• Korean Journal of Microbiology
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• v.45 no.4
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• pp.332-338
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• 2009

A xylan-decomposing bacterium, HY-20, was isolated from the gut of a honeybee, Apis mellifera, and identified as Bacillus sp. The extracellular GH11 xylanase (XylP) gene (687-bp) of strain HY-20 encoded a protein of 228 amino acids with a deduced molecular mass of 25,522 Da and a calculated pI of 9.33. The primary structure of XylP was 97% identical to that of B. pumilus xylanase (GenBank accession no.: AY526092) that has not been characterized yet. The recombinant His-tagged enzyme (rXylP) overexpressed in Escherichia coli BL21 harboring pET-28a(+)/xylP was purified to electrophoretic homogeneity by cation exchange and gel permeation chromatographies. The purified enzyme exhibited the highest catalytic activity toward birchwood xylan at pH 6.5 and $50^{\circ}C$ and retained approximately 50% of its original activity when pre-incubated at $55^{\circ}C$ for 15 min. The recombinant enzyme was completely inactivated by $Hg^{2+}$ (1 mM) and N-bromosuccinimide (5 mM), while its activity was slightly stimulated by approximately 10% in the presence of $Mn^{2+}$ (1 mM), $Fe^{2+}$ (1 mM), and sodium azide (5 mM). rXylP was able to efficiently degrade various polymeric xylose-based substrates but PNP-sugar derivatives and glucose-based polymers were not susceptible to the enzyme.

• Microbiology and Biotechnology Letters
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• v.33 no.4
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• pp.281-287
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• 2005

The endoinulinase gene (inu, 2.733 kb, EC 3.2.1.7) from Paenibacillus polymyxa was subcloned into an Escherichia coli-yeast shuttle vector with GALl promoter for the expression in Saccharomyces cerevisiae. The constructed plasmid, pYGENIU27 (8.6 kb) was introduced into S. cerevisiae SEY2102 cell and then the yeast transformant was selected on the synthetic defined media lacking uracil and on the inulin-containing media. The recombinant endoinulinase was predominantly localized in the periplasmic space of the yeast cell. The total activity of the endoinulinase reached 1.81 unit/ml by cultivation of yeast transformant on YPDG medium. The optimized conditions determined for the inulooligosaccharides (IOSs) production from inulin were as follows; pH, 8.0; reaction temperature, $45^{\circ}C$; inulin source, Jerusalem artichoke. Enzyme activity was stably maintained up to the pH of 10.0. Under the optimized condition and with endoinulinase of 36 unit/g-inulin, IOSs started to be produced after 10 min of enzymatic reaction. By the reaction with inulin, IOSs consisting of inulobiose (F2), inulotriose (F3), and inulotetraose (F4) were produced and F3 was the major product. Consequently, these data would be used as a fundamental parameters for the production of functional sweetener IOSs from inulin by recombinant yeast endoinulinase.

• Journal of Periodontal and Implant Science
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• v.42 no.4
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• pp.119-126
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• 2012

Purpose: The aim of this study was to determine whether biphasic calcium phosphate (BCP) bone substitute with two different concentrations of Escherichia coli-expressed recombinant human bone morphogenetic protein 2 (ErhBMP-2) enhances new bone formation in a standardized rabbit sinus model and to evaluate the concentration-dependent effect of ErhBMP-2. Methods: Standardized, 6-mm diameter defects were made bilaterally on the maxillary sinus of 20 male New Zealand white rabbits. Following removal of the circular bony windows and reflection of the sinus membrane, BCP bone substitute without coating (control group) was applied into one defect and BCP bone substitute coated with ErhBMP-2 (experimental group) was applied into the other defect for each rabbit. The experimental group was divided into 2 subgroups according to the concentration of ErhBMP-2 (0.05 and 0.5 mg/mL). The animals were allowed to heal for either 4 or 8 weeks and sections of the augmented sinus and surrounding bone were analyzed by microcomputed tomography and histologically. Results: Histologic analysis revealed signs of new bone formation in both the control and experimental groups with a statistically significant increase in bone formation in experimental group 1 (0.05 mg/mL ErhBMP-2 coating) after a 4-week healing period. However, no statistically significant difference was found between experimental group 1 and experimental group 2 (0.5 mg/mL ErhBMP-2 coating) in osteoinductive potential (P<0.05). Conclusions: ErhBMP-2 administered using a BCP matrix significantly enhanced osteoinductive potential in a standardized rabbit sinus model. A concentration-dependent response was not found in the present study.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2010.05a
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• pp.17-17
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• 2010

