• Journal of Animal Science and Technology
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• 제62권5호
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• pp.741-752
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• 2020

Herein, the in vitro protein digestibility of lyophilized Protaetia brevitarsis larvae flour with and without defatting using 70% ethanol was compared with beef loin. Proximate analysis showed that the defatted larvae contained the highest protein content (p < 0.05). The viable counts of total aerobic bacteria, Escherichia coli, and coliform bacteria decreased significantly after defatting the larval samples with 70% ethanol (p < 0.05). Measurement of α-amino group content and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed higher amounts of low molecular weight proteins in the larvae compared to beef loin (p < 0.05). After in vitro digestion, the degree of protein hydrolysis of the digesta was higher for both larvae samples compared to beef loin (p < 0.05). No change was observed in the in vitro larval protein digestibility after defatting. These results highlight the excellent protein digestibility of P. brevitarsis larvae with high protein content. Defatting insect flour with 70% ethanol could enhance microbial safety while maintaining excellent protein digestibility.

• Bulletin of the Korean Chemical Society
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• 제31권2호
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• pp.275-280
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• 2010

Actinobacillus actinomycetemcomitans is a gram-negative, nonmotile coccobacillus bacterium that is associated with several human diseases, including endocarditis, meningitis, osteomyelitis, subcutaneous abscesses and periodontal diseases. A full-length Omp1-like protein gene from A. actinomycetemcomitans was cloned into a pQE30 vector and overexpressed in Escherichia coli BL21(DE3) cells. The protein revealed sequence homologies to Seventeen kilodalton proteins (Skp) from Pasteurella multocida and E. coli that have been characterized as periplasmic chaperones. This soluble Omp1-like protein was successfully purified to homogeneity for further folding and functional studies. The purity, identity, and conformation of the protein were determined using sodium dodecyl sulfate polyacrylamide gel electrophoresis, matrix-assisted laser desorption ionization mass spectrometry, circular dichroism, fluorescence spectroscopic, and differential scanning calorimetric studies. We showed that the protein formed an oligomer larger than a tetramer. We found, further, that it is comprised of mostly $\alpha$-helices and boasts high thermal stability.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.139.2-140
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• 2003

Ornithogalum showing mosaic symptoms were collected from the isolated field of National Plant Quarantine Service in Sengrimmyon of Kyungnam province. Electron microscopic examination of negatively strained preparation was filamentous particle of 740nm in lenght. Indirect-ELISA determined that the virus was serologically related to potyvirus. A single major protein band of Mr 30,000 was observed after sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Indicator plant test showed masaic, necrotic local lesion and sunken areas in leaves of Nicotiana clevelandii and Tetragonia expansa, while the others of indicator plants did not infect. An enzyme-aided purification protocal was used, which eliminated a highly viscous mucilage from extracts of the Omithogalum. Total RNA extracted from infected Omithogalum leaves were amplified of 411b.p fragment in reverse transcription (RT)-PCR when primers specilic for the coat protein gene. An isolate of Omithogalum mosaic virus (OrMV) of the genus Potyvirus was identified as the casual agent of the disease on the basis of electron microscopic, biological and serological reaction.

• 한국축산식품학회지
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• 제38권5호
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• pp.1101-1108
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• 2018

The aim of this study was to investigate the effects of dry-aging (DA) and the cooking process on the myofibril protein functionalities and in vitro digestibility of proteins in beef loin. Six sirloins from beef were dry-aged for 28 d, and the control group (n=6) was analyzed 2 d postmortem for this study. Dimensional changes (reduction of thickness and surface shrinkage) after cooking were significantly greater in the control group than the DA group, whereas the shear force of the DA group was significantly lower than that of the control. Effect of cooking on aggregation, hydrophobicity, and in vitro digestibility were significantly higher in the DA group than in the control. After cooking, the protein in DA sirloins was more oxidized than in the control samples. According to the sodium dodecyl sulfate-polyacrylamide gel electrophoresis result, the low molecular weight bands (below 17 kDa) increased in the DA group, finding that the protein characteristics of dry-aged beef was affected by cooking.

• 한국축산식품학회지
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• 제38권5호
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• pp.950-958
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• 2018

The physicochemical characteristics and oxidative stability of wet-aged and dry-aged pork cuts were investigated at different aging periods (1, 7, 14 and 21 d). Samples were assigned into four groups in terms of shoulder blade-wet aging (SW), shoulder blade-dry aging (SD), belly-wet aging (BW), and belly-dry aging (BD). SD showed significantly higher pH at 21 d of aging than the other samples. Wet-aged cuts had significantly higher released water (RW) %, lightness ($L^*$) and shear force compared to the dry-aged meats. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis showed greater degradation of proteins for dry-aged cuts than the wet-aged cuts. At the end of aging, wet-aged cuts showed significantly lower thiobarbituric acid-reactive substances (TBARS) value than the dry-aged samples, indicating higher oxidative stability for wet-aged pork cuts. However, dry-aging led to higher degradation of proteins resulting in increased water-holding capacity (WHC) and decreased shear force value.

