• 한국자기공명학회논문지
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• 제23권1호
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• pp.26-32
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• 2019

${\alpha}B$-crystallin (${\alpha}BC$) is a member of a small heat-shock protein (sHSP) superfamily and plays a predominant role in cellular protein homeostasis network by rescuing misfolded proteins from irreversible aggregation. ${\alpha}BC$ assembles into dynamic and polydisperse high molecular weight complexes containing 12 to 48 monomers; this variable stereochemistry of ${\alpha}BC$ has been linked to quaternary subunit exchange and its chaperone activity. The chaperone activity of ${\alpha}BC$ poses great potential as therapeutic agents for various neurodegenerative diseases. In this mini-review, we briefly outline the recent advancement in structural characterization of ${\alpha}BCs$ and its potential role to inhibit protein misfolding and aggregation in various human diseases. In particular, nuclear magnetic resonance (NMR) spectroscopy and its complimentary techniques have contributed much to elucidate highly-dynamic nature of ${\alpha}BCs$, among which notable advancements are discussed in detail. We highlight the importance of resolving the structural details of various ${\alpha}BC$ oligomers, their quaternary dynamics, and structural heterogeneity.

• Journal of Ginseng Research
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• 제32권1호
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• pp.73-78
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• 2008

Red ginseng acidic polysaccharide (RGAP), isolated from Korean red ginseng (Panax ginseng C.A. Meyer), has been shown to have a variety of biological functions such as immunostimulating and anti-tumor activities. In the present study, we investigated whether RGAP inhibited ligand-induced platelet aggregation. The washed platelet-rich plasma was prepared from male SD rats with successive centrifugation. The platelets $(10^8/ml)$ were preincubated with 1 mM of $CaCl_2$ for 2 min either in the presence or in the absence of RGAP $(10{\sim}50\;{\mu}g/ml)$ and were stimulated with collagen (2.5 ${\mu}g/ml$) and thrombin (0.1 U/ml). RGAP dose-dependently inhibited thrombin-induced platelet aggregation with $IC_{50}$ value of $26.2{\pm}2.0$ ${\mu}g/ml$. In collagen-induced platelet aggregation, RGAP inhibited the reaction with an $IC_{50}$ value of $31.5{\pm}3.0\;{\mu}g/ml$. RGAP potently suppressed the intracellular calcium ion, which was stimulated by thrombin (0.1 U/ ml). Among mitogen-activated protein kinase (MAPK) subtypes, the extracellular signal-regulated kinase (ERK) 1/2 and p38 MAPK were analyzed in the present study. RGAP inhibited the phosphorylation of ERK2 and p38 MAPK, which was activated by collagen (2.5 ${\mu}g/ml$). Finally, these results suggested that besides saponin fraction, RGAP take an important role in the preventive effect of Korean red ginseng against cardiovascular disease such as thrombosis and atherosclerosis.

• 대한수의학회지
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• 제55권4호
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• pp.233-240
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• 2015

Although the effects of the rice bran have recently been investigated, there is no information regarding platelet physiology available. However, it is well known that fermented natural plants have a beneficial effect on cardiovascular diseases. Therefore, this study was conducted to investigate whether fermented rice bran extract (FRBE) with several plants (Artemisia princeps, Angelica Gigantis Radix, Cnidium officinale, and Camellia sinensis) affected agonist-induced platelet aggregation, and if so, what the underlying mechanism of its activity was. We performed several experiments, including in vitro platelet aggregation, intracellular calcium concentration and adenosine triphosphate release. In addition, the activation of integrin ${\alpha}_{II}b{\beta}3$ was determined using fibrinogen binding. Thrombus formation was also evaluated in vivo using an arterio-venous shunt model. The FRBE inhibited collagen-induced platelet aggregation in a concentration-dependent manner. FRBE significantly and dose dependently attenuated thrombus formation using rat arterio-venous shunt. FRBE suppressed the intracellular calcium mobilization in collagen-stimulated platelets. We also found that FRBE inhibited extracellular stimuli-responsive kinase 1/2, p38-mitogen-activated protein kinases and c-Jun N-terminal kinase phosphorylation. These results suggested that FRBE inhibited collagen-induced platelet aggregation, which was mediated by modulation of downstream signaling molecules. In conclusion, FRBE could be developed as a functional food against aberrant platelet activation-related cardiovascular diseases.

