• Fisheries and Aquatic Sciences
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• 제13권4호
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• pp.343-349
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• 2010

The effects of osmotic stress on the non-specific immune response of Nile tilapia, Oreochromis niloticus, were investigated. Osmoregulatory mechanism of tilapia has been studied, but less information is available about innate immune response of O. niloticus faced with hyperosmolality. Acute osmotic stress was elicited by transferring tilapia from freshwater (FW) to 24 psu seawater (SW). Non-specific immune parameters including lysozyme activities of plasma and head kidney (HK), alternative complement pathway (ACP) activity in plasma, phagocytic capacities of spleen and HK immune cells, and respiratory burst activity of immune cells in both HK and spleen were analyzed. Lysozyme activities were increased at 1 h and 30 h after transfer to SW, but decreased at 10 h after SW transfer. Conversely, ACP activity increased 10 h after SW transfer. Phagocytic capacity increased slightly at 1 h and 5 h after SW transfer, and respiratory burst activity showed an increase in superoxide release at 10 h after SW transfer. Taken together, these results indicate that the exposure of tilapia to hyperosmotic conditions has immunostimulatory effects on cellular and humoral immune reactions.

• Applied Biological Chemistry
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• 제37권6호
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• pp.456-462
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• 1994

라이소자임-덱스트란 hybrids는 상대 습도 80%와 $60^{\circ}C$에서 16일간 유지시켜 만들었다. 라이소자임-덱스트란 hybrids의 유화성은 라이소자임보다 약 14배 정도, 시판유화제보다는 약3배 정도 높았다. 그 hybrids의 효소 활성도는 기질로 Micrococcus lysodeiticus 세포벽을 사용한 결과 라이소자임의 약 83% 정도였다. 그 hybrids의 뛰어난 유화성은 pH 3에서도 유지되었고 pH 10에서는 더욱 개선되었다. $100^{\circ}C$로 가열 처리함으로써 유화성은 크게 향상되었다. 또한 라이소자임-덱스트란 hybrids 이 그람음성세균에 대하여 항균효과를 나타냈다. 이 결과들은 라이소자임-덱스트란 hybrids가 식품에서 보존료와 유화제로 사용될 수 있다고 사료된다.

• Fisheries and Aquatic Sciences
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• 제13권4호
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• pp.300-307
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• 2010

This study examined the effects of the dietary inclusion of various concentrations of red ginseng byproduct (RB) and a mixture containing red ginseng byproduct, garlic extract, yeast and filler (CR) on the growth, body composition, serum chemistry, and lysozyme activity of juvenile olive flounder (Paralichthys olivaceus). Juvenile fish (n= 630) weighing 5.0 g were randomly distributed into 21 180 L flow-through tanks (30 fish/tank). Seven experimental diets were prepared in triplicate: a control diet without additive, and diets containing 0.5, 1 and 2% concentrations of RB (RB-0.5, RB-1, RB-2) and CR (CR-0.5, CR-1, CR-2) at the expense of wheat flour. After an 8-week feeding trial, serum chemistry and lysozyme activity of fish were measured. Mean weight gain was significantly higher in fish fed the control diet than in fish fed the RB and CR diets. The dietary inclusion of RB and CR reduced feed utilization. Mean serum glucose and triglyceride (TG) levels were higher in fish fed the control diet than in fish fed the other diets. Mean glutamate pyruvate transaminase (GPT) levels of fish fed the control and RB-2 diets were higher than those of fish fed the RB-0.5, RB-1, CR-1, and CR-2 diets. Mean lysozyme activity levels of fish fed the RB-0.5 and RB-1 diets were higher than those of fish fed the control and CR diets. The results of this study indicate that red ginseng byproduct may be utilized as an immunostimulant rather than as a growth promoter for juvenile olive flounder. Dietary inclusion of 0.5% red ginseng byproduct effectively improved serum glucose, GPT, TG, and lysozyme activity of the fish in this study.

