• Korean Journal of Plant Resources
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• v.30 no.1
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• pp.1-7
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• 2017

In this study, we produced the recombinant lunasin peptide using E. coli and P. pastoris, and evaluated biological activity of the recombinant lunasin peptide. Lunasin peptide was produced from E. coli transfected with pPGEX-lunasin expression vector and P. pastoris GS115 transfected with pPIC-lunasin expression vector. These recombinant lunasin peptides were similar to the synthetic lunasin peptide in the identification by LC-ESI-MS. In addition, the recombinant lunasin peptide from E. coli and P. pastoris was bound in the chromatin, and inhibited histone acetylation and the activity of histone acetyltransferase. These findings suggest that the production of the lunasin peptide using E. coli and P. pastoris will be useful for industrial utilization of lunasin peptide.

• Parasites, Hosts and Diseases
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• v.47 no.1
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• pp.31-36
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• 2009

Cockroaches have been recognized as a major cause of asthma. Bla g 4 is one of the most important German cockroach allergens. The aim of this study is to investigate IgE reactivity to the recombinant Bla g 4 (rBla g 4) in the sera of allergic patients and identify linear IgE binding epitope. For protein expression, full-length Bla g 4 (EF202172) was divided into 5 overlapping peptide fragments (E1: aa 1-100, E2: aa 34-77, E3: aa 74-117, E4: aa 114-156, and E5: aa 153-182). The full-length and 5 peptide fragments of Bla g 4 was generated by PCR and over-expressed in E. coli BL21 (DE3). The IgE binding reactivities of the full-length and peptide fragments were measured by ELISA using 32 serum samples of cockroach allergy. The sera of 8 patients (25%) reacted with rBla g 4. Four sera (100%) showed IgE-binding reactivity to full-length and peptide fragment 4, and 2 sera (50%) reacted with peptide fragment 2. One (20%) serum reacted with peptide fragment 3. The results of ELISA using overlapping recombinant fragments indicated that the epitope region was located at amino acid sequences 34-73 and 78-113, and major IgE epitope of Bla g 4 was located at amino acid sequences 118-152 of C-terminal. B-cell epitope analysis of German cockroach allergen Bla g 4 could contribute to the strategic development of more specific and potentially efficacious immunotherapy.

• IMMUNE NETWORK
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• v.1 no.1
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• pp.77-86
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• 2001

Background: Hepatitis C virus(HCV), a family of Flaviviridae, has a host cell-derived envelope containing a positive-stranded RNA genome, and has been known as the maj or etiological agent for chronic hepatitis, hepatic cirrhosis, and hepatocellular carcinoma. There remains a need to dissect a molecular mechanism of pathogenesis for the development of therapeutic and effective preventive measure for HCV. Identification of cellular receptor is of central importance not only to understand the viral pathogenesis, but also to exploit strategies for prevention of HCV. This study was aimed at identifying peptide mimotopes inhibiting the binding of E2 protein of HCV to MOLT-4 cell. Methods: In this study, phage peptide library displaying a random peptides consisting of 7 or 12 random peptides was employed in order to pan against E2 protein. Free HCV particles were separated from the immune complex forms by immunoprecipitation using anti-human IgG antibody, and used for HCV-capture ELISA. To identify the peptides inhibiting E2-binding to MOLT-4 cells, E2 protein was subj ect to bind to MOLT-4 cells under the competition with phage peptides. Results: Several phage peptides were selected for their specific binding to E2 protein, which showed the conserved sequence of SHFWRAP from 3 different peptide sequences. They were also able to recognize the HCV particles in the sera of HCV patients captured by monoclonal antibody against E2 protein. Two of them, showing peptide sequence of HLGPWMSHWFQR and WAPPLERSSLFY respectively, were revealed to inhibit the binding of E2 protein to MOLT-4 cell efficiently in dose dependent mode. However, few membrane-associated receptor candidates were seen using Fasta3 programe for homology search with these peptides. Conclusion: Phage peptides containing HLGPWMSHWFQR and WAPPLERSSLFY respectively, showed the inhibition of E2-binding to MOLT-4 cells. However, they did not reveal any homologues to cellular receptors from GenBank database. In further study, cellular receptor could be identified through the screening of cDNA library from MOLT-4 or hepatocytes using antibodies against these peptide mimotopes.

• Journal of Microbiology and Biotechnology
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• v.9 no.3
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• pp.303-310
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• 1999

A cost-effective mass production method for a strong antimicrobial peptide, buforin II, which was isolated from the stomach of Bufo bufo gargarizans, has been developed. This method is based on the neutralization of the positive charge of buforin II by fusion with a cysteine-rich acidic peptide (CAP) to avoid any lethal effect on the host. The neutralized fusion peptide was multimerized and expressed in Escherichia coli as tandem repeats to increase the production yield. Multimers of the CAP-buforin II fusion peptide were successfully expressed at high levels in E. coli as inclusion bodies. More than 100mg of pure buforin II was obtained per 11 of E. coli culture after cleaving the multimeric polypeptide with CNBr. The buforin II obtained from the recombinant E. coli had antimicrobial activity identical to that of natural buforin II. The proposed expression system can provide a cost-effective mass production method for both antimicrobial peptides and other host-lethal basic proteins.

