• Journal of Microbiology
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• v.37 no.2
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• pp.97-101
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• 1999

Random hexapeptide library on the surface of filamentous bacteriophage was constructed using the SurfZAP vector. The size of the library was approximately 105. The peptide insert was flanked by two cysteines to constrain the peptide structure with a disulfide bond. This library was screened for the topoisomerase II binding peptide. Dramatic enrichment of the fusion phage over the VCS M13 helper phage was demonstrated by bio-panning affinity selection.

• Bulletin of the Korean Chemical Society
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• v.34 no.7
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• pp.2187-2190
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• 2013

• Journal of the Korean Applied Science and Technology
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• v.31 no.1
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• pp.120-129
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• 2014

The structure and physiological function of human skin continuously weaken due to growing older. The reasons of aging from external conditions are long term exposure to sun, wind, heat, cigarette smoke, and etc. This also palmitoyl oligopeptide or ceramide oligopeptide are known asc ingredient stimulating collagens and have the effect of reproducing the upper level of skin. Acetyl hexapeptide is an ingredient that makes the skin and muscle suppler and reduces wrinkles. It is a major high function beauty ingredient that substitutes botox. After dividing 7%, 14%, and 20% Acetyl hexapeptide experimental groups as groups A, B, and C the control group and experiment groups' change of wrinkles, hair follicles, moisture content, and dead skin cells was analyzed. According to the results, Acetyl hexapeptide seems to affect wrinkles, hair follicles and moisture content contrasting to the control group. Experimental groups and control group showed similar change in dead skin cells. In contrast to the control group satisfaction of examines was affected in wrinkles, hair follicles and moisture but removing dead skin cells had similar result in experimental groups and control group.

• BMB Reports
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• v.28 no.3
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• pp.197-203
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• 1995

Famesyl protein transferase involved in the first step of post-translational modification of $p21^{ras}$ proteins transfers the famesyl moiety from famesyl pyrophosphate to a cysteine residue in $p21^{ras}$ proteins. The enzyme was first purified 30,000-fold from bovine testis by use of 30~50% ammonium sulfate fractionation, DEAE-Sephacel ion exchange chromatography, Sephacryl S-300 gel filtration chromatography, Sephacryl S-200 gel filtration chromatography, and hexapeptide (Lys-Lys-Cys-Val-Ile-Met) affinity chromatography. The molecular weight of the purified enzyme was estimated to be ~100 kDa by gel filtration and SDS-polyacrylamide gels showed two closely spaced bands of ~50 kDa protein. These indicate that the enzyme consists of two nonidentical subunits, a and 13, which have slightly different molecular weights. The enzyme was inhibited by hexapeptide (Lys-Lys-Cys-Val-Ile-Met), which acted as an alternative substrate that competed for famesylation. Kinetic analysis by measuring initial velocities showed that famesyl protein transferase is a very slow enzyme. EDTA-treated famesyl protein transferase showed little activity with $Mg^{2+}$ or $Zn^{2+}$ alone, but required both $Mg^{2+}$ and $Zn^{2+}$ for the catalytic activity.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.46 no.1
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• pp.11-22
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• 2020

In this study, we investigated anti-pigmentation effect of a hexapeptide. The peptide significantly reduced melanin contents and inhibited tyrosinase activity in a dose-dependent manner, in which tyrosinase is a key enzyme in melanogenesis. The peptide also significantly reduced the expression levels of tyrosinase (TYR), tyrosinase-related protein 1 (TYRP1) and their upstream transcription factor, microphthalmia-associated transcription factor (MITF). Furthermore, the peptide suppressed the phosphorylation level of cAMP-response element binding protein (CREB), a transcription factor of MITF, and increased the phosphorylation level of extracellular signal-regulated kinase (ERK), a kinase mediates MITF phosphorylation and proteasomal degradation. The peptide significantly inhibited the expression of Rab27A, Melanophilin, and MyosinVa, the components of motor complex involved in intracellular movement of melanosome. These results suggest that Hexapeptide could be used as an effective whitening agent that has inhibitory effect on melanin production and melanosome transport by regulating expression and degradation of MITF in melanocytes.

• The Plant Pathology Journal
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• v.33 no.1
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• pp.87-94
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• 2017

Citrus canker disease decreases the fruit quality and yield significantly, furthermore, emerging of streptomycin-resistant pathogens threatens the citrus industry seriously because of a lack of proper control agents. Small synthetic antimicrobial peptides (AMPs) could be a promising alternative. Fourteen hexapeptides were selected by using positional scanning of synthetic peptide combinatorial libraries. Each hexapeptide showed different antimicrobial spectrum against Bacillus, Pseudomonas, Xanthomonas, and Candida species. Intriguingly, BHC10 showed bactericidal activity exclusively on Xanthomonas citri subsp. citri (Xcc), while BHC7 was none-active exclusively against two Pseudomonas spp. at concentration of $100{\mu}g/ml$ suggesting potential selectivity constrained in hexapeptide frame. Three hexapeptides, BHC02, 06 and 11, showed bactericidal activities against various Xcc strains at concentration of $10{\mu}g/ml$. When they were co-infiltrated with pathogens into citrus leaves the disease progress was suppressed significantly. Further study would be needed to confirm the actual disease control capacity of the selected hexapeptides.

