• Journal of Microbiology and Biotechnology
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• v.22 no.4
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• pp.494-500
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• 2012

Silk fibroin (SF) peptide has been traditionally used as a treatment for flatulence, spasms, and phlegm. In this study, we examined whether SF peptide enhanced the anti-inflammatory effect of PEP-1-FK506 binding protein (PEP-1-FK506BP) through comparing the anti-inflammatory activities of SF peptide and/or PEP-1-FK506BP. In the presence or absence of SF peptide, transduction levels of PEP-1-FK506BP into HaCaT cells and mice skin and anti-inflammatory activities of PEP-1-FK506BP were identified by Western blot and histological analyses. SF peptide alone effectively reduced both mice ear edema and the elevated levels of cyclooxygenase-2, interleukin-6 and $-1{\beta}$, and tumor necrosis factor-${\alpha}$, showing similar anti-inflammatory effect to that of PEP-1-FK506BP. Furthermore, co-treatment with SF peptide and PEP-1-FK506BP exhibited more enhanced anti-inflammatory effects than the samples treated with SF peptides or PEP-1-FK506BP alone, suggesting the possibility that SF peptide and PEP-1-FK506BP might interact with each other. Moreover, the transduction data demonstrated that SF peptide did not affect the transduction of PEP-1-FK506BP into HaCaT cells and mice skin, indicating that the improvement of anti-inflammatory effect of PEP-1-FK506BP was not caused by enhanced transduction of PEP-1-FK506BP. Thus, these results suggest the possibility that co-treatment with SF peptide and PEP-1-FK506BP may be exploited as a useful therapy for various inflammation-related diseases.

• BMB Reports
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• v.44 no.4
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• pp.256-261
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• 2011

PEP-1 peptide has been used for transduction of native protein into mammalian cells. This work describes the findings that the fusion of PEP-1 to target proteins led to protein truncation likely in a non-protein-specific manner. Approximately 75% of PEP-1-MsrA fusion protein was truncated in the N-terminal region of MsrA between Lys-27 and Val-28 during expression in Escherichia coli and purification. This large protein truncation was also observed in another PEP-1 fused protein, PEP-1-MsrB2, in the N-terminal region of MsrB2. The full-length PEP-1-MsrA protein was rapidly transduced into keratinocyte cells within 15 min. The transduced PEP-1-MsrA was functionally active and could protect skin cells against oxidative stress- and ultraviolet radiation-induced cell death. Collectively, our data demonstrated the protective roles of MsrA in skin cells and, moreover, may raise a concern of protein truncation caused by fusion of PEP-1 about the general use of this peptide for protein transduction.

• Molecules and Cells
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• v.44 no.11
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• pp.830-842
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• 2021

When perceiving microbe-associated molecular patterns (MAMPs) or plant-derived damage-associated molecular patterns (DAMPs), plants alter their root growth and development by displaying a reduction in the root length and the formation of root hairs and lateral roots. The exogenous application of a MAMP peptide, flg22, was shown to affect root growth by suppressing meristem activity. In addition to MAMPs, the DAMP peptide PEP1 suppresses root growth while also promoting root hair formation. However, the question of whether and how these elicitor peptides affect the development of the vascular system in the root has not been explored. The cellular receptors of PEP1, PEPR1 and PEPR2 are highly expressed in the root vascular system, while the receptors of flg22 (FLS2) and elf18 (EFR) are not. Consistent with the expression patterns of PEP1 receptors, we found that exogenously applied PEP1 has a strong impact on the division of stele cells, leading to a reduction of these cells. We also observed the alteration in the number and organization of cells that differentiate into xylem vessels. These PEP1-mediated developmental changes appear to be linked to the blockage of symplastic connections triggered by PEP1. PEP1 dramatically disrupts the symplastic movement of free green fluorescence protein (GFP) from phloem sieve elements to neighboring cells in the root meristem, leading to the deposition of a high level of callose between cells. Taken together, our first survey of PEP1-mediated vascular tissue development provides new insights into the PEP1 function as a regulator of cellular reprogramming in the Arabidopsis root vascular system.