• Annals of Laboratory Medicine
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• v.38 no.6
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• pp.530-537
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• 2018

Background: Measurement of insulin and C-peptide concentrations is important for deciding whether insulin treatment is required in diabetic patients. We aimed to investigate the analytical performance of insulin and C-peptide assays using the Lumipulse G1200 system (Fujirebio Inc., Tokyo, Japan). Methods: We examined the precision, linearity, and cross-reactivity of insulin and C-peptide using five insulin analogues and purified proinsulin. A method comparison was conducted between the Lumipulse G1200 and Roche E170 (Roche Diagnostics, Mannheim, Germany) systems in 200 diabetic patients on insulin treatment. Reference intervals for insulin and C-peptide concentrations were determined in 279 healthy individuals. Results: For insulin and C-peptide assays, within-laboratory precision (% CV) was 3.78-4.14 and 2.89-3.35%, respectively. The linearity of the insulin assay in the range of 0-2,778 pmol/L was $R^2=0.9997$, and that of the C-peptide assay in the range of 0-10 nmol/L was $R^2=0.9996$. The correlation coefficient (r) between the Roche E170 and Lumipulse G1200 results was 0.943 (P <0.001) for insulin and 0.996 (P <0.001) for C-peptide. The mean differences in insulin and C-peptide between Lumipulse G1200 and the Roche E170 were 19.4 pmol/L and 0.2 nmol/L, respectively. None of the insulin analogues or proinsulin showed significant cross-reactivity with the Lumipulse G1200. Reference intervals of insulin and C-peptide were 7.64-70.14 pmol/L and 0.17-0.85 nmol/L, respectively. Conclusions: Insulin and C-peptide tests on the Lumipulse G1200 show adequate analytical performance and are expected to be acceptable for use in clinical areas.

• The Korean Journal of Zoology
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• v.33 no.3
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• pp.303-309
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• 1990

In order to have a handle on the availability of eukarvotic peptide hormone precursors, a cDNA encoding angler fish prepro-SRIF I was manipulated so that it can be produced in large quantity from heterologous E. coli cells. Using T7 overexpression system, fusion constructs between the T7 phage coat protein Sl0 and the prepro-SRIF were made and modified as desired. From the host E. coli strain, BL21 DE3, harboring these plasmid constructs, three different SRIF related polypeptides were expressed in large amount and characterized. The results confirm the exact construction and authenticity of the overexpressed proteins from E. coli cells. The importance of this heterologous overexpression in hard to get peptide hormone precursors as well as the suitability of the target peptide hormone SRIF for this approach are discussed.

• BMB Reports
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• v.44 no.10
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• pp.669-673
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• 2011

Human methionine sulfoxide reductase B3A (hMsrB3A) is an endoplasmic reticulum (ER) reductase that catalyzes the stereospecific reduction of methionine-R-sulfoxide to methionine in proteins. In this work, we identified an antimicrobial peptide from hMsrB3A protein. The N-terminal ER-targeting signal peptide (amino acids 1-31) conferred an antimicrobial effect in Escherichia coli cells. Sequence and structural analyses showed that the overall positively charged ER signal peptide had an Argand Pro-rich region and a potential hydrophobic ${\alpha}$-helical segment that contains 4 cysteine residues. The potential ${\alpha}$-helical region was essential for the antimicrobial activity within E. coli cells. A synthetic peptide, comprised of 2-26 amino acids of the signal peptide, was effective at killing Gram-negative E. coli, Klebsiella pneumoniae, and Salmonella paratyphi, but had no bactericidal activity against Gram-positive Staphylococcus aureus.

• 한국유가공학회:학술대회논문집
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• 2007.09a
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• pp.13-20
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• 2007

Bovine lactoferricin(LFcin B) is a peptide of 25 amino acids that originated from the N terminus of bovine lactoferrin, and is characterized as having potent antimicrobial activity against bacteria, fungi, protozoa and viruses. But, direct expression of Lfcin B is lethal to Escherichia coli. For the efficient production of Lfcin B in E. coli, we developed an expression system in which the gene for cationic Lfcin B was fused to an anionic peptide gene, and successfully expressed the concatemeric fusion gene in E. coli. The purified recombinant Lfcin B was found to have antimicrobial activity, as the native Lfcin B peptide does.

• Fisheries and Aquatic Sciences
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• v.4 no.2
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• pp.84-87
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• 2001

Multimeric angiotensin-converting-enzyme-inhibitor (ACE}) containing a trypsin cleavable linker peptide between ACEI was constructed. We made synthetic DNA coding for the ACEI peptide with asymmetric and complementary cohesive ends of linker nucleotides. A tandemly repeated DNA cassette for the expression of concatameric short peptide multimers was constructed by ligating the basic units. The resultant multimeric peptide expressed as soluble and trypsin treated peptide was shown at the same retention time with chemically synthetic ACEI by HPLC. The present results showed that the technique developed for the production of the ACEI multimers with trypsin cleavable linker peptides can be generally applicable to the production of short peptide.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.20-21
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• 2003

Insulin-like growth factors (IGFs) are mitogenic peptide hormones that regulate embryonic development, postnatal growth and cellular differentiation in vertebrates IGFs are initially translated as pre-pro-peptides and then proteolytically processed to yield the mature IGFs and E-peptides. Like the C-peptide of pro-insulin, the E-peptides of pro-IGFs are generally believed to possess little or no biological activity other than their potential roles in the biosynthesis of the mature IGFs. Like human IGF-1, previous studies in our laboratory showed that the recombinant trout Ea4-peptide of pro-IGF-1 exhibited a dose-dependent mitegenic activity in cultured BALB/3T3 fibroblasts and other non-oncogenic transformed cells (Tian et al., 1999) We have also shown by in vitro and in vivo studies that Ea4-peptide possessed novel anti-tumor activities (Chen et al., 2002, Kuo and Chen, 2002; Kuo and Chen 2003). Recent results of studies conducted in chorionicallantoic membrane of developing chicken embryos revealed that Ea4-peptide of trout pro-IGF-1 also possesses a dose-dependent antiangiogenic activity. Together these results raised the question whether Ea4-peptide of trout pro-IGF-1 may affect heart and blood vessel development and hematopoiesis in fish embryos. (중략)