• YAKHAK HOEJI
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• v.58 no.1
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• pp.21-27
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• 2014

We have developed 8 peptide derivatives as potential MC1R antagonists and their inhibitory effects on ${\alpha}$-MSH induced cell growth in cultured normal human melanocytes (NHM) were investigated. From these experiments, the two most potent peptide derivatives, 5-phenylvaleric acid-(D)His-Arg-Trp-$(Lys)_6NH_2$ (P 6) and 5-phenylvaleric acid-(D)His-Arg-Trp-$(Lys)_9NH_2$ (P 7) were selected for further studies. In ${\alpha}$-MSH depleted NHM cells, we have found that the treatment with 1 ${\mu}M$ of these two peptide derivatives, P 6 and P 7, inhibited the cell proliferation induced by the addition of 1 nM ${\alpha}$- MSH by 70% and 72%, respectively. In NHM cells without previous ${\alpha}$-MSH depletion, 1 ${\mu}M$ treatment in the presence of 10 nM ${\alpha}$-MSH resulted in 70% (P 6) and 80% (P 7) decrease in cell growth and 64% (P 6) and 71% (P 7) reduction in melanin synthesis, respectively. The peptide derivatives P 6 and P 7 were proved to have no apparent cytotoxicity and inhibited the elevation of intracellular cAMP concentration triggered by ${\alpha}$-MSH. In conclusion, our data suggest that the peptide derivatives reported in this study, 5-phenylvaleric acid-(D)His-Arg-Trp-$(Lys)_6NH_2$ (P 6) and 5-phenylvaleric acid-(D)His- Arg-Trp-$(Lys)_9NH_2$ (P 7) strongly antagonize ${\alpha}$-MSH, inhibit cell proliferation and melanin synthesis, and lower the intracellular cAMP concentration, hence have a promising potential as a novel skin lightening agent.

• Bulletin of the Korean Chemical Society
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• v.31 no.9
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• pp.2537-2541
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• 2010

We chose a fluorescent pentapeptide sensor (-CPGHE) containing a dansyl fluorophore as a model peptide and investigated whether the selectivity and sensitivity of the peptides for heavy and transition metal ions could be tuned by changing amino acid sequence. In this process, we developed a selective peptide sensor, Cp1-d (-HHPGE, $K_d\;=\;670\;nM$) for detection of $Zn^{2+}$ in 100% aqueous solution and a selective and sensitive peptide sensor, Cp1-e (-CCHPGE, $K_d\;=\;24\;nM$) for detection of $Cd^{2+}$ in 100% aqueous solution. Overall results indicate that the selectivity and sensitivity of the metallopeptide sensors to specific heavy and transition metal ions can be tuned by changing amino acid sequence.

• Journal of Environmental Science International
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• v.12 no.1
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• pp.77-80
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• 2003

The interaction of mastoparan B, a cationic tetradecapeptide amide isolated from the hornet Vespa basalis, with phospholipid bilayers was studied with synthetic mastoparan B and its analogue with Ala instead of hydrophobic 12th amino acid residue in mastoparan B. MP-B and its derivative, [12-Ala]MP-B were synthesized by the solid-phase peptide synthesis method. MP-B and its analogue, [12-Ala]MP-B adopted an unordered structure in buffer solution. In the presence of neutral and acidic liposomes, the peptides took an $\alpha$-helical structure. The two peptides interacted with neutral and acidic lipid bilayers. These results indicated that the hydrophobic face in the amphipathic $\alpha$-helix of MP-B critically affected the biological activity and helical content.

• Bulletin of the Korean Chemical Society
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• v.9 no.6
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• pp.394-398
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• 1988

Unusually high reactivity was found in peptide bond formation between p-nitrobenzophenone oxime resin (I) ester and amino acid 4-(methylthio)phentyl (MTP) esters. A charge-transfer complex between the two phenyl rings of the oxime resin (I) and the incoming amino acid MTP esters was considered to be responsible to accelerate the aminolysis reaction of the peptide oxime resin ester. Several di-, tri-, and pentapeptide fragments for preparing enkephalin and glutathione oligomers were successfully prepared in short times.