Ethylene, known as a stress hormone regulate wide developmental processes including germination, root hair initiation, root and shoot primordial formation and elongation, leaf and flower senescence and abscission, fruit ripening. The acceleration of ethylene biosynthesis in plant associated with environmental and biological stresses. 1-Aminocycloprophane-1-carboxlyate deaminase(ACCD) is an enzyme that cleaves ACC into and ammonia, a precursor of the plant hormone ethylene. Plant growth-promoting rhizobacteria (PGPR) having ACCD can decrease endogenous ACC level of tissue, resulting in reduced production of ethylene in plants. ACC deaminse was a key enzyme for protect stressed plants from injurious effects of ethylene. ACCD gene was encoded from Pseudomonas flourescens, PGPR and was cloned in Escherichia coli. We expressed the recombinant ACCD(rACCD) containing 357 amino acids with molecular weight 39 kDa that revealed by SDS-PAGE and western blot. The rACCD was purified by Ni-NTA purification system. The active form of rACCD having enzyme activity converted ACC to a-ketobutyrate. The optimal pH for ACC deaminase activity was pH 8.5, but no activity below pH 7.0 and a less severe tapering activity at base condition resulting in loss of activity at over pH 11. The optimal temperature of the enzyme was $30^{\circ}$ and a slightly less severe tapering activity at 15 - 30$^{\circ}$, but no activity over $35^{\circ}$. P. flourescens ACC deaminase has a highly conserved residue that plays in allowing substrate accessibility to the active sites. The enzymatic properties of this rACCD will provide an important reference for analysis of newly isolated ACCD and identification of newly isolated PGPR containing ACCD.

• Parasites, Hosts and Diseases
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• v.52 no.1
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• pp.93-97
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• 2014

Subolesin (4D8), the ortholog of insect akirins, is a highly conserved protective antigen and thus has the potential for development of a broad-spectrum vaccine against ticks and mosquitoes. To date, no protective antigens have been characterized nor tested as candidate vaccines against Dermacentor silvarum bites and transmission of associated pathogens. In this study, we cloned the open reading frame (ORF) of D. silvarum 4D8 cDNA (Ds4D8), which consisted of 498 bp encoding 165 amino acid residues. The results of sequence alignments and phylogenetic analysis demonstrated that D. silvarum 4D8 (Ds4D8) is highly conserved showing more than 81% identity of amino acid sequences with those of other hard ticks. Additionally, Ds4D8 containing restriction sites was ligated into the pET-32(a+) expression vector and the recombinant plasmid was transformed into Escherichia coli rosetta. The recombinant Ds4D8 (rDs4D8) was induced by isopropyl ${\beta}$-D-thiogalactopyranoside (IPTG) and purified using Ni affinity chromatography. The SDS-PAGE results showed that the molecular weight of rDs4D8 was 40 kDa, which was consistent with the expected molecular mass considering 22 kDa histidine-tagged thioredoxin (TRX) protein from the expression vector. Western blot results showed that rabbit anti-D. silvarum serum recognized the expressed rDs4D8, suggesting an immune response against rDs4D8. These results provided the basis for developing a candidate vaccine against D. silvarum ticks and transmission of associated pathogens.

• Journal of Life Science
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• v.21 no.11
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• pp.1652-1657
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• 2011

The production of blood cells is regulated by more than 20 different growth factors, called hematopoitic growth factors. These factors have been produced in prokaryotic and mammalian systems for their clinical use. Glranulocyte-Colony Stimulating Factor (G-CSF) is an important therapeutic factor for cancer patients as well as patients with congenital conditions. These patients do not have enough neutrophils and have a high risk of infection. Two groups of recombinant G-CSF have been used to specially treat cancer patients after chemotherapy because chemotherapy induces neutropenia, a major side effect of chemotherapy drugs. Here, structural and biological characteristics of G-CSF are presented. In addition, the relationship between chemotherapy and neutropenia, which is a severe reduction of neutrophils in the blood, and clinical application of G-CSF is discussed. Recombinant G-CSFs are grouped in two forms. Non-glycosylated G-CSF, filgrastim, is produced in Escherichia coli and glycosylated G-CSF, lenograstim, is produced in Chinese hamster ovary cells. Differences in structure and biological activity are compared and challenges for biosimilar production are also highlighted.

