• Korean Journal of Food Science and Technology
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• v.24 no.3
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• pp.284-288
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• 1992

This study was undertaken to investigate the effect of pH and phytate level on the solubility of the protein due to binding between phytate and low-phytate rapeseed protein isolate by means of SDS-polyacrylamide gel electrophoresis. Results showed that the number of protein bands decreased by the increasing amount of phytate added to the soluble extract at pH 2.0 and 5.0 whereas there was no change at pH 11.5. Among 18 bands of rapeseed proteins at pH 2.0, seven bands (105.8, 52.3, 37.3, 34.8, 26.3, 21.3, 18.4 KDa) were removed by precipitation with 100 mg phytate addition and six bands (78.8, 46.5, 19.4, 16.8, 11.7, 8.5 KDa) further disappeared by 150 mg phytate addition. Among 15 bands at pH 5.0, only four bands disappeared by phytate addition. It is suggested that the functionality of rapeseed protein isolate can be improved by lowering the phytate content.

• Korean Journal of Food Science and Technology
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• v.10 no.4
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• pp.415-422
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• 1978

Some minor Korean beans including red bean, mung bean and kidney bean were subjected to proximate analysis, fractionation by the solubility method and polyacrylamide gel disc electrophoresis of proteins to obtain the following results. 1) Proximate composition of the beans showed that fat content was less than 1%, carbohydrate was about 60% and protein content was in the range of $20{\sim}25%$. 2) Total globulin content of the proteins was $46{\sim}59%$, a little lower than in soybean, in the order of mung bean> kidney bean> red bean. Albumin content was comparable in kidney bean, and lower in red bean and mung bean as compared with that in soybean. Glutelin content was relatively higher, being in the range of $10{\sim}19%$ and in the order of red bean> mung bean> kidney bean. 3) According to the electrophoretic pattern, total protein fractions extracted with pH 7.6 buffer from red bean, mung bean and kidney bean showed 9.12 and 11 bands, respectively, whereas those extracted with pH 4.8 buffer showed 13, 13 and 12 bands, respectively. Water extracts of red bean, mung bean and kidney bean showed 10, 8 and 9 bands, respectively, while albumin fractions showed 8, 9 and 7 bands and globulin fractions, 4 bands in all of three beans. The band having a Rm value of $0.5{\sim}0.7$ in the globulin fraction from three beans was not observed in the water extract and appears to be specific to water insoluble globulin.

• Korean Journal of Food Science and Technology
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• v.20 no.6
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• pp.883-889
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• 1988

The salted small shrimps(Acetes japonicus) were fermented for 3 months at room temperature. During the period of fermentation, the changes of shrimp protein properties were determined. The extractability of soluble protein was slightly decreased in 1 month fermentation, but thereafter increased. The contents of 10% TCA soluble fraction were gradually increased during 3 month fermentation, and the rate of 10% TCA soluble fraction/total soluble protein was also greatly increased during the period of fermentation. Sephadex G-100 gel filtration pattern was changed after 1 month fermentation, showing the disappearance of low molecular weight protein peaks, the decomposition and the delay of elution time of main shrimp protein peaks. Polyacrylamide gel disc electrophoresis patterns showed the degradation of main protein bands into lots of smaller bands after 1 month fermentation. The contents of total free amino acids were slightly decreased in 1 month fermentation and then gradually increased during the Period of fermentation. The rate of free amino acids/soluble protein was steadily increased during the period of fermentation, but the rate of free amino acids/10% TCA soluble fraction was decreased continually during the period of fermentation. The contents of most free amino acids were increased during the period of fermentation, but those of histidine and arginine were greatly decreased in 1 month fermentation. Ammonia was increased after 1 month fermentation. The pH value of salted shrimp was slowly changed during 3 months of fermentation, showing increase from 7.8 to 8.2.

• Parasites, Hosts and Diseases
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• v.26 no.2
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• pp.87-94
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• 1988

By affinity chromatography using a monoclonal antibody as ligand, Kim et at. (1986) purified a protein fraction in cystic fluid of Taenia solium metacestodes (CF) In this study, the biochemical properties of the purified protein were characterized. Discontinuous-polyacrylamide gel electrophoresis (disc-PAGE) of the protein at 4.5∼10% separating gel concentration showed its molecular weight (MW) to be 150 kilodalton (kDa) in non·denatured state, while denaturing sodium dodecyl suifate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed that it was composed of 3 different subunits with respective fnw of 15, 10 and 7 kDa. Subunit of 7 kDa was shown to be linked to other subunits by disulade bonds. Isoelectric point of the protein was pH 6.8. The protein was relatively heat-stable for immunologic analysis. These properties indicated that the protein, comprising about 70% of total content in CF, had similar biochemical characters with antigen B of Oriol et at.(1971) in hydatid cyst quid (HF).

• Korean Journal of Microbiology
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• v.32 no.3
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• pp.215-221
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• 1994

The complete nucleotide sequence of the cloned pga gene encoding the penicillin G acylase of Bacillus megaterium ATCC 14945 and its 5'- and 3'-flanking regions was determined. The sequence revealed only one large open reading frame (2,406 hp) of the penicillin G acylase (pga) gene. Upstream from ATG of the pga gene, there was a putative ribosome binding site, Shine-Dalgarno sequence. The promoter-like structure, - 10 and - 35 sequences, was also found. Following the stop codon, TAG, a structure reminiscent of the E. coli rho-independent transcription terminator was present. The amino acid sequence was deduced from the nucleotide sequence. The molecular mass of the polypeptide was 91,983 Da. There was a potential signal sequence in its amino-terminal region. A comparison of its deduced amino acid sequence with other characterized penicillin G acylases and the result of SDS-polyacrylamide gel electrophoresis of the purified enzyme showed that a precursor polypeptide of 92 kDa was processed into two dissimilar ${\alpha}$ and ${\beta}$-subunits of 25 and 61 kDa.

