• International Journal of Industrial Entomology and Biomaterials
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• v.26 no.1
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• pp.31-40
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• 2013

Paralytic peptide binding proteins (PP-BP) are 30KP proteins that show similarity to ENF binding proteins. The ENF-BP act as active regulators of ENF peptides. ENF peptides are multifunctional insect cytokines. The comparison of gene expression in diapause induced and non-diapause eggs at different time intervals after oviposition showed an upregulation of PP at 18h as well as PP-BP at 12 and 18h after oviposition along with few other genes. The current study has been taken up to investigate the role of PP as well as PP-BP in diapause induction in polyvoltine silkworms and to study the multigene organization of PP-BP in the Bombyx mori genome. The tissue specific expression analysis revealed that, PP-BP is highly expressed in fat body followed by egg and brain while no expression was observed in midgut. The expression levels of PP and PP-BP in diapause and non-diapause eggs from 0h to 48h after oviposition, validated through realtime PCR revealed that PP is highly expressed at 18 and 24h while PP-BP expression is higher at 12 and 18h time intervals suggesting their possible role in diapause induction. The whole genome survey of the PP-BP paralogous sequences revealed a total of 46 B. mori PP-BP homologs that are classified into 3 categories viz., ENF-BP, Typical 30KPs and serine/threonine rich 30KPs. These paralogous sequences are distributed on chromosomes 7, 20, 22 and 24, all 30KP and S/T rich 30KP proteins are present in the same locus of chromosome 20.

• Parasites, Hosts and Diseases
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• v.46 no.4
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• pp.243-246
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• 2008

Bla g 2 is a cockroach allergen of great importance, This study was conducted to identify IgE-binding epitope(s) of Bla g 2 using the recombinant protein technique, Approximately 50% of tested sera showed IgE reactivity to Pichia-expressed Bla g 2 (PrBla g 2) and E. coli-expressed Bla g 2 (ErBla g 2), Only 5,3% of serum samples showed stronger reactivity to PrBla g 2 than ErBla g 2, indicating that serum was reactive to conformational or carbohydrate epitopes. The full-length and 5 peptide fragments of Bla g 2 were produced in E. coli. All fragments showed IgE-binding activity to the cockroach-allergy patients' sera. Specifically, peptide fragments of amino acid residue 1-75 and 146-225 appeared to be important for IgE-binding. The information about the IgE-binding epitope of Bla g 2 can aid in the diagnosis and treatment for cockroach allergies.

• Food Science and Preservation
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• v.20 no.3
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• pp.435-439
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• 2013

As byproducts of chicken slaughtering, chicken feathers are produced and mostly discarded without proper treatment, which results in serious environment pollution. Therefore, the appropriate treatment and utilization of chicken feathers are needed. In particular, chicken feathers can be used as protein sources for the preparation of protein hydrolysates, considering that chicken feathers have a large amount of proteins. In this study, chicken feather protein hydrolysates were prepared and their iron-binding peptides were isolated. Chicken feather protein was extracted from feathers of slaughtered chicken, and its hydrolysates were prepared via hydrolysis with Flavourzyme for 8 h. Then the chicken feather protein hydrolysates were ultra-filtered to obtain small peptide fractions and fractionated using Q-Sepharose and Sephadex G-15 columns to isolate their iron-binding peptides. Two major fractions were produced from each of the Q-Sepharose ion exchange chromatography and the Sephadex G-15 gel filtration chromatography. Among the fractions, the peptide fraction with a high iron-binding activity level, F12, was isolated. These results suggest that chicken feather protein hydrolysates can be used as iron supplements.

• Animal cells and systems
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• v.5 no.3
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• pp.199-203
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• 2001

Sperminogen was purified from the acid extracts of boar spermatozoa and partial peptide sequence of the 34-36 kd sperminogen was determined. Acid extracts of boar spermatozoa was gel-filtered through Sephadex G-75, and the 34-36 kd sperminogen was purified by preparative SDS-PAGE. The sperminogen bands were sliced out, and 34-36 kd sperminogen were eluted from the gel fragments and was subjected to peptide sequencing. Since the amino termini were blocked for Edman degradation method, internal amino acid sequences of the eluted 34-36 kd sperminogen were obtained from CNBr-digested peptides of sperminogen. Among several bands resolved on tricine SDS-PAGE, 14, 22 and 26 kd peptides were subjected to peptide sequencing. The ana1yzed amino acid sequences of the 26 and 22 kd peptides showed high homologies with that of the zona pellucida binding protein, Sp38, and the analyzed amino acid sequence of the 14 kd peptide showed neither sequence homology nor similarity with any known proteins.

• Journal of the Korean Magnetic Resonance Society
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• v.27 no.2
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• pp.5-9
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• 2023

t ENOD40B, a plant peptide hormone, was doubly labeled with C-13 and N-15 by recombinant production in Escherichia coli. The peptide was prepared by affinity chromatography followed by protease cleavage and reverse-phase chromatography. To elucidate the mode of action against its receptor, sucrose synthase, we proceeded to assign the backbone and side-chain resonances using a set of double and triple resonance experiments. This result will be used to determine the three-dimensional structure of the peptide at its bound state as well as to observe the chemical shift changes upon binding.

