• Journal of Pharmaceutical Investigation
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• 제40권4호
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• pp.251-254
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• 2010

The formation of acylated peptide impurities in poly(lactide-co-glycolide) (PLGA) formulations is one of the major challenges to the development of successful sustained-release product. Octreotide, synthetic analogue of somatostatin, has been identified to be acylated in PLGA microsphere formulations. The purpose of this study was to investigate the pH effect on the formation of acylated octreotides by PLGA. In the incubation with PLGA in 0.1 M phosphate buffer at pH 7.4, approximately 98% of octreotide adsorbed to PLGA through 14 days and 66.3% of acylated octreotides were produced after 42 days, whereas the interaction of octreotide with PLGA was significantly inhibited in the incubation at pH 4, in which the acylated octreotides were observed to be 9.2% after 42 days. In the interaction study at pH 4.1-7.4, the production of acylated octreotides was demonstrated to be dependent on environmental pH. Below pH 5.0, the acylation of octreotide was significantly inhibited. This study indicates that the pH is the major factor for the formation of acylated octreotide in PLGA formulations.

• International Journal of Industrial Entomology and Biomaterials
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• 제43권2호
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• pp.94-98
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• 2021

Reactive oxygen species (ROS) induce a variety of cellular responses, such as proliferation, differentiation, senescence, and apoptosis. Intestinal epithelial cells are continuously exposed to ROS, and excessive generation of ROS severely damages cells via oxidative stress. Pro-inflammatory cytokines may lead to intestinal inflammation and damage by inducing excessive ROS generation. In this study, we showed that papiliocin, an antimicrobial peptide, significantly inhibited ROS production, without affecting cell viability. Moreover, TNF-α and IL-6 expression was decreased in the intestinal epithelial cells. The activity of papiliocin may significantly contribute to preserving the integrity of the intestinal mucosa against oxidative damage and inflammation-related disorders.

• 한국해양바이오학회지
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• 제16권1호
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• pp.55-62
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• 2024

Various antimicrobial peptides (AMPs) from microalgae have shown antibacterial, antiviral, antifungal, anticancer, and antioxidant effects, and play crucial roles in medical applications, aquaculture-related disease management, and the food industry. Magainin 2 (MAG2), an AMP, exhibits high antibacterial and antitumor activity, necessitating an efficient recombinant expression system for low-cost, large-scale production. To enhance MAG2 secretion efficiency in Chlorella, we constructed the SS:MAG2:His vector using the known Chlamydomonas reinhardtii CA1 signal sequence (SS) and obtained a stable transformant via an Agrobacterium-mediated transformation method and RT-qPCR. ELISA results revealed that the MAG2 content secreted into the medium by the SS:MAG2:His transformants increased proportionally with mRNA expression. These findings offer a strategy for high MAG2 secretion in the Chlorella vulgaris platform, potentially minimizing downstream processing costs.

• Journal of Microbiology and Biotechnology
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• 제23권5호
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• pp.689-698
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• 2013

The production and characterization of an active recombinant N-acetylgalactosamine-6-sulfate sulfatase (GALNS) in Escherichia coli BL21(DE3) has been previously reported. In this study, the effect of the signal peptide (SP), inducer concentration, process scale, and operational mode (batch and semi-continuous) on GALNS production were evaluated. When native SP was presented, higher enzyme activity levels were observed in both soluble and inclusion bodies fractions, and its removal had a significant impact on enzyme activation. At shake scale, the optimal IPTG concentrations were 0.5 and 1.5 mM for the strains with and without SP, respectively, whereas at bench scale, the highest enzyme activities were observed with 1.5 mM IPTG for both strains. Noteworthy, enzyme activity in the culture media was only detected when SP was presented and the culture was carried out under semi-continuous mode. We showed for the first time that the mechanism that in prokaryotes recognizes the SP to mediate sulfatase activation can also recognize a eukaryotic SP, favoring the activation of the enzyme, and could also favor the secretion of the recombinant protein. These results offer significant information for scaling-up the production of human sulfatases in E. coli.