• Journal of the Korean Chemical Society
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• v.5 no.1
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• pp.33-37
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• 1961

We have shown that carboxy-peptidase destroys the biological activity of angiotensin octa-and deca-peptides. Since Proline occurs as the seventh amino acid from the amino end of the chain and since carboxypeptidase does not cleave proline from a peptid chain, it is evident that the heptapeptid H.asp-arg-val-tyr-ileu-his-pro.OH is formed by this hydrolysis. This peptide must then be biologically inactive. In order to determine whether the phenyl group of the C-terminal amino acid was the necessary requirement for biological activity of the octapeptide, $ala^8$ angiotensin octapeptide(amino acids of peptides numbered from amino end) was synthesized. For this synthesis the four dipeptides were prepared: carbobenzoxy-L-prolyl-L-alanine-P-nitrobenzyl-ester, m.p. $134-135^{\circ}C,$ carbobenzoxy-L-isoleucyl-imidazole benzyl-L-histidine methyl ester, m.p. $114-116^{\circ}C,$ carbobenzoxy-L-valyl-L-tyrosine hydrazide and carbobenzoxy B-benzyl-L-aspartyl-nitro-L-arginine. The first three dipeptides were obtained as crystalline compounds. Imidazole-benzyl-L-histidine was used in the hope that it would block the histidine imidazole against side reactions in steps subsequent to the formation of the C-terminal tetrapeptide. Also, it was through that the imidazole benzylated peptides would be easier to crystallize. This, however, was not the case. The tetrapeptide, carbobenzoxy-L-isoleucyl-L-im, benzyl-histidyl, L-prolyl-L-alanine-nitrobenzyl ester was not obtained in a crystalline form. Neither could the mono-or dihydrobromide of the tetrapeptide free base be induced to crystallize. Carbobenzoxy-L-valyl-L-tyrosine azide was condensed with the tetrapeptide free base to yield the protected hexapeptide; carbobenzoxy-L-valyl-L-tyrosyl-L-isoleucyl-L-im, benzyl, histidyl-L-Prolyl-L-alanine-nitrobenzyl ester. Upon removal of the carbobenzoxy group with hydrogen bromide in acetic acid an amorphous free base hexapeptide ester was obtained. This compound gave the correct C, H, N analysis and contained the six amino acids in the correct ratio. The octapeptide was obtained by condensing this hexapeptide with carbobenzoxy-B-benzyl-L-aspartyl-nitro, L-arginine using the mixed anhydride method of condensation. This amorphous product was proven to be homogenous by chromatography in two solvent systems and upon hydrolysis yielded the eight amino acids in correct ratio. The five protecting groups were removed from the octapeptide by hydrogenolysis over palladium black catalyst. Biological assay of the free peptide indicated that it possessed less than 0.1 per cent of both pressor and oxytocic activity of the phenylalanine8 angiotensin. This suggests that the phenyl group is a point of attachment between angiotensin and its biological receptor site.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.180-180
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• 1994

Farnesyl protein transferase는 Ras precursor의 C-terminal에 있는 cystein residue에 farnesyl group을 결합시키는 효소다. 이 효소를 bovine testis에서 30-50% ammonium sulfate fractionation, DEAE-sephacel ion exchange, Sephacryl s-300 gel filtration, hexapeptide(KKCVIM) affinity chromatography를 통해 30000배로 분리하였다. 분리된 효소는 gel filtration시 약 100kDa으로, SDS-polyacrylamide 전기영동시 50kDa의 인접한 두 bands로 나타났고 이것은 $\alpha$, $\beta$ subunits으로 생각되었다. $\alpha$ subunit을 encoding하는 RAM2 유전자를 site directed mutagenesis로 145번의 histidine을 aspartate로, 140번의 aspartate를 asparagine 으로 바꾸었더니 optimal pH와 $K_{m}$ 값이 변했다. Diethyl pyrocarbonate로 histidine residues를 chemical modification시켰을때 효소의 활성이 저하되었다. 145번 histidine이 aspartate로 바뀐 돌연변이효소에서 비교적 느리게 활성이 저하되므로 145번 histidine이 이 효소의 active site에 있을것으로 추측된다.

• Animal cells and systems
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• v.12 no.1
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• pp.35-39
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• 2008

Menadione induced cell death in cultured C2 myoblasts. By screening synthetic peptide libraries composed of random sequence of hexapeptides, we identified the hexa-peptides pool of(Ala/Ile)-(Ile/Met)-Val-Ile-Asp-(Met/Ser)-$NH_2$ that protected the myoblasts against menadioneinduced cell death. Pre-incubation with the hexapeptide pool reduced the number of cells detached from culture dish substrate and increased the ratio of relative viability against menadione. In addition, the peptides strongly increased the expression of Bcl-2, an anti-apoptotic protein. These results suggest that the hexapeptides might enhance the resistance to cell death against menadione by increasing the expression of Bcl-2.

• Proceedings of the Korea Crystallographic Association Conference
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• 2003.05a
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• pp.14-14
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• 2003

We have crystallized and determined the structures o the Shank PDZ domain, alone and in complex with the synthetic C-terminal hexapeptide of GKAP protein at resolutions of 1.8Å and 2.5Å, respectively. The structure revealed the structural basis of the ligand recongition by Class I PDZ-ligand interaction. Moreover, dimeric structureof shank PDZ domain suggests that the βA strand is a common surface for dimerization of PDZ domains.