 합성량 또한 측정 되었다. 이 결과, pH 감응성을 갖도록 제조된 Melexsome이 N-글리코실레이션 저해제의 효능을 효과적으로 증진시킴을 알 수 있었다. 또한, 공초점 주사 현미경에 의한 세포관찰 결과에 따르면 Melexsome은 여타의 전달체에 비하여 세포질 내에 보다 효과적으로 전달되는 것으로 보여지며, 따라서 이같은 양친성 지실성분 기반의 pH 감응성 나노 전달체는 N-글리코실레이션 저해제의 전달 시스템으로서 미백 화장료 제품이 가져야 하는 침착된 색소에 의해 어두워진 피부톤의 개선 효과를 극대화 시키는데 적합하다고 여겨진다.

• Journal of Microbiology
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• 제45권5호
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• pp.431-440
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• 2007

A silkworm (Bombyx mori L.) extract known to contain naturally occurring iminosugars, including 1-deoxynojirimycin (1-DNJ) derived from the mulberry tree (Morus alba L.), was evaluated in surrogate HCV and HBV in vitro assays. Antiviral activity of the silkworm extract and one of its purified constituents, 1-DNJ, was demonstrated against bovine viral diarrhea virus (BVDV) and GB virus-B (GBV-B), both members of the Flaviviridae family, and against woodchuck hepatitis virus (WHV) and hepatitis B virus (HBV), both members of the Hepadnaviridae family of viruses. The silkworm extract exhibited a 1,300 fold greater antiviral effect against BVDV in comparison to purified 1-DNJ. Glycoprotein processing of BVDV envelope proteins was disrupted upon treatment with the naturally derived components. The glycosylation of the WHV envelope proteins was affected largely by treatment with the silkworm extract than with purified 1-DNJ as well. The mechanism of action for this therapy may lie in the generation of defective particles that are unable to initiate the next cycle of infection as demonstrated by inhibition of GBV-B in vitro. We postulate that the five constituent iminosugars present in the silkworm extract contribute, in a synergistic manner, toward the antiviral effects observed for the inhibition of intact maturation of hepatitis viral particles and may complement conventional therapies. These results indicate that pre-clinical testing of the natural silkworm extract with regards to the efficacy of treatment against viral hepatitis infections can be evaluated in the respective animal models, in preparation for clinical trials in humans.

• 대한화장품학회지
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• 제35권1호
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• pp.73-78
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• 2009

닭의장풀(Commelina communis L. Dayflower) 추출물의 미백효능을 확인하기 위하여 B16 melanoma 세포를 이용하여 melanin 생성에 관련된 다양한 실험을 실시하였다. 닭의장풀 추출물은 버섯 tyrosinase 활성 실험에서 저해 효과를 보이지 않았으나, melanin 생성 저해효과를 나타내었다. B16-F10 멜라노마 세포를 이용한 활성시험 결과에서, 닭의장풀 추출물은 1,000 ${\mu}g/mL$의 농도에서 약 32%의 멜라닌 생성을 억제하였으며, 세포내 티로시나제 활성 억제 능도 우수하여 닭의장풀 추출물 250 ${\mu}/mL$ 이상의 농도에서 50% 이상의 저해 효과를 보였다. 추출물의 생성 기작에 대한 영향을 조사한 결과, melanin 합성의 key protein 인 tyrosinase 발현의 우수한 저해 능력을 보였고, tyrosinase related protein-1 (TRP-1)의 발현 억제와 tyrosinase related protein-2 (TRP-2)의 N-glycosylatin 억제를 통해 melanin 합성이 억제되는 것으로 분석되었다. 따라서 닭의장풀 추출물은 melanin 합성에 필수적인 효소(tyrosinase, TRP-1)의 발현 저해 및 TRP-2의 N-glycosylation 억제를 통해 미백 효과를 나타내는 것으로 확인되었으며, 이에 따라 본 추출물은 melanin 합성의 효소 경로를 저해하는 미백 소재로 활용할 수 있을 것으로 사료된다.