• Korean Journal of Microbiology
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• v.41 no.1
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• pp.87-92
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• 2005

Pronase, a protease produced for commercial purpose by Streptomyces griseus, was composed of serine protease, alkaline protease, aminopeptidase and carboxypeptidase complex, and it has been widely used as anti-inflammatory drugs for human therapy. In this study, we developed a new integration vector, pHJ101 derived from pSET152, containing strong promoter, ermE, to overexpress a certain protease gene. Specific PCR primers for cloning of sprA (a gene for S. griseus protease A) and sprB (a gene for S. griseus protease B) genes were designed from the basis of nucleotide sequence in databases and amplified by PCR. Plasmid pHJ201 and pHJ202 were constructed by inserting of amplified each gene in a vector pHJ101. S. griseus HA and S. griseus HB were respectively obtained by conjugal process of a parent strain, S. griseus IFO 13350 with the recombinant Escherichia coli harboring plasmid pHJ201 or pHJ202. When protease activity was measured in flask cultivation, produced protease levels of S. griseus HA and S. griseus HB increased about 5.3 times and 5 times, respectively, more than that of parent strain. And, the constructed integrating plasmid pHJ101 was applicable for overexpression of a certain gene in Streptomyces sp.

• Journal of Microbiology and Biotechnology
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• v.30 no.11
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• pp.1720-1728
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• 2020

We have previously characterized AprESJ4, the major fibrinolytic enzyme from Bacillus subtilis SJ4 (Yao et al., 2019). During that study, we observed a 68 kDa protein with fibrinolytic activity. In this study, we cloned the gene (vprSJ4) encoding the 68 kDa protein, a mature Vpr and minor protease secreted by Bacillus species. vprSJ4 encodes a preproenzyme consisting of 810 amino acids (aa) including signal sequence (28 aa) and prosequence (132 aa). The mature enzyme (650 aa) has a predicted molecular weight of 68,467.35. Unlike Vprs from other B. subtilis strains, VprSJ4 has 4 additional amino acids (DEFA) at the C-terminus. vprSJ4 was overexpressed in Escherichia coli. PreproVprSJ4 was localized in inclusion bodies, and subjected to in vitro renaturation and purification by an affinity column. SDS-PAGE and western blot showed that autoprocessing of preproVprSJ4 occurred and 68 kDa and smaller proteins were produced. The optimum pH and temperature of the recombinant VprSJ4 were pH 7.0 and 40℃, respectively. Kinetic parameters of recombinant VprSJ4 were measured by using an artificial substrate, N-succinyl-ala-ala-pro-phe-p-nitroanilide. Coexpression of vprSJ4 and aprESJ4 using pHY300PLK increased the fibrinolytic activity a further 117% when compared with aprESJ4 single expression using the same vector in B. subtilis WB600.

• Journal of Life Science
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• v.21 no.1
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• pp.68-73
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• 2011

$\beta$-1,3-glucanase from Pyrococcus furiosus was applied for the saccharification of laminarin, which is a major oligo-saccharide component of brown algae, and the reaction mixture produced from laminarin was utilized as a substrate for alcohol fermentation using yeast. To prepare the recombinant $\beta$-1,3-glucanase, a $\beta$-1,3-glucanase gene was overexpressed in Escherichia coli and purified. Laminarin was degraded to an oligo- and mono-saccharide, such as glucose, after reaction with the purified recombinant $\beta$-1,3-glucanase, and the products after enzymatic treatment were confirmed by TLC and HPLC analysis. Decomposed laminarin after enzyme reaction was only added to the medium as a C-source for yeast alcohol production reaction. 0.3% alcohol production was detected from the cultured broth by gas chromatography after 48 hr of incubation. Further evaluation for optimal conditions of saccharification and alcohol fermentation can be suggested, as well as the possibility of using this enzymatic method to produce ethanol using laminarin.

• Korean Journal of Microbiology
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• v.47 no.4
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• pp.348-355
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• 2011

Staphylococcus aureus is a major human pathogen that is associated with various types of local and systemic infection. Staphylococcal protin A (SPA), a highly expressed surface component of S. aureus, may have a role in virulence such as activating inflammation and interfering with immune clearance. We examined the effect of recombinant SPA on inflammatory response in human HaCaT keratinocytes. The recombinant SPA protein was prepared using the pET-28a Vector System in Escherichia coli. The expression of pro-inflammatory related adhesion molecules and cytokines in HaCaT cells incubated for 6, 12, and 24 h with SPA (2 ${\mu}g$/ml) was analyzed by comparative RT-PCR or ELISA. The expression of E-selectin, ICAM-1, MCP-1, IL-6 and IL-8 was significantly increased in HaCaT from 6 to 24 h after treatment with SPA. SPA showed the effect on the adhesion-promoting ability of U937 monocytes to HaCaT cells. Our data demonstrate that SPA stimulates inflammatory response of HaCaT cells, implicating an important factor for exacerbation of skin inflammation of immunologic disease.