• BMB Reports
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• v.37 no.4
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• pp.460-465
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• 2004

A 16-residue polypeptide model with the sequence acetyl-YALSLAATLLKEAASL-OH was derived by rational de novo peptide design. The designed sequence consists of amino acid residues with high propensity to adopt an alpha helical conformation, and sequential order was arranged to produce an amphipathic surface. The designed sequence was chemically synthesized using a solid-phase method and the polypeptide was purified by reverse-phase liquid chromatography. Molecular mass analysis by electro-spray ionization mass spectroscopy confirmed the correct designed sequence. Structural characterization by circular dichroism spectroscopy demonstrated that the peptide adopts the expected alpha helical conformation in 50% acetonitrile solution. Liposome binding assay using Small Unilamellar Vesicle (SUV) showed a marked release of entrapped glucose by interaction between the lipid membrane and the tested peptide. The channel-forming activity of the peptide was revealed by a planar lipid bilayer experiment. An analysis of the conducting current at various applied potentials suggested that the peptide forms a cationic ion channel with an intrinsic conductance of 188 pS. These results demonstrate that a simple rational de novo design can be successfully employed to create short peptides with desired structures and functions.

• Journal of Microbiology and Biotechnology
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• v.30 no.12
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• pp.1810-1818
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• 2020

Inhibitor K562 (IK) protein was first isolated from the culture medium of K562 cells, a leukemia cell line, and is an inhibitory regulator of interferon-γ-induced major histocompatibility complex class II expression. Recently, exogenous truncated IK (tIK) protein showed potential as a therapeutic agent for inflammation-related diseases. In this study, we designed a novel putative anti-inflammatory peptide derived from tIK protein based on homology modeling of the human interleukin-10 (hIL-10) structure, and investigated whether the peptide exerted inhibitory effects against pro-inflammatory cytokines such as IL-17 and tumor necrosis factor-α (TNF-α). The peptide contains key residues involved in binding hIL-10 to the IL-10 receptor, and exerted strong inhibitory effects on IL-17 (43.8%) and TNF-α (50.7%). In addition, we used circular dichroism spectroscopy to confirm that the peptide is usually present in a random coil configuration in aqueous solution. In terms of toxicity, the peptide was found to be biologically safe. The mechanisms by which the short peptide derived from human tIK protein exerts inhibitory effects against IL-17 and TNF-α should be explored further. We also evaluated the feasibility of using this novel peptide in skincare products.

• 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.40 no.4
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• pp.532-538
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• 2007

Mouse ficolin A is a plasma protein with lectin activity, and plays a role in host defense by binding carbohydrates, especially GlcNAc, on microorganisms. The ficolin A subunit consists of an N-terminal signal peptide, a collagen-like domain, and a C-terminal fibrinogen-like domain. In this study, we show that ficolin A can be synthesized and oligomerized in a cell and secreted into culture medium. We also identify a functionally relevant signal peptide of ficolin A by using MS/MS analysis to determine the N-terminal sequence of secreted ficolin A. When the signal peptide of mouse ficolin A was fused with enhanced green fluorescent protein (EGFP), EGFP was released into HEK 293 cell medium, suggesting that the signal peptide can efficiently direct ficolin A secretion. Moreover, our results suggest that the signal peptide of ficolin A has potential application for the production of useful secretory proteins.

• Biomedical Science Letters
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• v.7 no.3
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• pp.103-110
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• 2001

$\alpha$-Fetoprotein(AFP) is a good marker for the detection of several diseases such as hepatocellular carcinoma, gonadal germ cell tumor, gastric tumor, and Down's syndrome. In this study, we developed ELISA, using synthetic peptides corresponding to the epitopes of AFP. Five kinds of peptides were synthesized from AFP to produce antibodies in rats that recognize AFP in human plasma as well as amniotic fluid and do not cross-react with serum albumin. All five kinds of antibodies showed good reactivities with their peptide-keyhole limpet hemocyanin conjugates. Anti-synthetic peptide 1 (R-N-E-Y-G-I-A-S-I-L, 4-13) antibody, in particular, reacted well with AEP as well as synthetic peptide 1-KLH but not with human serum albumin. The binding affinity(Kd) was 2.7$\times$10$^{-9}$M for peptide 1 and 6.8$\times$10$^{-8}$M for AEP. The range for measurement of AFP was 10~1,000 ng/ml. The within-assay and between-assay coefficients of variance(CV) were 4.83% and 10.97%, respectively. In a sample of 31 sera and 33 amniotic fluids, there was a good correlation between AFP values determined in this assay and those in a commercial kit. These results indicate that the antibodies against synthetic peptides corresponding to the epitopes of AFP are highly specific to APP and synthetic peptide-based ELISA would be useful for the measurement of human AFP.