• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.4
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• pp.342-348
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• 2004

Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the $60\%$ isopropanol extract of soybean(Glycine max [L.] Merr.) seed revealed two abundant proteins with molecular masses of 19 and 10 kDa. Amino acid analysis revealed that the isopropanol-extractable protein fraction was rich in cysteine. Two-dimensional gel electro-phoretic analysis indicated that the 19kDa and 10kDa proteins had pI of 4.2 and 4.0 respectively. Peptide mass fingerprints of trypsin digests of the two proteins obtained using matrix-assisted, laser desorption/ionization-time of flight (MALDI-TOF) mass spectroscopy revealed the 19kDa protein was Kunitz trypsin inhibitor and the 10kDa protein was Bowman-Birk proteinase inhibitor. When resolved under non-denaturing conditions, the isopropanol-extracted proteins inhibited trypsin and chymotrypsin activity. Results presented in this study demonstrate that isopropanol extraction of soybean seed could be used as a simple and rapid method to obtain a protein fraction enriched in Kunitz trypsin and Bowman-Birk proteinase inhibitors. Since proteinase inhibitors are rich in sulfur amino acids and are putative anticarcinogens, this rapid and inexpensive isolation procedure could facilitate efforts in nutrition and cancer research.

• Journal of Microbiology and Biotechnology
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• v.25 no.1
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• pp.127-136
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• 2015

Cupredoxin-like proteins are mainly copper-binding proteins that conserve a typical rigid Greek-key arrangement consisting of an eight-stranded β-sandwich, even though they share as little as 10-15% sequence similarity. The electron transport function of the Cupredoxins is critical for respiration and photosynthesis, and the proteins have therapeutic potential. Despite their crucial biological functions, the identification of the distant Cupredoxin homologs has been a difficult task due to their low sequence identity. In this study, the overlapped conserved residue (OCR) fingerprint for the Cupredoxin superfamily, which consists of conserved residues in three aspects (i.e., the sequence, structure, and intramolecular interaction), was used to detect the novel Cupredoxin homologs in the NCBI non-redundant protein sequence database. The OCR fingerprint could identify 54 potential Cupredoxin sequences, which were validated by scanning them against the conserved Cupredoxin motif near the Cu-binding site. This study also attempted to model the 3D structures and to predict the functions of the identified potential Cupredoxins. This study suggests that the OCR-based approach can be used efficiently to detect novel homologous proteins with low sequence identity, such as Cupredoxins.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.9
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• pp.1296-1302
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• 2004

This study was conducted to evaluate the possible application of 2 D-SDS-PAGE (2 DE)-based proteome analysis techniques to the assessment of extreme proteolysis in postmortem skeletal muscle. Eight Hanwoo longissimus muscles were incubated immediately after slaughter for 24 h at 5$^{\circ}C$, 15$^{\circ}C$ or 36$^{\circ}C$. Warner Bratzler (WB)-shear force and ultrastructural configuration were determined at 24 h, and rate of proteolysis to 24 h was determined by 1 D-SDS-PAGE (1 DE) and 2 DE. In addition, tentative protein identification was performed from peptide mass fingerprints of MALDI-ToF analysis of major protein groups on 2 DE profiles. The result showed that although ultrastructural configuration was similar between the 5$^{\circ}C$ and 36$^{\circ}C$ treatments, meat at 5$^{\circ}C$ had higher WBshear force (approximately 5 kg greater). A higher rate of protein degradation at 36$^{\circ}C$ was observed based on Troponin-T degradation, 1 DE, and 2 DE analysis. This indicates that proteolysis during the early postmortem period was a significant determinant of shear force at 24 h. Little difference in proteolysis between 5$^{\circ}C$ and 15$^{\circ}C$ treatments was found based on classic 1 DE profile assessment. Meanwhile, considerable differences in the 2 DE profiles between the two treatments were revealed, with substantially higher rate of proteolysis at 15$^{\circ}C$ compared to 5$^{\circ}C$. Nuclease treatment improved 2 DE profile resolution. 400 ${\mu}$g and 600 ${\mu}$g of sample loading appeared to be appropriate for 24 cm pH 3-10 and pH 5-7 IPG strips, respectively. Protein detection and quantification of the 5$^{\circ}C$, 15$^{\circ}C$ and 36$^{\circ}C$ 2 DE profiles revealed 78, 163 and 232 protein spots respectively that were differentially modified in terms of their electrophoretic properties between approximately pI 5.3-7.7 with the molecular weight range of approximately 71-12 kDa. The current results demonstrated that 2 DE was a superior tool to 1 DE for characterising proteolysis in postmortem skeletal muscle.