• 한국식품영양과학회지
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• 제34권6호
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• pp.904-909
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• 2005

일본 청국장에서 분리된 Bacillus firmus NA-1를 이용하여 비지의 수분함량, 생대두미세분말첨가 및 발효시간에 따른 비지 발효물의 혈전용해효소, 점질물, 펩타이드생산 및 풍미 개선 효과를 알아보았다. 비살균 D-비지는 30시간 이상부터 청국장 발효가 진행되는 반면, 살균 D-비지는 18시간부터 고초균 발효에 의하여 pH가 증가하였으며 혈전분해효소, 펩타이드 함량이 비살균 D-비지보다 높은 값을 보였다 P-비지의 경우는 18시간 발효시에 가장 높은 pH, tyrisone 함량과 혈전용해효소활성을 나타냈다. 또한 P-비지를 건조하여 초기수분함량을 $60\%$로 낮추었을 때 발효비지물의 펩타이드 함량과 혈전용해분해효소활성이 증가하였다. p-비지에 전지활성 생대두미세분말을 $10\%$수준으로 첨가함으로써 혈전분해효소 및 펩타이드 함량이 증가되는 효과를 보였으며, 점질물의 생성에 따른 점조도 값의 증가를 나타내었다. 특히, 콩미세분말을 $20\%$ 수준으로 첨가하여 발효시킨 비지는 고유한 청국장의 풍미를 나타내었으며, 건조시킨 발효비지물의 조단백질함량은 $27.3\%$를 나타내었다. 따라서 비지의 고초균 발효시에 전지활성 생대두미세분말의 첨가는 비지의 초기수분함량을 낮추면서, 고초균 발효의 촉진을 통한 콩 펩타이드 및 혈전용해효소의 증가, 점질물 생산, 풍미 개선을 비롯하여 발효비지의 단백질 보강이 가능하였다.

• 한국미생물·생명공학회지
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• 제23권5호
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• pp.602-608
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• 1995

The aim of the present research program was to construct an optimum fermentation system and to characterize the properties of cathepsin B inhibitor from Streptomyces chromofuscus SMF28. Glucose and casitone were proved to be good carbon source and nitrogen source, respectively. The production of inhibitor was high at lower concentration than 10 mM of inorganic phosphate. The optimum temperature and pH for the production of inhibitor were 30$\circ$C and pH 7, respectively. The production of inhibitor was related to mycelial growth and was affected by medium composition. The inhibitor in culture filtrate of S. chromofuscus SMF28 was purified by butanol extraction, silica gel chromatography, Amberlite IRC-50 (H$^{+}$ form) chromatography, preparative TLC, and preparative HPLC. From amino acid analysis and UV, IR, $^{1}$H-NMR spectroscopic analysis, the inhibitor was identified as a peptide containing valine and phenylalanine derivative.

• International Journal of Industrial Entomology and Biomaterials
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• 제31권2호
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• pp.85-89
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• 2015

This peptide has antibacterial activity against several Gram-positive and Gram-negative bacteria. Bombyx mori cecropinB1(BmCecB1) is antimicrobial peptides from Bombyx mori and belongs to cecropin family. Antimicrobial peptides are important components of the innate immune systems in all living organism. To produce the BmCecB1 antimicrobial peptide, we constructed transgenic silkworm that expressed BmCecB1 gene under the control BmA3 promoter using piggyBac vector. The use of the 3xP3-driven EGFP cDNA as a marker allowed us to rapidly distinguish transgenic silkworm. Mixtures of the donor vector and helper vector were micro-injected into 600 eggs of bivoltin silkworms, Baegokjam. In total, 49 larvae (G0) were hatched and allowed to develop into moths. The resulting G1 generation consisted of 22 broods, and we selected 2 broods containing at least 1 EGFP-positive embryo. The rate of successful transgenesis for the G1 broods was 9%. We identified 9 EGFP-positive G1 moths and these were backcrossed with wild-type moths. With the aim of identifying a BmCecB1 as antimicrobial peptide, we investigated the Radical diffusion Assay (RDA) and then demonstrated that BmCecB1 possesses high antibacterial activities against Gram-negative bacteria.