• Molecules and Cells
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• v.24 no.1
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• pp.69-75
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• 2007

Alzheimer's disease is a neurodegenerative disorder associated with progressive loss of cognitive function and memory. Amyloid beta peptide ($A{\beta}$) is the major component of senile plaques and is known to exert its cytotoxic effect mainly by producing $H_2O_2$. Vascular endothelial growth factor (VEGF) is elevated in the cerebrospinal fluid (CSF) and brain of AD patients, and $H_2O_2$ is one of the factors that induce VEGF. Therefore, we tested whether $A{\beta}$ might be responsible for the increased VEGF synthesis. We found that $A{\beta}$ induced the production of $H_2O_2$ in vitro. Comparison of the amount of $H_2O_2$ required to induce VEGF synthesis in HN33 cells and the amount of $H_2O_2$ produced by $10{\mu}M\;A{\beta}_{1-42}$ in vitro suggested that a toxic concentration of $A{\beta}$ might induce VEGF synthesis in these cells. However, toxic concentrations of $A{\beta}$ failed to induce VEGF synthesis in several cell systems. They also had no effect on antioxidant enzymes such as glutathione peroxidase, catalase, and peroxiredoxin in HN33 cells. $Cu^{2+}$, $Zn^{2+}$ and $Fe^{3+}$ are known to accumulate in the brains of AD patients and promote aggregation of $A{\beta}$, and $Cu^{2+}$ by itself induces synthesis of VEGF. However, there was no synergistic effect between $Cu^{2+}$ and $A{\beta}_{1-42}$ in the induction of VEGF synthesis and $Zn^{2+}$ and $Fe^{3+}$ also had no effect on the synthesis of VEGF, alone or in combination with $A{\beta}$.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.45 no.3
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• pp.299-306
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• 2019

Ginseng berry (GB) contains Ginsenoside Re and has anti-inflammatory and anti-wrinkle properties. In this study, TLC fractions 1, 2, and 4 of the ginseng berry amino acid complex were identified and analyzed by HPLC. And identified a peptide (AP-1) by LC/MASS analysis of fraction 1. The anti-inflammatory activity was confirmed by investigating the inhibitory effect of AP-1 on NO production. In addition, collagen synthesis using procollagen type I C-peptide (PIP) ELISA kit was 50% higher effective than that of the control group. From these results, the peptide isolated from ginseng berry amino acid complex is considered to have anti-inflammatory and anti-wrinkle effect, and may be useful as an anti-inflammatory and anti-aging cosmetic raw material.

• Korean Journal of Microbiology
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• v.44 no.4
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• pp.271-276
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• 2008

Ribosome stalling by nascent sticky peptide has been reported in several organisms across the kingdom. To test whether small subunit (SSU) rRNA is involved in this phenomenon, we developed a genetic system that utilized the specialized ribosome system to isolate SSU rRNA mutants that enable ribosomes to bypass the SecM-derived sticky peptide in protein synthesis. In this system, CAT-SecM mRNA, which encodes CAT protein containing the sticky peptide derived from SecM, is only translated by specialized ribosomes. These ribosomes were shown to transiently stall on CAT-SecM mRNA followed by the synthesis of the sticky peptide. Expression of specialized ribosomes resulted in the decreased steady-state level of CAT-SecM mRNA, which is consistent with a notion that ribosome stalling induces mRNA degradation. Isolation and characterization of SSU rRNA mutations using this genetic system that are sufficient to circumvent ribosome stalling induced by the SecM-derived sticky peptide will provide evidence of SSU rRNA function in mRNA cleavage.