• International Journal of Oral Biology
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• v.39 no.4
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• pp.169-176
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• 2014

A positional scanning synthetic peptide combinatorial library (PS-SCL) was screened in order to identify antimicrobial peptides against the cariogenic oral bacteria, Streptococcus mutans. Activity against Streptococcus gordonii and Aggregatibacter actinomycetemcomitans was also examined. The library was comprised of six sub-libraries with the format $O_{(1-6)}XXXXX-NH_2$, where O represents one of 19 amino acids (excluding cysteine) and X represents equimolar mixture of these. Each sub-library was tested for antimicrobial activity against S. mutans and evaluated for antimicrobial activity against S. gordonii and A. actinomycetemcomitans. The effect of peptides was observed using transmission electron microscopy (TEM). Two semi-mixture peptides, RXXXXN-$NH_2$ (pep-1) and WXXXXN-$NH_2$ (pep-2), and one positioned peptide, RRRWRN-$NH_2$ (pep-3), were identified. Pep-1 and pep-2 showed significant antimicrobial activity against Gram positive bacteria (S. mutans and S. gordonii), but not against Gram negative bacteria (A. actinomycetemcomitans). However, pep-3 showed very low antimicrobial activity against all three bacteria. Pep-3 did not form an amphiphilic ${\alpha}$-helix, which is a required structure for most antimicrobial peptides. Pep-1 and pep-2 were able to disrupt the membrane of S. mutans. Small libraries of biochemically-constrained peptides can be used to generate antimicrobial peptides against S. mutans and other oral microbes. Peptides derived from such libraries may be candidate antimicrobial agents for the treatment of oral microorganisms.

• Journal of Periodontal and Implant Science
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• v.47 no.3
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• pp.174-181
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• 2017

Purpose: Epitope spreading is a phenomenon in which distinct subdominant epitopes become major targets of the immune response. Heat shock protein (HSP) 60 from Porphyromonas gingivalis (PgHSP60) and peptide 19 from PgHSP60 (Pep19) are immunodominant epitopes in autoimmune disease patients, including those with periodontitis. It remains unclear whether Pep19 is a dominant epitope in subjects without periodontitis or autoimmune disease. The purpose of this study was to determine the epitope spreading pattern and verify Pep19 as an immunodominant epitope in healthy teenagers using dot immunoblot analysis. The patterns of epitope spreading in age-matched patients with type 1 diabetes mellitus (type 1 DM) and healthy 20- to 29-year old subjects were compared with those of healthy teenagers. Methods: Peptide from PgHSP60, Mycobacterium tuberculosis HSP60 (MtHSP60), and Chlamydia pneumoniae HSP60 (CpHSP60) was synthesized for comparative recognition by sera from healthy subjects and patients with autoimmune disease (type 1 DM). Dot immunoblot analysis against a panel of peptides of PgHSP60 and human HSP60 (HuHSP60) was performed to identify epitope spreading, and a densitometric image analysis was conducted. Results: Of the peptide from PgHSP60, MtHSP60, and CpHSP60, PgHSP60 was the predominant epitope and was most consistently recognized by the serum samples of healthy teenagers. Most sera from healthy subjects and patients with type 1 DM reacted more strongly with PgHSP60 and Pep19 than the other peptides. The relative intensity of antibody reactivity to Pep19 was higher in the type 1 DM group than in the healthy groups. Conclusions: Pep19 is an immunodominant epitope, not only in autoimmune disease patients, but also in healthy young subjects, as evidenced by their robust immunoreactivity. This result suggests that the Pep19-specific immune response may be an initiator that triggers autoimmune diseases.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.2 no.2
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• pp.96-102
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• 2016

Apoptosis, a genetically determined process of programmed cell death, is considered a vital component of various processes including normal cell turnover, animal development, and tissue homeostasis. It has a crucial role in many medical disorders and hence the development of non-invasive imaging tool is highly demanded. Recently, we have developed a peptide-based radioactive probe (ApoPep-1) for apoptosis detection. In that work the potential of probe for apoptosis detection was verified, however in vivo stability of radiolabeled peptide was not enough to monitor apoptosis for extended period. In current study, we prepared cyclic ApoPep-1 peptides to improve the stability of origianl linear ApoPep-1 and carried out direct comparison studies in vitro and in vivo. A targeting efficacy of newly synthesized cyclic ApoPep-1 peptide for apoptosis was confirmed in acute myocardial infarct model.