• 한국균학회지
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• 제32권2호
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• pp.125-129
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• 2004

섬유소분해효소(CMCase)를 산업적으로 이용하기 위한 기초자료를 제공하고자 섬유소분해능이 우수한 L. japonicus로부터 CMCase를 분리 정제하였다. L. japonicus의 배양액으로부터 4단계를 거쳐 분자량이 42 kDa인 CMCase를 분리 정제하였다. 이 효소는 pH 6.0에서 최적의 활성을 보여주는 acidic CMCase로서 $30^{\circ}C$에서 최대 활성을 나타냈다. EDTA에 의해 활성이 저해되는 것으로 보아 metalloenzyme으로 추정되며, SDS에 의해 저해되는 것으로 보아 S-S기를 갖고 있는 효소로 판단된다. $Al_{2}(SO_{4})_{3}$와 $BaCl_{2}$에서는 효소 활성이 높았으나 그 이외의 금속염에서는 효소 활성이 낮았다.

• International Journal of Industrial Entomology and Biomaterials
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• 제25권2호
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• pp.181-185
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• 2012

Chymotrypsin serine protease is one of the main digestive proteases in the midgut of and is involved in various essential processes. In a previous study, a gene encoding a chymotrypsin-like protease, Hi-SP1, was cloned from the larvae of Hermetia illucens and characterized. In this study, we produced the recombinant chymotrypsin-like protease Hi-SP1 in Escherichia coli cells. The molecular weight of the recombinant Hi-SP1 was estimated to be approximately 26 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western-blotting. Chymotrypsin activity was detected when AAPF was used as the substrate. Examination of the effects of temperature and pH revealed that the proteolytic activity of recombinant Hi-SP1 decreased markedly at temperatures above $30^{\circ}C$, and the optimum pH was found to be 10.0.

• 한국미생물·생명공학회지
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• 제17권5호
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• pp.494-498
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• 1989

AIDS 환자의 치명적인 2차 감염을 유발하는 Cryptosporidium parvum 의 Infective stage 인 sporozoites의 단일군 항체를 분리하였다. Oocysts를 효소처리하여 sporozoites를 excystation시킨 후 Isopycnic percoll gradients를 이용하여 sporozoites를 순수분리한 후 단일군 항체 생산을 위한 항원으로 사용하였다. 두 달된 BALB/c 쥐를 immunize한 후 splenocytes와 P3-X63-Ag8 myeloma cells를 융합시킨 후 hybridoma 기술을 이용해 Kor1(IgGl), Ea2(Ig2a) 두 clones을 분리하였으며 정제된 sporozoites를 SDS-PAGE로 분리한 후 Western blot을 이용하여 단일군 항체 Kor1과 Ea2는 20,000 daltons 크기의 항원을 인식하였다. Immunofluorescent assay에서 단일군 항체가 sporozoites 표면에 반응하는 것으로 보아 20-kDa 단백질 항원은 sporozoites 표면에 위치하는 항원으로 밝혀졌으며 C. parvum에 감염되었을 때 항체생성에 관여하는 중요 항원 중 하나일 것으로 추정되었다.

• Journal of Microbiology and Biotechnology
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• 제4권1호
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• pp.41-48
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• 1994

The xylanase from alkali-tolerant Bacillus sp. YA-14 was purified to homogeneity by CM-cellulose, Sephadex G-50, and hydroxyapatite column chromatographies. The molecular weight of the purified enzyme was estimated to be 20, 000 Da by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The purified enzyme slightly hydrolyzed carboxymethyl cellulose and Avicel, but did not hydrolyze soluble starch, dextran, pullulan, and ${\rho}-nitrophenyl-{\beta}$-D-xylopyranoside. The maximum degree of hydrolysis by enzyme for birchwood xylan and oat spelts xylan were 47 and 40%, respectively. The Michaelis constants for birchwood xylan and oat spelts xylan were calculated to be 3.03 mg/ml and 5.0 mg/ml, respectively. The activity of the xylanase was inhibited reversibly by $HgCl_2$, and showed competitive inhibition by N-bromosuccinimide, which probably indicates the involvement of tryptophan residue in the active center of the enzyme. The Xylanase was identified to be xylose-producing endo-type xylanase and did not show the enzymatic activities which cleave the branch point of the xylan structure.

• Journal of Microbiology and Biotechnology
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• 제25권6호
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• pp.887-892
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• 2015

Uricase is an important microbial enzyme that can be used in the clinical treatment of gout, hyperuricemia, and tumor lysis syndrome. A total of 127 clinical isolates of Pseudomonas aeruginosa were tested for uricase production. A Pseudomonas strain named Ps43 showed the highest level of native uricase enzyme expression. The open reading frame of the uricase enzyme was amplified from Ps43 and cloned into the expression vector pRSET-B. Uricase was expressed using E. coli BL21 (DE3). The ORF was sequenced and assigned GenBank Accession No. KJ718888. The nucleotide sequence analysis was identical to the coding sequence of uricase gene puuDof P. aeruginosa PAO1. We report the successful expression of P. aeruginosa uricase in Escherichia coli. E. coli showed an induced protein with a molecular mass of about 58 kDa that was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting. We also established efficient protein purification using the Ni-Sepharose column with activity of the purified enzyme of 2.16 IU and a 2-fold increase in the specific activity of the pure enzyme compared with the crude enzyme.