• Journal of Microbiology
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• 제45권6호
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• pp.578-582
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• 2007

The primary objective of this study was to assess the in vitro melanogenesis inhibitory effects of methanolic extracts of the edible and medicinal lichens, Umbilicaria (Gyrophora) esculenta and Usnea longissima. The quantities of the total phenolic compounds of methanolic extract of the two lichen extracts were determined to be 1.46% and 2.62%, respectively. In order to evaluate the antioxidative effects of the extracts, we also measured electron donating abilities (EDA) and lipid peroxidation rates. The EDA values measured by the reduction of 1.1'-diphenyl-2-picrylhydrazyl (DPPH) were 72.8% and 80.7% for the extracts, with $SC_{50}$ (median scavenging concentration) values of $1.29{\pm}0.05\;mg/ml$ and $1.03{\pm}0.06\;mg/ml$, respectively. The rates of inhibition of lipid peroxidation using linoleic acid were 92.1% and 97.3% for the extracts, with $IC_{50}$ (median inhibitory concentration) values of $0.57{\pm}0.05\;mg/ml$ and $0.53{\pm}0.06\;mg/ml$, respectively. The inhibitory rates of the extracts against tyrosinase were 67.4% and 84.8%, respectively. The extracts were shown to reduce melanin formation in human melanoma cells. Melanin contents in the samples treated with 0.01% and 0.1% U. esculenta were 47.1% and 31.2%, respectively, and those treated with 0.01% and 0.1% Usnea longissima were 51.1% and 34.9%, respectively, whereas a value of 54.0% was registered when ascorbic acid was utilized as a positive control. In addition to direct tyrosinase inhibition, it was determined that the lichen extracts affected the activity of tyrosinase via the inhibition of tyrosinase glycosylation. As a result, the methanolic extracts of U. esculenta and Usnea longissima evidenced melanogenesis inhibitory effects, which occurred via multiple routes.

• 한국자원식물학회지
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• 제26권5호
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• pp.526-532
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• 2013

본 연구에서는 동해안에서 채집된 88종의 해조류에 대하여 미백제로서 응용 가능성을 알아보기 위해 멜라닌 생성에 미치는 영향을 in vitro 실험을 통해 알아보았다. Melan-a 세포에 해조류 추출물을 처리하여 멜라닌 양을 측정한 결과, 고리매, 미역쇠, 왜모자반, 감태, 톳추출물에서 멜라닌 생성이 감소되었으며, 특히 미역쇠추출물을 처리하였을 때 가장 유효하게 농도의존적으로 멜라닌 생성이 감소되었다. 멜라닌 생성 억제 효과가 tyrosinase 활성 저해와 관련 있는지를 확인한 결과, 약한 활성을 가지지만 직접 작용하여 활성을 저해하지는 않으면서, 세포 내의 tyrosinase 활성을 농도의존적으로 저해하였다. 이는 세포 내 tyrosinase 활성저해가 직접적이 아닌 다른 기전에 의해 일어난다는 것을 의미하며, 그 기전 중의 하나인 ${\alpha}$-glucosidase활성을 측정한 결과 농도의존적으로 활성을 저해하였으며, 세포 내 tyrosinase 활성 저해와 높은 상관도를 보임을 확인하였다. 즉 미역쇠추출물은 N-linked glycoprotein인 tyrosinase의 glycosylation을 억제하여 tyrosinase의 세포 내 이동이나 활성을 억제할 수 있음을 알 수 있었다. 결론적으로, 미역쇠추출물은 피부 미백에 유효한 활성을 나타내는 천연 유용자원으로 활용할 가치가 있는 것으로 사료된다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XIII)
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• pp.651-652
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• 2003

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XIII)
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• pp.649-650
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• 2003

• KSBB Journal
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• 제28권2호
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• pp.137-145
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• 2013

In order to develop new skin whitening agents, we prepared the $CH_2Cl_2$ layer (NGC) and BuOH layer (NGB) of 75% EtOH extract of the Nelumbinis nucifera Gaertner. We measured their tyrosinase inhibitory activity in vitro and melanin synthesis inhibitory activity in B16-F1 melanoma cells. They did not show inhibitory activity against mushroom tyrosinase but showed melanin synthesis inhibitory activity in a dose-dependent manner. In a melanin synthesis inhibition assay, NGC and NGB suppressed melanin production up to 52% and 46% at a concentration of $100{\mu}g/mL$, respectively. To elucidate the mechanism of the inhibitory effects of NGC and NGB on melanogenesis, we measured the expression of melanogenesis-related proteins by western blot assay. As a result, NGC suppressed the expression of tyrosinase, tyrosinase related protein 1 (TRP-1), tyrosinase related protein 2 (TRP-2), phosphorylated cAMP responsive element binding (p-CREB) protein, and microphthalmia associated transcription factor (MITF). And NGB inhibited the protein expression of tyrosinase and MITF, but had no significant effect on TRP-1, TRP-2, and p-CREB expression. Moreover, NGB increased the expression of phosphorylated extracellular signal-regulated kinase (p-ERK). In addition, we examined the inhibitory effect on the glycosylation of tyrosinase. As a result, NGC and NGB inhibited the activity of ${\alpha}$-glucosidase in vitro and the glycosylation of tyrosinase in B16-F1 melanoma cells. From these results, we concluded that NGC and NGB could be used as active ingredients for skin whitening.