• BMB Reports
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• v.32 no.6
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• pp.561-566
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• 1999

CA(1-8)-ME(1-12) [CA-ME], composed of cecropin A(1-8) and melittin(1-12), is a synthetic antimicrobial peptide having potent antibacterial and antitumor activities with minimal hemolytic activity. In order to investigate the effects of the flexible hinge sequence, Gly-Ile-Gly, of CA-ME on antibiotic activity, CA-ME and three analogues, CA-ME1, CA-ME2, and CA-ME3, were synthesized. The Gly-Ile-Gly sequence of Ca-ME was deleted in CA-ME1 and replaced with Pro and Gly-Pro-Gly in CA-ME2 and CA-ME3, respectively. CA-ME1 and CA-ME3 showed a significant decrease in antitumor activity and phospholipid vesicle-disrupting ability. However, CA-ME2 showed similar antitumor and vesicle-disrupting activities, as compared with CA-ME. These results suggest that the flexibility or ${\beta}$-turn induced by Gly-Ile-Gly or Pro in the central part of CA-ME may be important in the electrostatic interaction of the N-terminus cationic ${\alpha}$-helical region with the cell membrane surface and the hydrophobic interaction of the C-terminus amphipathic ${\alpha}$-helical region with the hydrophobic acyl chains in the cell membrane. CA-ME3 exhibited lower antitumor and vesicle-disrupting activities than CA-ME and CA-ME2. This result suggests that the excessive ${\beta}$-turn structure caused by the Gly-Pro-Gly sequence in CA-ME3 seems to interrupt ion channel/pore formation in the lipid bilayer. We concluded that the appropriate flexibility or bilayer. We concluded that the appropriate flexibility or ${\beta}$-turn structure provided by the central hinge is responsible for the effective antibiotic activity of the antimicrobial peptides with the helix-hinge-helix structure.

• Journal of Embryo Transfer
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• v.21 no.3
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• pp.247-253
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• 2006

본 연구는 안정된 돼지 체외 성숙 난자를 얻을 목적으로 배양액의 종류 및 배양액에 EGF, ${\beta}-ME$, 호르몬 첨가가 돼지 난포란의 체외 성숙에 미치는 영향을 조사하였다. 난포란을 TCM-199, NCSU-23 및 PZM-3으로 48시간 배양했을 때 체외 성숙율은 각각 $22.1{\pm}0.70%,\;30.6{\pm}0.70%$ 및 $30.4{\pm}2.82%$였다. TCM-199로 48시간 배양했을 때 체외 성숙율은 NCSU-23 및 PZM-3 보다 약간 낮은 체외 발생율을 나타냈다. 난포란을 25 ng/ml의 EGF를 첨가한 TCM-199, NCSU-23 및 PZM-3로 48시간 배양했을 때 체외 성숙율은 각각 $46.3{\pm}2.8%,\;76.6{\pm}3.1%$ 및 $72.2{\pm}2.6%$로 나타났다. 난포란의 배양 시 배양액에 25 및 50 ng/ml의 EGF를 첨가 후 48시간 배양했을 때 첨가하지 않은 군에 비해 높은 체외 성숙율을 나타냈다(p<0.05). 난포란을 NCSU-23 및 PZM-3 배양액에 $25{\mu}M/ml$의 ${\beta}-ME$를 첨가한 후 48시간 배양했을 때 체외성숙율은 각각 $43.9{\pm}1.41%,\;41.7{\pm}l.41%,\;44.4{\pm}0.70%,\;40.6{\pm}0.70%$로 나타났다. 난포란을 $25{\mu}M/ml$의 ${\beta}-ME$를 첨가한 NCSU-23로 48시간 배양했을 때 첨가하지 않은 군에 비해 높은 체외 성숙율을 나타냈다(p<0.05). 난포란의 배양 시 NCSU-23에 PMSG, hCG, PMSG+hCG, hCG+${\beta}$-estradiol, PMSG+${\beta}$-estradiol을 첨가 후 배양하였을 때 체외 성숙율은 각각 75.6%, 77.8%, 80.0%, 86.4% 및 84.8%로서 무첨가 군(64.4%)에 비해 높게 나타났다(p<0.05).

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.3
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• pp.317-324
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• 2004

The present study was conducted to investigate the involvement of nitric oxide (NO) in cumulus expansion, oocyte mortality and meiotic maturation of porcine cumulus enclosed oocytes (CEOs) cultured in two different models when gonadotropins, including follicle-stimulating hormone (FSH) and human chorionic gonadotropin (hCG) were presented or not. And the interaction between NO and $\beta$-mercaptoethanol ($\beta$-ME), a free radical scavenger was also investigated. Two models refer to spontaneous maturation model and hypoxanthine (HX) medium model. All the 3,433 eligible CEOs were incubated at $39^{\circ}C$ and the cumulus expansion, oocyte morphology and nuclear phase were evaluated 44 h after incubation. (1) In spontaneous maturation model, NO stimulates the cumulus expansion and $\beta$-ME delayed it. NO doesn't affect the oocyte meiotic resumption but inhibits the oocytes to develop to metaphase II. (2) In HX medium model, NO or $\beta$-ME doesn't affect the expansion in the absence of gonadotropins, but in the presence of gonadotropins, NO or $\beta$-ME inhibits the expansion. In the presence of gonadotropins, NO inhibits the oocyte meiotic resumption and it especially inhibits the oocyte to develop to metaphase II, and $\beta$-ME reverses such inhibitory effects. The cooperation of gonadotropins and $\beta$-ME stimulates the meiotic resumption and especially, promotes the CEOs to develop to metaphase II in both models. Moreover, HX might contribute to the fragility of oocyte zona pellucida and gonadotropins, nitric oxide and $\beta$-ME could alleviate it separately, and cooperatively. It is concluded that NO exerts different functions in two models and $\beta$-ME affected the functions of NO in different models.