• Journal of Microbiology and Biotechnology
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• v.16 no.6
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• pp.855-862
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• 2006

Hexavalent chromium ($Cr^{6+}$) is a highly harmful pollutant, which can be detoxified and precipitated through reduction to $Cr^{3+}$. Bacillus megaterium TKW3 previously isolated from chromium-contaminated marine sediments was capable of reducing $Cr^{6+}$ in concomitance with metalloids ($Se^{4+}$, $Se^{6+}$, and $As^{5+}$). Notwithstanding approximately 50% inhibition, it was the first report of simultaneous bacterial reduction of $Cr^{6+}$ and $Se^{4+}$ (to elemental Se). No significant difference was observed among electron donors (glucose, maltose, and mannitol) on $Cr^{6+}$ reduction by B. megaterium TKW3. The reduction was constitutive and determined to be non-plasmid mediated. Peptide mass fingerprints (PMF) revealed a novel aerobic membrane-associated reductase with $Cr^{6+}$-induced expression and specific reductive activity (in nmol $Cr^{6+}$/mg protein/min) of 0.220 as compared with 0.087 of the soluble protein fraction. Respiratory inhibitor $NaN_3$ did not interfere with the reductase activity. Transmission electron microscopy with energy dispersive X-ray (TEM-EDX) analysis confirmed the aggregation of reduced chromium along the intracellular membrane region. Future identification of the N-terminal amino acid sequence of this reductase will facilitate purification and understanding of its enzymatic action.

• Microbiology and Biotechnology Letters
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• v.48 no.2
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• pp.138-147
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• 2020

Various microorganisms play important roles in food fermentation, food spoilage, and agriculture. In this study, the biotype of 54 yeast and bacterial strains having high potential for utilization in food and agriculture, including Candida spp., Lactobacillus spp., and Acetobacter spp., were characterized by matrix-assisted laser desorption/ionization time-of flight mass spectrometry (MALDI-TOF MS). This characterization using a fast and robust method provides much-needed information on the selected microorganisms and will facilitate effective usage of these strains in various applications. Importantly, the unique protein profile of each microbial species obtained from this study was used to create a database of fingerprints from these species. The database was validated using microbial strains of the same species by comparing the mass spectra with the created database through pattern matching. The created reference database provides crucial information and is useful for further utilization of a large number of valuable microorganisms relevant to food and agriculture.

• Journal of Microbiology and Biotechnology
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• v.20 no.8
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• pp.1210-1214
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• 2010

Many bacteria are involved in the fermentation of doenjang, and Bacillus species are known to perform significant roles. Although SDS-PAGE has been frequently used to classify and identify bacteria in various samples, the microbial diversity in doenjang has not yet been investigated. This study aims to determine the identity and distribution of dominant Bacillus species in doenjang using SDS-PAGE profiles of whole-cell proteins and 16S rRNA gene sequencing. Reference Bacillus strains yielded differential SDS-PAGE banding patterns that could be considered to be highly specific fingerprints. Grouping of bacterial strains isolated from doenjang samples by whole-cell protein patterns was confirmed by analysis of their 16S rRNA gene sequences. B. subtilis was found to be the most dominant strain in most of the samples, whereas B. licheniformis and B. amyloliquefaciens were less frequently found but were also detected in several samples. The results obtained in this study show that a combined identification method using SDS-PAGE profiles of whole-cell proteins and subsequent 16S rRNA gene sequence analysis could successfully identify Bacillus species isolated from doenjang.

• Food Science of Animal Resources
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• v.43 no.6
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• pp.1055-1066
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• 2023

The cultured meat industry is continuously evolving due to the collective efforts of cultured meat companies and academics worldwide. Though still technologically limited, recent reports of regulatory approvals for cultured meat companies have initiated the standards-based approach towards cultured meat production. Incidents of deception in the meat industry call for fool-proof authentication methods to ensure consumer safety, product quality, and traceability. The cultured meat industry is not exempt from the threats of food fraud. Meat authentication techniques based on DNA, protein, and metabolite fingerprints of animal meat species needs to be evaluated for their applicability to cultured meat. Technique-based categorization of cultured meat products could ease the identification of appropriate authentication methods. The combination of methods with high sensitivity and specificity is key to increasing the accuracy and precision of meat authentication. The identification of markers (both physical and biochemical) to differentiate conventional meat from cultured meat needs to be established to ensure overall product traceability. The current review briefly discusses some areas in the cultured meat industry that are vulnerable to food fraud. Specifically, it targets the current meat and meat product authentication tests to emphasize the need for ensuring the traceability of cultured meat.

• Journal of The Korean Society of Grassland and Forage Science
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• v.31 no.2
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• pp.99-106
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• 2011

In order to investigate rice stem proteome in response to heat stress, rice plants were subjected to heat treatment at 42$^{\circ}C$ and total soluble proteins were extracted from stem tissues, and were fractionated with 15% PEG (poly ethylene glycol) and separated by two-dimensional polyacrylamide gel electrophoresis (2-DE). After staining of 2-DE gels, 46 of differentially expressed proteins were extracted, digested by trypsin, and subjected to matrix assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) analysis. Proteins were identified through database search by using peptide mass fingerprints. Among them, 10 proteins were successfully identified. Seven proteins were up- and 3 proteins were down-regulated, respectively. These proteins are involved in energy and metabolism, redox homeostasis, and mitochondrial small heat shock proteins. The identification of some novel proteins in the heat stress response provides new insights that can lead to a better understanding of the molecular basis of heat-sensitivity in plants, and also useful to molecular breeding of thermotolerant forage crops.