• Journal of Animal Science and Technology
• /
• 제63권2호
• /
• pp.417-425
• /
• 2021

The use of edible insects to replace meat protein is important to ensure future global food security. However, processed foods using edible insects require development to enhance consumer perception. Here, we examined the physicochemical characteristics and rheological properties of emulsions prepared from different edible insect larvae. Three edible insect species (Tenebrio molitor, Allomyrina dichotoma and Protaetia brevitarsis seulensis) were used to prepare larval emulsions that were formulated with 65% of insect larvae, 20% of pork back fat, and 15% ice. The A. dichotoma emulsion had the highest pH and lightness, redness, and yellowness values, while the T. molitor emulsion had the lowest pH and lightness, redness, and yellowness values. The T. molitor emulsion had the highest hardness, gumminess, chewiness, and apparent viscosity values but the lowest springiness and cohesiveness values. According to the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis, T. molitor had the thickest bands, followed by P. brevitarsis seulensis. The differential scanning calorimetry distributions for the T. molitor and A. dichotoma emulsions showed one peak, while that of the P. brevitarsis seulensis emulsion had two peaks. The collective results suggest that T. molitor was the most suitable candidate (of the three tested species) for use as a meat replacement in terms of its physicochemical and rheological properties. It is important that such properties of insect-based emulsions are maintained using various technologies.

• BMB Reports
• /
• 제36권2호
• /
• pp.185-189
• /
• 2003

Chitinase (EC 3.2.1.14) was isolated from the culture filtrate of Streptomyces sp. M-20 and purified by ammonium sulfate precipitation, DEAE-cellulose ion-exchange chromatography, and Sephadex G-100 gel filtration. No exochitinase activity was found in the culture filtrate. The molecular mass of the purified chitinase was 20 kDa, estimated by a sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and was confirmed by activity staining with Calcofluor White M2R. Chitinase was optimally active at pH of 5.0 and at $30^{\circ}C$. The enzyme was stable from pH 4 to 8, and up to $40^{\circ}C$. Among the metals and inhibitors that were tested, the $Hg^+$, $Hg^{2+}$, and p-chloromercuribenzoic acid completely inhibited the enzyme activity. The chitinase activity was high on colloidal chitin, chitotriose, and chitooligosaccharide. The purified chitinase showed antifungal activity against Botrytis cinerea, and lysozyme activity against the cell wall of Botrytis cinerea.

• Parasites, Hosts and Diseases
• /
• 제42권2호
• /
• pp.81-84
• /
• 2004

The 150 kDa protein of cyst fluid (CF) of Taenia solium metacestodes was purified by ammonium sulfate fractionation and Superose 6 HR gel filtration chromatography. The purified protein consisted of three subunits (15, 10 and 7 kDa proteins), which were analyzed with the use of a 7.5-15％ gradient sodium dodecyl sulfate polyacrylamide gel electrophoresis (SOS-PAGE). Immunofluorescence study was carried out by using immunize specific polyclonal antibody. Positive reactions were noticed at bladder walls, calcareous corpuscles, granules of cyst fluid and some host tissue surrounding the bladder wall of the metacestodes. These results suggest that the 150 kDa protein was secreted into host tissues, inducing immune responses in the host, and it may play important roles in the cellular physiology of the parasites.

• 한국수산과학회지
• /
• 제28권6호
• /
• pp.728-735
• /
• 1995

The peptidyl prolyl cis-trans isomerase(PPlase, EC 5.2.2.8) from Bacillus stearothermophilus SIC1 was extracted from the cells treated with by lysozyme. PPlase was purified from the cell extracts by heat treatment, ammonium sulfate precipitation, ion exchange chromatography and finally gel filtration (FPLC). The purity of purified the enzyme after Superose 12 column chromatography was examined by sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE). The molecular weight of the purified PPlase was estimated as 18,000 by SDS-PAGE. The 39 amino acid residues from the N-terminus were determined by the protein sequencer. The enzyme showed the optimum pH at 8.0 and was stable at the range of pH 7.0 to 8.0. The enzyme was considerably stable after heat treatment at $60^{\circ}C$ for 30 minutes, and the enzyme was quite stable up to $65^{\circ}C$. The presence of the PPlase in the refolding solution accelerated the isomerization rate of the assay peptide.

• BMB Reports
• /
• 제37권4호
• /
• pp.387-393
• /
• 2004

The L-asparaginase (E. C. 3. 5. 1. 1) enzyme was purified to homogeneity from Pseudomonas aeruginosa 50071 cells that were grown on solid-state fermentation. Different purification steps (including ammonium sulfate fractionation followed by separation on Sephadex G-100 gel filtration and CM-Sephadex C50) were applied to the crude culture filtrate to obtain a pure enzyme preparation. The enzyme was purified 106-fold and showed a final specific activity of 1900 IU/mg with a 43% yield. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of the purified enzyme revealed it was one peptide chain with $M_r$ of 160 kDa. A Lineweaver-Burk analysis showed a $K_m$ value of 0.147 mM and $V_{max}$ of 35.7 IU. The enzyme showed maximum activity at pH 9 when incubated at $37^{\circ}C$ for 30 min. The amino acid composition of the purified enzyme was also determined.