• Biomedical Science Letters
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• v.1 no.1
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• pp.9-18
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• 1995

Genetic polymorphisms due to variation in the number of tandem repeats of DNA sequences(VNTRs) provides a useful means for discrimination between individuals. Allele and genotype frequencies of the highly polymorphic Human Thyroid Peroxidase(TPO) gene were determined in Korean population samples by using PCR followed by polyacrylamide gel electrophoresis, a procedure called the amplified fragment length polymorphism(Amp-FLP) technique. In 123 unrelated Korean individuals 10 different alleles and 29 genotypes were observed. The TPO gene demonstrated a heterozygosity of 0.707 and the power of exclusion(POE) was 0.945. The probability of having the same DNA band within two unrelated individuals was 14.6$\times10^{-2}$. The distribution of observed genotypes conformed to Hardy-Weinberg equilibrium($x^2$=4.48, 0.05

• Korean Journal of Microbiology
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• v.40 no.2
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• pp.81-86
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• 2004

Among the annotated ORFs of Streptomyces coelicolor, SCO7697 was supposed to encode for phytase (myo-inositol hexakisphosphate phosphohydrolase). The DNA fragment containing SCO7697 was cloned by the PCR from the chromosomal DNA of S.coelicolor A3(2)M. The cloned fragment was introduced into E. coli expres-sion vector, pET28a(+), to yield two recombinant plasmids, pET28-SP and pET28-LP, which were designed to encode different length of proteins. When the pET28-SP and pET28-LP were introduced into E. coli BL21, the transformants successfully overexpressed recombinant proteins, but the molecular weights of the expressed pro-teins were appeared bigger than those of expected in SDS-polyacrylamide gel electrophoresis. The shift of cul-tural temperature from 37 to $30^{\circ}C$ made most of expressed protein be solubilized. The expressed protein, however, did not show any phytase activity. When the DNA fragment with its own promoter placed on the E. coli-Streptomyces vector, pWHM3, and introduced into S. lividans, the phytase activity was not detected either. These results suggest that even though the SCO7697 was annotated as a probable phytase with high probability (E value is $6e^{-89}$), the real product doest not have phytase activity.

• Applied Biological Chemistry
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• v.36 no.2
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• pp.105-110
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• 1993

Inulin fructotransferase from Enterobacter sp. S45 was purified with DEAE-cellulose column chromatography and fast protein liquid chromatography. The purified enzyme gave a single band on polyacrylamide gel electrophoresis. The molecular weight was estimated to be 42,800 by SDS-polyacrylamide gel electrophoresis. The optimal pH and temperature for the enzyme reaction were pH 5.5 and $55^{\circ}C$, respectively. $Mg^{2+}$ activated the enzyme activity, but $Fe^{3+}$, $Cu^{2+}$, $Hg^{2+}$ significantly inhibited. After exhaustive digestion of inulin by the enzyme, DFA III, sucrose, 1-kestose and nystose were produced. Sucrose, 1-kestose, raffinose and melezitose can't be used as substrates by the enzyme, but nystose and 1-F-fructofuranosyl nystose were hydrolysed. The Km and Vmax for inulin of the enzyme were 1.4 mM and $0.196\;{\mu}mole/min$, respectively.

• Applied Biological Chemistry
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• v.22 no.1
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• pp.1-9
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• 1979

The physical and chemical properties of ${\gamma}-conglycinin$ of soybean (Glycine max) were investigated. The soybean protein extracted from soybean meal using 0.2M NaCl solution at pH 4.5 was passed through a Sephadex G-150 column to isolate 7S globulin. ${\gamma}$-Conglycinin was isolated and purified from the 7S globulin with a DEAE Sephadex A-50 column chromatography. The protein preparation was pure on immunoelectrophoresis, polyacrylamide gel electrophoresis and gel isoelectric fouling. It had an isoelectric point at pH 5.4 and contained 16.12% nitrogen, 4.18% mannose and 1.21% glucosamine. Amino acid composition, in general, shaved that ${\gamma}-conglycinin$ contained higher contents of lysine, dicarboxylic acids and ammonia nitrogen, and lower contents of sulfur-containing amino acids and tryptophan. The subunits of ${\gamma}-conglycinin$ were distributed in the range of pH 4.6-5.5. The subunits located in the pH region of 4.6-5.0 and 5.0-5.5 were glycopeptides (molecular weight of 38,000) and simple peptide (MW of 32,000), respectively.

• Journal of Applied Biological Chemistry
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• v.56 no.2
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• pp.95-100
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• 2013

Soil microbes are important integral components of soil ecosystem which have significant and diverse role in organic matter decomposition, nitrogen cycling, and nitrogen fixation. In this study an effective denaturing gradient gel electrophoresis (DGGE) method was employed for paddy soil microbial diversity survey. For optimum paddy soil microbial DNA extraction, different methods such as Lysis buffer, skim milk bead, sodium phosphate buffer, Epicentre Soil Master DNA extraction kit (Epicentre, USA) and Mo Bio Power Soil DNA kit (MO BIO, USA) methods were utilized. Among all the method, using Mo Bio Power Soil kit was most effective. DGGE analysis of Bacteria was carried out at 6% polyacylamide gel and 45-60% denaturing gradient in the optimal conditions. Whereas DGGE analysis of fungi was done at 6% polyacrylamide gel and 45-80% denaturing gradient in the optimal conditions. By applying the above assay, it was found that variation within the microbial community of paddy soil occurs by a factor of time. DGGE assay used in this study through for a variety of soil microbial analysis suggests the potential use of this method.