• Bulletin of the Korean Chemical Society
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• v.20 no.9
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• pp.1073-1077
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• 1999

CRAMP, a 37-amino acid cationic antimicrobial peptide was recently deduced from the cDNA cloned from mouse femoral marrow RNA. In order to investigate the structure-activity relationship and functional region of CRAMP, CRAMP and its 18-mer overlapping peptides were synthesized by the solid phase method. CRAMP showed broad spectrum antibacterial activity against both Gram-positive and Gram-negative bacterial strains (MIC: 3.125-6.25 μM) but had no hemolytic activity until 50 μM. CRAMP was found to have a potent anticancer activity (IC50: 12-23 μM) against two human small cell lung cancer cell lines. Furthermore, CRAMP was found to display faster bactericidal rate in B. subtilis rather than E. coli in the kinetics of bacterial killing. Among 18-meric overlapping fragment peptides, only CRAMP (16-33) displayed potent antibacterial activity (MIC: 12.5-50 μM) against several bacteria with no hemolytic activity. Circular dichroism (CD) spectra anal-ysis indicated that CRAMP and its analogues will form the amphipathic α-helical conformation in the cell membranes similar to other antimicrobial peptides, such as cecropins and magainins.

• Journal of Radiation Industry
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• v.7 no.2_3
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• pp.191-200
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• 2013

In this study, a novel bombesin (BBN) analogues, DOTA-Ala($SO_3H$)-4 aminobenzoyl-Gln-Trp-Ala-Val-Gly-His-Leu-Met-$NH_2$ (DOTA-sBBN) and DOTA-Lys(glucose)-4 aminobenzoyl-Gln-Trp-Ala-Val-Gly-His-Leu-Met-$NH_2$ (DOTA-gluBBN), were synthesized and radiolabeled, and their binding affinities were evaluated. Peptides were prepared by a solid phase synthesis method and their purities were over 98%. DOTA is the chelating agent for $^{177}Lu$-labeling, and the DOTA-conjugated peptides were radiolabeled with $^{177}Lu$ by a high radiolabeling yield (>98%). The Log P values of DOTA-sBBN and DOTA-gluBBN were -2.20 and -2.79, respectively. 50.41% of $^{177}Lu$-DOTA-sBBN and 72.97% of $^{177}Lu$-DOTA-gluBBN were left undegraded by the serum incubation at $37^{\circ}C$ for 48 hr. A competitive displacement of $^{125}I-[Tyr^4]$-BBN on the PC-3 human prostate carcinoma cells revealed that 50% inhibitory concentration ($IC_{50}$) were 1.46 nM of DOTA-sBBN and 4.67 nM of DOTA-gluBBN indicating a highly nanomolar binding affinity for GRPR. Therefore, it is concluded that $^{177}Lu$-DOTA-sBBN and $^{177}Lu$-DOTA-gluBBN can be potential candidates as a targeting modality for the Gastrin-releasing peptide receptor (GRPR)-over-expressing tumors, and further studies to evaluate their biological and pharmacological characteristics are needed.

• Journal of the Korean Applied Science and Technology
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• v.38 no.6
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• pp.1568-1576
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• 2021

Here, we conducted the study on the possibility of using FK-13, a short analog of human-derived antibacterial peptide LL-37, as a cosmetic preservative to discover a natural cosmetic preservative that is safe for human body. For the purpose, FK-13 composed of 13 amino acids was synthesized by solid-phase peptide synthesis, and purified using reversed phase-high performance liquid chromatography (RP-HPLC). The purity and molecular weight were confirmed by liquid chromatography-mass spectrometry (LC-MS) analysis. FK-13 showed high antimicrobial activity on the three gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis, and Staphylococcus epidermidis), the three gram-negative bacteria (Escherichia coli, Salmonella typhimurium, and Pseudomonas aeruginosa), and also even the fungus Candida glabrata. FK-13 had a broad spectrum of antibacterial activity, showing a suitability as a cosmetic preservative. In addition, FK-13 showed high thermostability and higher antibacterial activity in a comparative test with existing natural herbal cosmetic and chemical preservatives. Therefore, as FK-13 is a safe material and has high antibacterial activity at a low concentration, it is likely to be applied as a peptide natural cosmetic preservative that can replace existing chemical preservatives.