• Asian-Australasian Journal of Animal Sciences
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• 제21권12호
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• pp.1800-1806
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• 2008

Cytokines play a central role in the mucosal immune response and are involved in regulation of nutrient absorption, metabolism and animal growth. This study investigated the effect of diet manipulation with specialized protein or peptide sources on expression of cytokine (IL-1, IL-6, IL-10, and TNF-${\alpha}$) mRNA abundance in different intestinal regions and at different ages post-weaning in piglets. A total of 48 (17 days of age, $6.16{\pm}0.34kg\;BW$) weanling pigs were fed either a corn-soy/whey protein basal diet, the basal diet supplemented with spray-dried plasma protein (SDPP), or the basal diet supplemented with $Peptiva^{(R)}$, a hydrolyzed marine plant protein. A fourth treatment group was fed the SDPP diet, but the feed intake level was limited (SDPP-LF). Pigs were killed at 3 and 10 d, and intestinal cytokine mRNA was measured by real-time PCR using the relative quantification method. The SDPP-LF group exhibited an increased TNF-${\alpha}$ mRNA abundance compared with the ad libitum SDPP group (p<0.05). The TNF-${\alpha}$ and IL-10 mRNA abundance increased from the proximal to distal part of the intestine, and the mRNA abundance was greater (p<0.01) in the distal intestine as compared with the proximal and middle intestine. The cytokines IL-1-${\beta}$, IL-10 and TNF-${\alpha}$ mRNA abundance also increased from d3 to d10 postweaning (p<0.01). In summary, restricted feeding increased the TNF-${\alpha}$ mRNA abundance in the small intestine, however neither SDPP nor peptide supplementation affected cytokine mRNA expression. Abundance of mRNA for most cytokines examined in this study increased with age post-weaning, suggesting that during 10 d after weaning the mucosal immune system is still under development.

• 미생물학회지
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• 제51권2호
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• pp.177-180
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• 2015

Bordetella bronchiseptica에 의한 돼지위축성비염과 Salmonella gallinarum에 의한 가금티푸스 방지 방법을 찾기 위해서 두 세균병원체에 항균활성을 갖는 세균 균주를 축산농가의 여러 시료로부터 분리하였다. 분리균주 372개 중 TK3 균주가 두 병원체에 대해 가장 우수한 항균활성을 나타내었으며, 16S rRNA 염기서열 분석 결과 Bacillus amyloliquefaciens로 동정되었다. B. amyloliquefaciens TK3는 siderophore, rhamnolipid와 antimicrobial peptide 같은 항균물질을 분비하여 두 병원체의 생장을 저해할 수 있었다. TK3 균주는 Chrome azurol S 한천 평판에서 siderophore 생성반지름이 14일 배양 후 0.53 cm이었으며, King's B 배지에서 1.06 mmol/ml의 siderophore를 생성하였다. 또한 82.4 mg/L의 rhamnolipid를 분비하였으며, LB배지에 $30{\mu}l/ml$ 농도의 추출된 antimicrobial peptide 첨가 시 두 병원체의 생장을 완전히 저해하였다.

• The Korean Journal of Physiology and Pharmacology
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• 제15권5호
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• pp.273-277
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• 2011

Nitric oxide (NO) and atrial natriuretic peptide (ANP) may induce vascular relaxation by increasing the production of cyclic guanosine monophosphate (cGMP), an important mediator of vascular tone during sepsis. This study aimed to determine whether regulation of NO and the ANP system is altered in lipopolysaccharide (LPS)-induced kidney injury. LPS (10 $mg{\cdot}kg^{-1}$) was injected in the tail veins of male Sprague-Dawley rats; 12 hours later, the kidneys were removed. Protein expression of NO synthase (NOS) and neutral endopeptidase (NEP) was determined by semiquantitative immuno-blotting. As an index of synthesis of NO, its stable metabolites (nitrite/nitrate, NOx) were measured using colorimetric assays. mRNA expression of the ANP system was determined by real-time polymerase chain reaction. To determine the activity of guanylyl cyclase (GC), the amount of cGMP generated in response to sodium nitroprusside (SNP) and ANP was calculated. Creatinine clearance decreased and fractional excretion of sodium increased in LPS-treated rats compared with the controls. Inducible NOS protein expression increased in LPS-treated rats, while that of endothelial NOS, neuronal NOS, and NEP remained unchanged. Additionally, urinary and plasma NOx levels increased in LPS-treated rats. SNP-stimulated GC activity remained unchanged in the glomerulus and papilla in the LPS-treated rats. mRNA expression of natriuretic peptide receptor (NPR)-C decreased in LPS-treated rats, while that of ANP and NPR-A did not change. ANP-stimulated GC activity reduced in the glomerulus and papilla. In conclusion, enhancement of the NO/cGMP pathway and decrease in ANP clearance were found play a role in the pathogenesis of LPS-induced kidney injury.