• Journal of Embryo Transfer
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• v.32 no.1
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• pp.9-15
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• 2017

The present study was aimed to determine the effect of green tea extract (GTE) and beta-mercaptoethanol (${\beta}$-ME) supplementation in boar sperm freezing extender on sperm motility, viability and reactive oxygen species (ROS) level. Experimental groups were allocated into Lactose-egg yolk (LEY) without antioxidant (control), GTE (1,000 mg/L GTE in LEY) and ${\beta}$-ME ($50{\mu}M$ ${\beta}$-ME in LEY). Spermatozoa extended with LEY were cooled to $5^{\circ}C$ for 3 h and then kept at $5^{\circ}C$ for 30 min following dilution with LEY containing 9% glycerol and 1.5% Equex STM (final sperm concentration: $1{\times}10^8/mL$). Spermatozoa were loaded into straws and frozen in nitrogen vapor for 20 min. Following thawing at $37^{\circ}C$ for 25 sec, sperm viability and ROS level were measured using fluorescent double stain Fertility(R) and cytometry, respectively. Motility and viability of GTE supplemented-group were higher than those of control and ${\beta}$-ME without significance. ROS level in GTE group showed significantly lower than control (P < 0.05). In conclusion, GTE supplementation in boar sperm freezing extender can reduce ROS generation during freezing.

• Toxicological Research
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• v.29 no.4
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• pp.235-240
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• 2013

Extracellular accumulation of amyloid beta protein ($A{\beta}$) plays a central role in Alzheimer's disease (AD). Some metals, such as copper, lead, and aluminum can affect the $A{\beta}$ accumulation in the brain. However, the effect of mercury on $A{\beta}$ accumulation in the brain is not clear. Thus, this study was proposed to estimate whether mercury concentration affects $A{\beta}$ accumulation in PC12 cells. We treated 10, 100, and 1000 nM $HgCl_2$ (Hg) or $CH_3HgCl_2$ (MeHg) for 48 hr in PC12 cells. After treatment, $A{\beta}_{40}$ in culture medium increased in a dose- and time-dependent manner. Hg and MeHg increased amyloid precursor protein (APP), which is related to $A{\beta}$ production. Neprilysin (NEP) levels in PC12 cells were decreased by Hg and MeHg treatment. These results suggested that Hg induced $A{\beta}$ accumulation through APP overproduction and reduction of NEP.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.1
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• pp.35-41
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• 2009

This study was undertaken to evaluate how ${\beta}$-mercaptoethanol (bME), an exogenous antioxidant, interacts with preantral follicles cultured in vitro. Mouse primary or secondary follicles were cultured in glutathione (GSH)-free or GSH-containing medium supplemented with bME of various concentrations, and the growth of preantral follicles, the maturation of intrafollicular oocytes and preimplantation development after parthenogenesis were monitored. In experiment 1, 0, 25, 50 or 100 ${\mu}M$ bME was added to culture medium supplemented with 100 ${\mu}M$ GSH or not. When secondary follicles were cultured in GSH-free medium, no significant change in follicle growth was detected after bME addition. However, exposure to bME in the presence of GSH significantly inhibited both follicle growth and oocyte maturation. Such detrimental effect became prominent in primary follicles and bME strongly inhibited follicle growth in the absence of GSH. In conclusion, there are stage-dependent effects of bME on follicle growth and oocyte maturation, and selective use of antioxidants contributes to establishing an efficient follicle culture system.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.5
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• pp.615-621
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• 2002

We investigated the effects of the mitogen supplements of 3 types, pokeweed mitogen (PWM), phytohemagglutinin (PHA) and concanavalin A (ConA), to a whole blood culture system on the number of metaphase spreads obtained in perinatal bovine chromosome analysis. In addition, the supplementation of ${\beta}$-mercaptoethanol (${\beta}$-ME) and FBS was examined in such system. Significant differences (p<0.05) were seen in the number of metaphase spreads with PHA stimulation compared to both PWM and ConA stimulation. When examined the effects of ${\beta}$-ME supplementation, the number of metaphase spreads was significantly (p<0.05) increased at $30{\mu}M$ ${\beta}$-ME compared to control. When evaluated FBS supplementation during PWM stimulation, no significant effect of the supplementation was found. Finally, the effects of the cortisol concentration (10-20, 20-30 and >30 ng/ml) of the blood samples were examined. There was no significant effect of cortisol concentration (p>0.05) among these 3 cortisol concentration groups. The mean percentages of normal metaphase plates (2n=60) from each calf 1) with ${\beta}$-ME, 2) without ${\beta}$-ME and 3) with FBS stimulated with PWM were not significantly different (p>0.05). In conclusion, these findings may be useful in cytogenetic screening programs for not only perinatal calves but also for mature cattle.