• BMB Reports
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• v.35 no.2
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• pp.239-243
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• 2002

Angiotensin I that converts the enzyme (ACE) inhibitory peptide, Gly-Pro-Leu, previously purified and identified from the Alaskan pollack skin gelatin hydrolysate, were synthesized. In addition, the peptides Gly-Leu-Pro, Leu-Gly-Pro, Leu-Pro-Gly, Pro-Gly-Leu, Pro-Leu-Gly, Gly-Pro, and Pro-Leu, which consisted of glycine, proline, and leucine, were synthesized by the solid-phase method. The $IC_{50}$ values of each tripeptide - namely Leu-Gly-Pro, Gly-Leu-Pro, Gly-Pro-Leu, Pro-Leu-Gly, Leu-Pro-Gly, and Pro-Gly-Leu - were 0.72, 1.62, 2.65, 4.74, 5.73, and $13.93{\mu}M$, respectively. The ACE inhibitory activity of these tripeptides was higher than that of dipeptides, such as Gly-Pro and Pro-Leu with $IC_{50}$ values of 252.6 and $337.3\;{\mu}M$, respectively. Among the tripeptides, Leu-Gly-Pro and Gly-Leu-Pro had higher inhibitory activity than Gly-Pro-Leu that was isolated from the Alaskan pollack skin gelatin hydrolysate. Among the different types of tripeptides that were examined, the highest ACE inhibitory activity was observed for Leu-Gly-Pro. It had the leucine residue at the N-terminal and proline residue at the C-terminal.

• Journal of Life Science
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• v.8 no.4
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• pp.395-399
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• 1998

Neurokinin A(NKA) and its derivatives ([Nle$^{7}$NKA,[Leu$^{7}$NKA] were synthesized by solid phase peptide synthesis method using Fmoc-TFA strategy and their smooth muscle contractile activities were measured to examine the structural effect of alkyl group at the 7th amino acid NKA on the smooth muscle contractile activity. The smooth muscle contractile activity. The smooth muscle contractile activities of [Nle$^{7}$]NKA and [Leu$^{7}$]NKA were only 5.64% and 1.55%, respectively when compared with NKA. This result suggested that the more three dimensional structure of th 7th amino acid as well as the whole message segment of NKA would be necessary to show the biological activity.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.11a
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• pp.4-4
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• 2012

Proteins enable biology to be viable through molecular interactions (such as in antigen-antibody, ligand-receptor, and drug-target) with

• Journal of the Korean Magnetic Resonance Society
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• v.7 no.1
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• pp.46-54
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• 2003

We synthesized a contrast agent for MRI that is capable of binding to the ABP-1 receptor and enhancing the contrast of the targeted cells. We used a lysine dendrimer (G=3)DTPA[Gd] as the contrast agent and synthesized a biotinylated polyclonal antibody for ABP-1 as the first antibody. Lysine dendrimers were prepared using the solid phase peptide synthesis method.$^3$ Amino-terminated lysine dendrimers were then coupled to DTPA using the anhydride method. Gd was complexed with the DTPA-lysine dendrimer in an acidic solution of 3 eq GdCl$_3$ to one of DTPA. The lysine dendrimer-DTPA[Gd] and avidin were conjugated in MES solution, pH 6.0, using EDC as the coupling reagent. The biotin-avidin system was used to link the polyclonal antibody and contrast agent. K562 cells were used for imaging.

• KSBB Journal
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• v.26 no.6
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• pp.483-490
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• 2011

Bioactive peptides (BAP) showed excellent cosmetic activity than bio-materials such as caffeic acid (CA), gallic acid (GA), and nicotinic acid (NA). Caffeoyl tripeptide-1 (CT-1) is a BAP that is stabilized with Gly-His-Lys (GHK) tripeptide and CA by using Fmoc solid phase peptide synthesis. Digalloyl tetrapeptide-19 (DT-19) is stabilized by combining Lys-Glu-Cys-Gly with GA and nicotinoyl tripeptide-1 (NT-1) is synthesized by GHK and NA. According to experiments, CT-1 has an excellent anti-oxidant function even with a very small amount of 10 ppm CT-1. DT-19's tyrosinase inhibition activity has the better effect of about 28.57% in 0.01% and 33.33% in 0.005% of concentration and about 7.89% in 0.001% concentration than vitamin-C. In addition, NT-1 is safer than the NA. Almost BAPs like pal-KTTKS, acetyl hexapeptide, and copper tripeptide-1 have the anti-wrinkle effect while DT-19 and NT-1 are applicable for potential BAPs focused on the whitening effect. The three kinds of BAPs like CT-1, DT-19, and NT-1 consisting of amino acids are safe to the skin, and have more excellent stability than bio-materials which are found to be unstable and cause skin irritation. Due to the high biological activity of BAP in the field of skin care, its utilization will increase constantly.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2001.06a
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• pp.149-153
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• 2001