• Journal of Ginseng Research
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• 제41권1호
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• pp.96-102
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• 2017

Background: Korean ginseng, Panax ginseng Meyer, has been used as a traditional oriental medicine to treat illness and promote health for several thousand years. Ginsenosides are the main constituents for the pharmacological effects of P. ginseng. Since several ginsenosides, including ginsenoside (G)-Rg3 and G-Rp1, have reported antiplatelet activity, here we investigate the ability of G-Rp4 to modulate adenosine diphosphate (ADP)-induced platelet aggregation. The ginsenoside Rp4, a similar chemical structure of G-Rp1, was prepared from G-Rg1 by chemical modification. Methods: To examine the effects of G-Rp4 on platelet activation, we performed several experiments, including antiplatelet ability, the modulation of intracellular calcium concentration, and P-selectin expression. In addition, we examined the activation of integrin ${\alpha}IIb{\beta}_3$ and the phosphorylation of signaling molecules using fibrinogen binding assay and immunoblotting in rat washed platelets. Results: G-Rp4 inhibited ADP-induced platelet aggregation in a dose-dependent manner. We found that G-Rp4 decreased calcium mobilization and P-selectin expression in ADP-activated platelets. Moreover, fibrinogen binding to integrin ${\alpha}IIb{\beta}_3$ by ADP was attenuated in G-Rp4-treated platelets. G-Rp4 significantly attenuated phosphorylation of extracellular signal-regulated protein kinases 1 and 2, p38, and c-Jun N-terminal kinase, as well as protein kinase B, phosphatidylinositol 3-kinase, and phospholipase C-${\gamma}$ phosphorylations. Conclusion: G-Rp4 significantly inhibited ADP-induced platelet aggregation and this is mediated via modulating the intracellular signaling molecules. These results indicate that G-Rp4 could be a potential candidate as a therapeutic agent against platelet-related cardiovascular diseases.

• Journal of Plant Biology
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• 제20권4호
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• pp.151-155
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• 1977

Ultrastructural changes of the protein bodies in Glycine max during early germination were studied. There were no major morphological changes in protein bodies within 3 days after the imbibition, but from the 4th day the expanse of protein bodies could be observed. In subsequent stages, the aggregation of protein bodies coalesced into a large mass and then less electron-dense material in the central part of the cell. At last it bacame highly vacuolated.

• 생명과학회지
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• 제11권1호
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• pp.43-47
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• 2001

A mutant tryptophan synthase $\alpha$-subunit, where Pro28 was replaced with Leu, tends to be expressed in recombinant E. coli. CD and fluorescence spectra of this protein indicate some changes in secondary and tertiary structure. Wild type protein was more or less affected by {TEX}$Ca^{2+}${/TEX} ion in regards of the fluorescent properties of its native, unfolded and intermediate forms, but the mutant protein was not at all. The dramatic structural changes may be related to the aggregation of this mutant protein.

• Journal of Chest Surgery
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• 제36권9호
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• pp.666-673
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• 2003

폐암의 주된 원인으로 알려진 흡연은 그 악성세포 발현기전이 아직 정확히 규명된 바 없다. 이에 저자들은 흡연에 의한 발암성의 지표로 흡연 중에 특이적으로 존재하는 강력한 발암물질인 NNK(4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone)를 이용하여 흡연에 따른 폐암의 발생과 그 Protein kinase C (PKC) isoform과 관련된 기전에 관한 연구를 시도하였다. 대상 및 방법: 인체 상피세포를 NNK에 노출시킨 후 saturation density, soft agar colony formation, cell aggregation 및 foci의 출현 등의 양상을 파악하여 세포 발암성 여부를 관찰하였으며 NNK를 15분간 노출시킨 후 PKC의 변화는 세포 내 PKC isoform의 양을 cytosolic fraction과 membrane fraction으로 분리하여 측정하여 분석하였다. 결과: NNK 투여군에서 saturation density, soft agar colony formation, cell aggregation 및 foci의 출현 시기 등의 세포 발암성을 뚜렷이 나타내었으며 PKC isoform분석의 경우 PKC-$\alpha$의 membrane fraction의 뚜렷한 증가를 보였으며 이러한 활성은 용량-의존적인 형태를 유지하였다. PKC-$\varepsilon$은 NNK 처리 시 용량-의존적으로 cytosol fraction의 감소 및 membrane fraction의 증가를 뚜렷하게 보였고 NNK에 의한 PKC-λ의 변화는 감지되지 않았다. 결론: 본 연구는 화학적 발암물질인 NNK가 인체발암화에 관여함을 재차 확인하면서 초기 과정에 관여하는 PKC isoform의 변화를 분석함으로써 total PKC활성이 아닌 isoform 각각에 대한 변화를 확인하였다는 점에서 앞으로 인체상피세포 기원의 폐암 생성 기전 연구에 기여할 것으로 생각한다.