• Bulletin of the Korean Chemical Society
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• v.33 no.2
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• pp.583-588
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• 2012

Functional interaction between Drosophila orphan receptor FTZ-F1 (NR5A3) and a segmentation gene product fushi tarazu (FTZ) is crucial for regulating genes related to define the identities of alternate segmental regions in the Drosophila embryo. FTZ binding to the ligand-binding domain (LBD) of FTZ-F1 is of essence in activating its transcription process. We determined solution structures of the cofactor peptide ($FTZ^{PEP}$) derived from FTZ by NMR spectroscopy. The cofactor peptide showed a nascent helical conformation in aqueous solution, however, the helicity was increased in the presence of TFE. Furthermore, $FTZ^{PEP}$ formed ${\alpha}$-helical conformation upon FTZ-F1 binding, which provides a receptor bound structure of $FTZ^{PEP}$. The solution structure of $FTZ^{PEP}$ in the presence of FTZ-F1 displays a long stretch of the ${\alpha}$-helix with a bend in the middle of helix.

• Journal of Microbiology and Biotechnology
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• v.20 no.12
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• pp.1769-1771
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• 2010

The envelope glycoprotein E2 of hepatitis C virus (HCV) binds to various cell surface receptors for viral infection. We performed biopanning against this protein and selected peptides from phage display peptide libraries. Two short peptides, pep7-1 and pep12-1, were selected and their ability to inhibit the infection process was investigated. When pep7-1 was present, the infectivity of HCV particles in cell culture was notably decreased. This decrease was demonstrated by Western blot analysis, immunofluorescence assay, and reverse transcription PCR assay. However, pep12-1 showed little inhibitory effect on HCV infection.

• BMB Reports
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• v.39 no.5
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• pp.642-647
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• 2006

Botulinum neurotoxin A (BoNT/A) has been used therapeutically to treat muscular hypercontractions and sudomotor hyperactivity and it has been reported that BoNT/A might have analgesic properties in headache. PEP-1 peptide is a known carrier peptide that delivers fulll-ength native proteins in vitro and in vivo. In this study, a BoNT/A gene were fused with PEP-1 peptide in a bacterial expression vector to produce a genetic in-frame PEP-1-BoNT/A fusion protein. The expressed and purified PEP-1-BoNT/A fusion proteins were efficiently transduced into cells in a time- and dose-dependent manner when added exogenously in a culture medium. In addition, immuno-histochemical analysis revealed that PEP-1-BoNT/A fusion protein efficiently penetrated into the epidermis as well as the dermis of the subcutaneous layer, when sprayed on mice skin. These results suggest that PEP-1-BoNT/A fusion protein provide an efficient strategy for therapeutic delivery in various human diseases related to this protein.

• Journal of Microbiology and Biotechnology
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• v.18 no.2
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• pp.328-333
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• 2008

A series of pep tides binding to the HCV NS5B polymerase was selected from phage display peptide libraries. A conserved motif of Ser-Arg-X-Arg/Leu was identified among the selected peptides, and Pep2 (Trp-Ser-Arg-Pro-Arg-Ser-Leu) was chosen for further characterization. The binding of Pep2 to HCV NS5B in vivo was shown by a yeast two-hybrid assay and by subcellular colocalization analysis using immunofluorescence confocal microscopy. The in vitro interaction was also confirmed by GST pulldown assay. The replication of the HCV 1b subgenomic replicon was efficiently inhibited by the presence of the peptide. By using a subtractive biopanning against Pep2, the binding site of the peptide was mapped at the pocket of Pro388 to Pro391 in the thumb subdomain of the polymerase. A yeast two-hybrid analysis using Pro388Ala and Pro391Ala mutants of NS5B confirmed the binding.