• Journal of the Korean Chemical Society
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• v.31 no.5
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• pp.457-463
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• 1987

The total synthesis of insulin A chain (1-21) with properly protected sulfhdryl groups of three cysteins for the correct intra and inter disulfide bond formation has been accomplished on 2-bromopropionylated 2% DVB-styreneresin support employing manually operated rotary vessel. The sulfhydryl groups of cysteins were protected with acetamidomethyl, benzyl, and benzhydryl respectively. Glutamine and asparagine were attached to the peptide chain by active ester coupling, all other amino acids were coupled with DCC/HOBT. The synthesized peptide was purified by DEAE Sephadex A-25 and gel filtration Sephadex LH-20. The final product was found to be homogeneous by HPLC, electrophoresis, and amino acid analysis. The overall yield of the pure isolated peptide was 6%.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.47 no.2
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• pp.147-153
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• 2021

Collagen hydrolysate (CH) is known to prevent skin aging by stimulating skin dermal fibroblasts to promote synthesis of extracellular matrix such as collagen and elastin. Recently, among the various factors that cause skin aging, advanced glycation end products (AGEs) have received particular attention. However, the effect of CH on AGE accumulation has not been studied. Since CH could affect AGE accumulation by promoting production of skin structural proteins, clinical trial was performed using low molecule collagen peptide (LMCP), which were CH containing 25% tripeptide and 4% Gly-Pro-Hyp. Skin autofluorescence (SAF) values were measured using an AGE reader to evaluate accumulation of AGE in skin. As a result of applying 0.5% and 1.0% LMCP solutions to the subject's forearm for 8 weeks, the SAF value at the test site significantly decreased compared to the control site. Additionally, in vitro test was performed using CCD-986sk to evaluate the promotion of collagen synthesis in skin fibroblasts by LMCP. As a result, 800 ㎍/mL of LMCP significantly increased synthesis of human pro-collagen Iα1 (COL1A1) in CCD-986sk. Through this study, we have confirmed that tropical LMCP applications can promote collagen synthesis to help anti-glycation effects, suggesting that LMCP has potential as an anti-aging cosmetic material.

• Journal of Microbiology and Biotechnology
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• v.11 no.4
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• pp.649-655
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• 2001

The kinetics of the thermolysin-catalyzed synthesis of N-(benzyloxycarbonyl)-L-phenylalanyl-L-leucine ethyl ester (Z-Phe-LeuOEt) from N-(benzyloxycarbonyl)-L-phyenylalanine (Z-Phe) and L-leucine ethyl ester (LeuOEt) in an ethyl acetate saturated aqueous system in a batch operation were studied. The kinetics for the synthesis of Z-Phe-LeuOEt were expressed using a rate equation for the rapid equilibrium random bireactant mechanism. The four kinetic constants involved in the rate equation were determined numerically by the quasi-Newton method so as to fit the calculated results with the experimental data. Within the pH and temperature range examined, the $K_{cat}$ value for the synthesis of Z-Phe-LeuOEt reached a maximum at pH 7.0 and $45^{\circ}C$, whereas the affinity between Z-Phe and thermolysin reached a maximum at pH 6.0 adn $40^{\circ}C$. The inhibitory effect of Z-Phe on the condensation reaction decreased as the pH and temperature decreased. In contrast, they affinity between LeuOEt and thermolysin remained unchanged within the pH and temperature range examined. Therefore, it was concluded that the protonation state of the carboxyl groups. of Z-Phe was more imprtant than that of the amono groups of LeuOEt for the synthesis of Z-Phe-LeuOEt in the present solvent system. The equilibrium yield at pH 6.0 and $30^{\circ}C$ was 8% higher than that at pH 7.0 and $40^{\circ}C$, although the rate was much slower. This result suggested that the affinity between the enzyme and the substrate rather than the overall rate was a more important factor affecting the equilibrium yield, when the peptide synthesis was carried out in a product-precipitation system.