• Asian-Australasian Journal of Animal Sciences
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• 제23권6호
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• pp.742-749
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• 2010

We investigated the antioxidant efficacy of quercetin (0% Diet 1, 0.25% Diet 2, and 0.5% Diet 3) pretreatment for 30 and 60 days in response to cadmium (Cd) toxicity in the olive flounder, and measured the plasma lysozyme activity to understand the immune effects of quercetin. The lysozyme activity with Diets 2 and 3 was higher than with Diet 1. Based on this result, to examine the immune ability and antioxidant role of quercetin, we exposed olive flounder fed quercetin to Cd and then measured the expression and activity of antioxidant enzymes (superoxide dismutase (SOD) and catalase (CAT)) and lipid peroxidation (LPO). With Diets 2 and 3, the expression and activity of antioxidant enzymes and the $H_2O_2$ concentration were lower than with Diet 1. In addition, the LPO levels were lower than with Diet 1, which protected the cell membrane. Therefore, quercetin removed the reactive oxygen species (ROS) produced by Cd, indicating that quercetin has antioxidant ability. In addition to its antioxidant ability, quercetin has immune effects.

• 한국어병학회지
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• 제22권3호
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• pp.367-374
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• 2009

오매 추출물 첨가 사료의 투여가 양식 뱀장어의 비특이적 면역 반응에 미치는 효과를 조사하였다. 그 결과, 뱀장어의 혈청 내 lysozyme의 활성을 증가시키는 것으로 나타났고, 점액 내 lysozyme 및 혈청의 살균능에 있어서는 차이를 나타내지 않았다. 혈청 내 lysozyme의 활성은 추출물 첨가 사료 투여 후 2주째에 증가하기 시작하여 5주째에 가장 높은 것으로 나타났다. 어류 병원성 세균인 Edwardsiella tarda와 Aeromonas hydrophila 균에 대한 저항성 실험에 서 오매 추출물 첨가 사료을 투여한 실험구가 대조구에 비해 세균에 대한 저항성이 높게 나타났다. 또한 오매 추출물 첨가 사료를 투여한 실험구에서 대조구에 비해 성장이 좋게 나타났다.

• 미생물학회지
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• 제25권4호
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• pp.309-317
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• 1987

정상 상태의 연두금 파리 (Lucilia illustris) 제 3령충의 체액 (normal-haemolymph)으로 부터 그람양성 세균에 대하여 항균력이 있는 lysozymec (or lysozyme-like substance)을 확인하였으며 체벽을 손상시킨 체액 (injured-haemolymph)의 경우 그 항균력이 증가되었다. 특히 비병원성 세균인 Escherichia coli K-12로 면역하여 얻은 체액 (immune-haemolymph)의 경우 injured-haemolymph보다 그람양성 세율에 대하여 더 높은 항균력을 보였을 뿐만 아니라 그람음성 세균인 E. coli에 대하여 도 항균력을 나타내었다. Immune-haemolymph로 부터 유효 분획을 얻고 이에 대한 성상을 분석하기 위하여 Sephacryl S-300 및 CM-Sepharose CL-6B로 분리시킨 결과 상기 항균울질은 엽기성 만백질로서 산성하에서 내열성의 성질을 나타냈다.

• Asian-Australasian Journal of Animal Sciences
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• 제28권12호
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• pp.1774-1783
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• 2015

Milk lysozyme is the ubiquitous enzyme in milk of mammals. In this study, the cDNA sequence of a new chicken-type (c-type) milk lysozyme gene (YML), was cloned from yak mammary gland tissue. A 444 bp open reading frames, which encodes 148 amino acids (16.54 kDa) with a signal peptide of 18 amino acids, was sequenced. Further analysis indicated that the nucleic acid and amino acid sequences identities between yak and cow milk lysozyme were 89.04% and 80.41%, respectively. Recombinant yak milk lysozyme (rYML) was produced by Escherichia coli BL21 and Pichia pastoris X33. The highest lysozyme activity was detected for heterologous protein rYML5 (M = 1,864.24 U/mg, SD = 25.75) which was expressed in P. pastoris with expression vector $pPICZ{\alpha}A$ and it clearly inhibited growth of Staphylococcus aureus. Result of the YML gene expression using quantitative polymerase chain reaction showed that the YML gene was up-regulated to maximum at 30 day postpartum, that is, comparatively high YML can be found in initial milk production. The phylogenetic tree indicated that the amino acid sequence was similar to cow kidney lysozyme, which implied that the YML may have diverged from a different ancestor gene such as cow mammary glands. In our study, we suggest that YML be a new c-type lysozyme expressed in yak mammary glands that plays a role as host immunity.