• 혜화의학회지
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• 제8권1호
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• pp.425-449
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• 1999

For the evaluation of the effect on SWS, experiments were made on hyperlipidemia induced by hypercholesterol diet, inhibitory reaction to human platelet aggregation, Pulmonary thrombosis induced by collagen and epinephrine, global cerebral ischemia induced by KCN, brain ischemia induced by MCA occlusion, cytotoxicity of PC12 cells induced by amyloid ${\beta}$ protein(25-35), and NO production in RAW cells stimulated by lipopolysaccharide. The results were obtained as follows : 1. In the experiment on hyperlipidemia, the level of serum total cholesterol, phospholipid, and LDL-cholesterol were significantly decreased while the level of triglyceride, VLDL-cholesterol, and HDL-cholesterol had no significant change. 2. In the experiment on inhibitory reaction to platelet aggregation, SWS inhibited platelet aggregation induced by ADP(36.05%), by collagen(20.4%), and by thrombin(0.6%). 3. In the experiment on pulmonary thrombosis induced by collagen and epinephrine, the protective effect was found(37%). 4. In the experiment on global cerebral ischemia, coma duration induced by KCN changed insignificantly. 5. In the experiment on MCA occlusion, the change of neurologic grades on hind limb was significant only after the operation. Besides brain ischemic area and edema ratio were significantly decreased. 6. In the experiment on cytotoxicity of PC 12 cells induced by amyloid ${\beta}$ protein, the significant protective effect was found as concentration increases. 7. In the experiment on NO production in RAW cells stimulated by lipopolysaccharide, NO was significantly decreased. According to the results, it is expected that SWS might be effective on hyperlipidemia and brain damage.

• 한국발생생물학회지:발생과생식
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• 제18권4호
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• pp.213-224
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• 2014

Previously we have shown that human abdominal adipose derived-stem cells (ADSCs) could aggregate during the high-density culture in the presence of human serum (HS). In the present study, we observed that human cord blood serum (CBS) and follicular fluid (HFF) also induced aggregation. Similarly, porcine serum could induce aggregation whereas bovine and sheep sera induced little aggregation. qRT-PCR analyses demonstrated that, compared to FBS-cultured ADSCs, HS-cultured cells exhibited higher level of mRNA expression of CLDN3, -6, -7, -15, and -16 genes among the tight junction proteins. ADSCs examined at the time of aggregation by culture with HS, BSA, HFF, CBS, or porcine serum showed significantly higher level of mRNA expression of JAM2 among JAM family members. In contrast, cells cultured in FBS, bovine serum or sheep serum, showed lower level of JAM2 expression. Immunocytochemical analyses demonstrated that the aggregates of HS-cultured cells (HS-Agg) showed intense staining against the anti-JAM2 antibody whereas neither non-aggregated cells (HS-Ex) nor FBS-cultured cells exhibited weak staining. Western blot results showed that HS-Agg expressed JAM2 protein more prominently than HS-Ex and FBS-cultured cells, both of latter reveled weaker intensity. These results suggest that the aggregation property of ADSCs during high-density culture would be dependent on the specific components of serum, and that JAM2 molecule could play a role in the animal sera-induced aggregation in vitro.

• 한국환경보건학회지
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• 제30권4호
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• pp.314-319
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• 2004

Glycinin of more than $97\%$ purity was modified using maleic anhydride. Glycinin samples of $0\%,\;65\%,\;and\;95\%$ lysine residue modifications were used to determine the changes in turbidimetric characteristics of the protein due to maleylation. The solubility behavior of the protein as a function of pH was changed with maleylation. The isoelectric point of $65\%\;and\;95\%$ modified glycinin shifted to pH 4.0 and pH 3.5-4.0, respectively, as compared to pH 4.6 for native glycinin. Maleylated glycinins exhibited increased solubility at pH above 4.6. Turbidity of native glycinin decreased substantially by the addition of NaCl, but the stabilizing effect of NaCl decreased when the protein was chemically modified. The effect of NaCl on $65\%$ modified glycinin was intermediate between native glycinin and $95\%$ modified sample. Thermal aggregation of native glycinin was completed within 5 min of heating at $80^{\circ}C$. Maleylation contributed significantly to the thermostability of the protein at pH of 7.0 and 9.0, exhibiting little turbidity. Addition of NaCl suppressed thermal aggregation of native glycinin, but turbidity actually increased for the samples of $65\%\;and\;95\%$ modification.