• Journal of Microbiology and Biotechnology
• /
• 제16권1호
• /
• pp.25-31
• /
• 2006

Changes of CP4 5-enolpyruvylshikimate-3-phosphate synthase (CP4 EPSPS) in the glyphosate-tolerant Roundup Ready soybean were examined using purified CP4 EPSPS produced in cloned Escherichia coli as a control. CP4 EPSPS in genetically modified soybean was detected by twodimensional gel electrophoresis (2-DE) and identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and electrospray ionization tandem mass spectrometry (ESI-MS/MS) with databases. CP4 EPSPS in soybean products was resolved on 2-DE by first isoelectric focusing (IEF) based on its characteristic pI of 5.1, followed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) based on its molecular mass of 47.5 kDa. We quantified various percentages of soybean CP4 EPSPS. The quantitative analysis was performed using a 2D software program on artificial gels with spots varying in Gaussian volumes. These results suggested that 2-DE image analysis could be used for quantitative detection of GM soybean, unlike Western blotting.

• 한국식품영양과학회지
• /
• 제18권3호
• /
• pp.279-286
• /
• 1989

Alkaline protease 생성능이 강한 Aspergillus fumigatus을 토양에서 분리동정하고, 효소생산조건을 구명한 결과 $30^{\circ}C$에서 3일간 배양하였을 때 최고활성을 나타냈으며 생산된 조효소를 황산암모늄염석, Sephadex G-25, G-150 gel filteration과 DEAE-Cellulose컬럼 chromatography로 정제하여 수율 6.4%, 정제정도 86.13배의 효소를 얻었고 polyacrylamide gel 전기영동에 의해 단일밴드인 것을 확인하였다. 정제효소의 분자량은 63000정도 였으며, 17종의 아미노산으로 구성되어 있고, 그 중 glycine과 glutamic acid가 가장 많고 methionine과 cystine이 가장 적었다.

• 미생물학회지
• /
• 제25권3호
• /
• pp.180-183
• /
• 1987

Type II제한효소 Stu I을 순수정제하고 그 효소적 특성을 연구하였다. 100g(we weight)의 Streptomyces tubercidicus(ATCC 25502)로부터 얻은 crude extranct를 ammonium sulfate fractionation한 후, DEAE-Sephadex(A-50), QAE-Sephadex(A-50) 그리고 Heparin-agarose의 순서로 column chromatography를 수행하여 1,2mg의 비특이성 nuclease가 없는 Stu I 제한효소를 얻었다. 이 시료에 포함되어 있는 다른 오염 단백질은 Sephadex G-100 column으로 gel filtration 하여 제거함으로써, 순수한 Stu I 단백질을 얻을 수 있었다. 정제된 Stu I 제한효소는 10% SDS-polyacrylamide gel electrophoresis 결과 한 개의 band로 나타났으며, 그 분자량은 34,000 $\pm$ 1,000 dalton이었다. 이 효소는 $Mg^{2+}$이온 존재하에 중성의 pH(7.0-8.0)에서 최대의 활성을 나타내었다. NaCl은 이 효소의 활성에는 필요하지 않았다.

• Journal of Microbiology and Biotechnology
• /
• 제18권4호
• /
• pp.670-675
• /
• 2008

A laccase was isolated from the culture filtrate of the basidiomycete Fomitella fraxinea. The enzyme was purified to electrophoretical homogeneity using ammonium sulfate precipitation, anion-exchange chromatography, and gel-filtration chromatography. The enzyme was identified as a monomeric protein with a molecular mass of 47 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and gel-filtration chromatography, and had an isoelectric point of 3.8. The N-terminal amino acid sequence for the enzyme was ATXSNXKTLAAD, which had a very low similarity to the sequences previously reported for laccases from other basidiomycetes. The optimum pH and temperature for 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) were 3.0 and $70^{\circ}C$, respectively. The enzyme also showed a much higher level of specific activity for ABTS and 2,6-dimethoxyphenol (DMP), where the $K_m$ values of the enzyme for ABTS and 2,6-DMP were 270 and $426{\mu}M$, respectively, and the $V_{max}$ values were 876 and $433.3{\mu}M/min$, respectively. The laccase activity was completely inhibited by L-cysteine, dithiothreitol (DTT), and sodium azide, significantly inhibited by $Ni^+,\;Mn^{2+}$, and $Ba^{2+}$, and slightly stimulated by $K^+$ and $Ca^{2+}$.

• Applied Biological Chemistry
• /
• 제29권1호
• /
• pp.57-61
• /
• 1986

네품종의 보리(올보리, 영산보리, 사천 6호, 수원 228호)로 부터 Osborne의 방법과 이것을 변형한 전보의 방법으로 단백질을 분획하여 albumin, globulin, hordein 및 glutelin 획분을 얻어 이들 각획분들을 SDS-PAGE로 분석한 결과 품종간 polypeptide 조성 차이를 관찰할 수 있었으며 특히 hordein과 hordein-I을 pH 3에서 PAGE를 수행 하였을 때 각 품종사이의 pattern에 명확한 차이를 볼 수 있었다. 한편, hordein-I의 아미노산조성은 glutamic acid와 proline 함량이 높았으나 품종간의 아미노산조성차이는 거의 볼 수 없었다.