• Applied Biological Chemistry
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• 제37권1호
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• pp.49-55
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• 1994

벼잎의 산성용액 추출물로부터 ion exchange chromatography chitin affinity chromatography chromatofocusing gel slicing 등의 방법으로 단백질 RCG-2를 순수분리하였다. 본 단백질은 chitin과 laminarin을 가수분해하므로 chitinase와 ${\beta}-1,3-glucanase$ 활성을 함께 보유하고 있는 것으로 나타났으며, 이외에도 M. lysodeiktikus cell wall을 가수분해하는 lysozyme 활성도 보유하는 것으로 판명되었다. 분자량이 29.77 kd인 본 효소의 chitinase 활성은 pH 4.0에서, ${\beta}-1,3-glucanase$ 활성은 pH 7.0에서 최대로 나타났고, 최적온도는 두 효소 활성 모두 $40^{\circ}C$ 이었다. chitin에 대한 $K_M$ 값은 7.86 mM, $V_{max}$는 $0.025\;{\mu}M/min$, laminarin $({\beta}-1,3-glucan)$에 대한 것은 각각 5.95 mM, $0.16{\mu}\;M/min.$ 이었으며, 정제된 효소는 chitin을 chitooligosaccharide로 분해하는 것으로 나타나서 endochitinase로 판명되었다.

• Journal of Oral Medicine and Pain
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• 제43권1호
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• pp.1-7
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• 2018

Purpose: The purpose of the study was to investigate the influences of hyaluronic acid on the candidacidal activities of lysozyme, the peroxidase system, and the glucose oxidase-mediated peroxidase (GO-PO) system at different concentrations of antimicrobial enzymes. Methods: Hyaluronic acid was used at a final concentration of 0.5 mg/mL. Hen egg-white lysozyme (HEWL) was used at concentrations ranging from 10 to $100{\mu}g/mL$. The peroxidase system included bovine lactoperoxidase (bLPO), potassium thiocyanate (KSCN, 1 mM), and hydrogen peroxide ($100{\mu}M$). The GO-PO system included bLPO, KSCN (1 mM), glucose oxidase (10 units/mL), and glucose ($30{\mu}g/mL$). The final concentration of bLPO in the peroxidase and GO-PO systems ranged from 12.5 to $100{\mu}g/mL$. Candida albicans strains ATCC 10231, 11006, and 18804 were utilized. Candidacidal activities of antimicrobials and the influence of hyaluronic acid on their candidacidal activities were determined based on colony forming units. Results: Candidacidal activities of the peroxidase and GO-PO systems increased with increasing concentrations of bLPO. This tendency was the same in the presence or absence of hyaluronic acid. Candidacidal activity of HEWL was not significantly concentration-dependent. Candidacidal activities of the GO-PO system were higher than those of the corresponding peroxidase system. Candidacidal activity was inhibited in the presence of hyaluronic acid in the following order: HEWL, the peroxidase system, and the GO-PO system. Conclusions: Hyaluronic acid inhibited the candidacidal activities of HEWL, the peroxidase system, and the GO-PO system. The GO-PO system exhibited better candidacidal activity than HEWL and the peroxidase system both in the presence and absence of hyaluronic acid.

• 한국어병학회지
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• 제25권1호
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• pp.1-10
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• 2012

여러 항산화물질이 어류의 비특이적 면역능을 증강시키는 것이 알려져 있다. 본 연구에서는 glutathione의 생합성 전구체인 항산화물질 N-acetylcysteine(NAC)이 8종의 어류에서 비특이적 면역지표를 증가시키는 지를 검토하였다. NAC를 10 mg/kg의 용량으로 메기, 미꾸라지, 잉어, 붕어, 뱀장어, 가물치, 틸라피아 및 숭어에 복강내로 투여하고, 48시간 후 두신백혈구 세포의 화학발광반응 및 혈청 lysozyme 활성을 측정하였다. 붕어와 미꾸라지를 제외한 6종의 어류에서 화학발광 반응이, 틸라피아를 제외한 모든 어류에서 lysozyme 활성이 각각 증가하였다. 이 결과는 NAC가 다양한 어종에서 비특이적 면역증을 증가시키며, 이 현상은 어류양식에서의 실용화도 고려해 볼 가치가 있음을 의미한다.