To investigate the mode of bactericidal action for antimicrobial peptide, pediocin, synthetic and mutant pediocins were prepared by direct chemical synthesis. Native pediocin was purified from Pedio-coccus acidilactici M and its conformational structure and bactericidal functions were analyzed and compared to synthetic pediocin. Schematic mode of pediocin actions, how pediocin binds on the target cell membrane, penetrates and makes tunnel are proposed. For these purposes, primary and secondary structures of pediocin was analyzed and disulfide bond assignment was also done. The pediocin purified from P. acidilactici M had high effective bactericidal ability against gram positive bacteria, especially Listeria monocytogenes and was very stable at extreme pHs and even at high temperatures such as autoclaving temperature (121$^{\circ}C$). Pediocin was consisted of 44 amino acids with four cysteines. Novel synthetic peptides were achieved by solid phase peptide synthesis(SPPS) method. To explain the function of cysteine in C-terminal region, mutant pediocin, Ped[C24A＋C44A], was synthesized and their structural and biological functions were analyzed. Second mutant pediocin, Ped[KllE], was prepared to explain the function of lysine at 11 of N-terminal part of pediocin, especially loop of $\beta$-sheet, and to predict the initial binding site of pediocin. The native and synthetic pediocins was showed random coil conformation by spectropolarimetry in moderate conditions. This conformation was observed in extreme conditions such as high temperature and low and high pHs, also. Circular dichroism(CD) data also showed the existence of $\beta$-turn structure in N-terminal part both native and synthetic pediocins. A structural model for pediocin predicts that 18 amino acids in the N-terminal part of the peptide assume a three-strand $\beta$-sheet conformation. This random coil in C-terminal part of pediocin was converted to folding structure, helix structure, in nonpolar solvents such as alcohol and TFE. The disulfide bond between $^{9}$ Cys and $^{14}$ Cys was concrete and inevitable, however, evidences of disulfide bond between $^{24}$ Cys and $^{44}$ Cys was not. Data of Ped[C24A＋C44A], pediocin mutant showed that $^{44}$ Cys was required during killing the target cells but not inevitable, since Ped[C24A＋C44A] still have bactericidal activity but much less than native pediocin. Another pediocin mutant, Ped[KllE], had still bactericidal activity, was controversial to propose that positive charge like as $^{11}$ Lys in loop or hinge in bacteriocin bound or helped to binding to microorganism with electrostatic interaction between cell membrane especially teichoic acid and positive amino acid nonspecifically. The conformation of pediocin among native, synthetic and mutant pediocins did not show big difference. The conformations between oxidized and reduced pediocin were almost similar regardless of native or synthetic.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.62-70
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• 2018

In this study, we synthesized Oligo Peptide (Lys-Val-Ala-Arg-Pro: KVARP) and peptide derivatives using Solid Phase Peptide Synthesis(SPPS). KVARP was commonly known to improve whitening of skin. We measured bio-activity of the synthesized compounds. The whitening effect was measured in tyrosinase inhibition and the result showed to be highly effective with 93% inhibition rate at $5000{\mu}g/m{\ell}$ of Geranic-KVARP, on the other hand the IC50 value was $68{\mu}g/m{\ell}$. The wrinkle-reducing effect was measured by elastase inhibition at a concentration of 63% at $400{\mu}g/m{\ell}$ of Salicylic-KVARP, and the IC50 value was $253{\mu}g/m{\ell}$. In the DPPH assay, Caffeic-KVARP showed more than 95% antioxidant activity at $400{\mu}g/m{\ell}$ with high concentration and IC50 value was $31{\mu}g/m{\ell}$. The anti-inflammatory effect of Nitric Oxide inhibition was 67% at $400{\mu}g/m{\ell}$ of Lipoic-KVARP. Therefore, the four types of KVARP derivative that were synthesized from various experiments has shown that it could have potential to be used to develop new medicines, cosmetics as well as in various industries.