• Bulletin of the Korean Chemical Society
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• v.32 no.spc8
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• pp.2955-2959
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• 2011

Second-order rate constants for nucleophilic substitution reactions of 2,4-dinitrophenyl benzenesulfonate 1a with a series of alicyclic secondary amines in MeCN have been measured spectrophotometrically and compared with those reported previously for the corresponding reactions performed in aqueous medium to investigate the effect of medium on reactivity and reaction mechanism. The amines employed in this study are found to be more reactive in the aprotic solvent than in $H_2O$. The reactions of 1a in MeCN result in a linear Br${\o}$nsted-type plot with ${\beta}_{nuc}$ = 0.58, which contrasts to the curved Br${\o}$nsted-type plot reported previously for the corresponding reactions performed in the aqueous medium (i.e., ${\beta}_2$ = 0.86 and ${\beta}_1$ = 0.38). Accordingly, it has been concluded that the reaction mechanism changes from a stepwise mechanism to a concerted pathway upon changing the medium from $H_2O$ to MeCN. Reactions of Y-substituted phenyl benzenesulfonates 1a-c with piperidine in MeCN result in a linear Br${\o}$nsted-type plot with ${\beta}_{lg}$ = -1.31, indicating that expulsion of the leaving group is significantly more advanced than bond formation in the transition state. The trigonal bipyramidal intermediate ($TBPy^{\pm}$) proposed previously for the reactions in $H_2O$ would be highly unstable in MeCN due to strong repulsion between the negative charge in $TBPy^{\pm}$ and the negative dipole end of MeCN. Thus, destabilization of $TBPy^{\pm}$ in MeCN has been concluded to change the reaction mechanism from a stepwise mechanism to a concerted pathway.

• YAKHAK HOEJI
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• v.51 no.2
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• pp.88-95
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• 2007

Atractylodes macrocephala has been used for renal anorexia, gastroenteritis, cold, dyspepsia in Korean folk medicine. Specially aerial parts has been eaten as edible mountain herbs. In order to investigate the efficacy of antioxidant activity the activity guided fractionation and isolation of physiologically active substance were peformed. For the investigation of the active components from Atractylodes macrocephala MeOH extracts of aerial parts of Atractylodes macrocephala Koidzumi L. were suspended with H$_2$O, partitioned by CHCl$_3$. In order to investigate the efficacy of antioxidative activity the activity guided fractionation and isolation of physiologically active substance were peformed. CHCl$_3$, H$_2$O, 30% MeOH, 60% MeOH, MeOH fractions were examined antioxidative activity by DPPH method. It was revealed that 30% MeOH and 60% MeOH fractions have significantly antioxidant activity. From 30% MeOH and 60% MeOH fraction, six flavonoids (7-methoxy-pinocembrin-7-O-${\beta}$-D-glucopyranoside, apige nin-8-C-${\beta}$-D-glucopyranoside, 4'-caffeoyl-luteolin-6-glucopyranoside, luteloin-6-C-${\beta}$-D-glucopyranoside, apigenin-6-C-${\beta}$-D-glucopyranoside, luteolin) and four phenylpropanoids (3-feruloylquinic acid, 4,5-di-O-caffeoylquinic acid, feruloyl acid, 3,5-di-O-caffeoylquinic acid) were isolated. To investigate the antioxidant activities of each compounds, we measured radical scavening activity with DPPH method and anti-lipid peroxidative efficacy on low density lipoprotein (LDL) with TBARS assay. Six compounds (III, IV, V, VI, IX, X) which have antioxidant factor showed significant activities.

• Microbiology and Biotechnology Letters
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• v.24 no.5
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• pp.529-533
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• 1996

Melittin (ME) from honeybee venom has a broad range of strong antimicrobial activity, but it has hemolytic activity against eukaryotic cells. In order to design peptides with powerful antifungal activity without cytotoxic property of ME and understand structure-antifungal activity relationships, the hybrid peptides derived from the sequences of ME and cecropin A (CA) or magainin 2 (MA), MA(10-17)ME(1-12) and CA(1-8)ME(1-12). were synthesized by solid phase method. MA(10-17)ME(1-12) showed potent antifungal activity comparable to ME against Fusarium oxysporum with no hemolytic activity against human red blood cells. The hybrid peptides showed strong inhibi- tion of (1, 3)-$\beta$-D-glucan synthase. This result indicates that the antifungal activity of the hybrid peptides against Fusarium oxysporum is attributed to the inhibition of cell wall synthesis. The results therefore showed a successful design of a peptide having antifungal activity without hemolytic property.