• International Journal of Industrial Entomology and Biomaterials
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• v.8 no.1
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• pp.117-121
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• 2004

Soluble proteins of silkworm hemolymph were investigated by means of isoelectric focusing (IEF). The protein spectra during ontogenesis of races and inter-races hybrids kept in Bulgaria was studied. A total of 51 protein bands in the hemolymph from fourth larval instar to imago were ascertained. Stage specific expression was established. The specific expression of some protein bands in the individual spectra manifest phenotype of gene determinate polymorphism (HP F, HP J, HP K, HP L, HP Q - in the zone with pH gradient 3.5-6.2 and HP K, HP L, HP N, HP P, HP T - in the zone with pH gradient 9.5 - 6.2). Breed specific expression was observed. On the basis of the obtained results, it was established that the investigated breeds are heterogeneous and the isoelectric focusing method is successful when specifying the inner-race and inter-race polymorphism in silkworm.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.2
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• pp.139-142
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• 2000

The experiment was carried out to study the variations and geographical distribution of $\beta$-amylase isozyme by isoelectric focusing (IEF) within Korean, Chinese and Japanese soybean land races. In pH 3-10 gel of IEF, the amylase of soybean accessions was separated into low pI group isozymes (TEX>${$Sp_1$}^b$) and high pI group isozymes(${$Sp_1$}^a$). In pH4-6.5 gel, isoelectric points were at 5.07, 5.15, 5.25, 5.40, and 5.94, and h, j, and k bands also were found. The distribution of Sp$_1$$^{a}$ allele (high pI type) was 29.3% in soybean accessions from Korea, 10.1 % in those from China, and 6.9% in Japanese accessions. The percentage of ${$Sp_1$}^a$) allele was the highest in soybean accessions from Kyungsang province (35 %) in Korea, then central China (32 %) in China, and Honshu (10%) in Japan.

• Bulletin of the Korean Chemical Society
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• v.32 no.12
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• pp.4253-4257
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• 2011

Sodium dodecyl sulfate-capillary gel electrophoresis (SDS-CGE) and capillary isoelectric focusing (CIEF) were employed to characterize and compare ricin E purified from the small grain seeds of Ricinus communis with ricin D isoform. During the purification of ricin E using ion-exchange and size-exclusion chromatography, SDS-CGE was found to be useful for monitoring the efficiencies of purification steps. SDS-CGE showed that the molecular size of ricin E was not significantly different from that of ricin D, which was confirmed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. CIEF was useful for discriminating ricin E from ricin D based on their isoelectric points (pI). The pI values of ricin E and D were 8.6-8.8 and 7.0-7.4, respectively. This study demonstrates the usefulness of SDS-CGE and CIEF for the characterization of ricin toxins.

• The Korean Journal of Zoology
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• v.38 no.2
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• pp.294-298
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• 1995

The genetic polymorphism of Protease inhibitor (Pl) in Korean population was investigated by using isoelectric focusing (IEF) in an ultra-narrow pH range,4.2-4.9, and immunoblottins. Three common alleles (Pl * Ml, Pl*2, Pl * M3) were observed and the frequencies for the alleles were Pl * M1=0.7843, Pl * M2=0.1613, Pl * M3=0.0323. In addition to the three common alleles, rare alleles (Pl *5, Pl * Z, Pl* H were detected at low-level frequency. Two unknovlm variants, which were not reported on previous studies in Korean population, were also found.

• Applied Biological Chemistry
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• v.16 no.3
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• pp.112-117
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• 1973

The very low density apolipoproteins were separated by a newly developed method of isoelectric focusing in a narrow pH gradient. Four polypeptides were isolated that differed from the major proteins of the high density or low density lipoproteins. Three of these proteins had indistinguishable amino acid compositions, but different isoelectric points, COOH-terminal alanine, no isoleucine, cysteine or cystine. Two of these polypeptides had $NH_2-terminal$ serine. The polymorphism of apolipoprotein-Ala, so designated from the COOH-terminal residue, was related to sialic acid content; one form contained 2 moles of sialic acid per mole of protein, the second, 1 mole of protein, and the third, no sialic acid. The fourth polypeptide had an amino acid composition different from the first three polypeptides and from other polypetides obtained from very low density lipoprotein. This polypeptide had $NH_2-terminal$ threonine, COOH-terminal resistant to carboxypeptidase A, no histidine, cysteine, cystine or sialic acid. These four polypeptides constituted approx. 40% of the total protein in very low density lipoprotein.

• Asian Journal of Turfgrass Science
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• v.5 no.1
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• pp.11-22
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• 1991

This experiment was executed to investigate the possibility of the application of taxonomic method through the isoelectric focusing with polyacrylamide gel and sodium dodecyl sulfate-polyacrylamide gel electrophoresis with seeds in the identification of turfgrasses. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis was used to investigate the pattern of seed proteins which were extracted from 18 cultivars of cool season turfgrass and 4 cultivars of warm season turfgrass. The isoelectric focusing with polyacrylarnide gel was used to investigate the activity of the three isozymes of esterase, peroxidase and phosphoglucose isomerase which were extracted from 18 cultivars of cool season turfgrass and 4 cultivars of warm season turfgrass. The results were summarized as follows. 1. The difference of the patterns of seed proteins was observed with sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The identification of intra-genus was easily detected. 2. The three isozymes of esterase, peroxidase and phosphoglucose isomerase were investigated through isoelectric focusing with polyacrylamide gel. As a result, esterase was most effective among three isozymes in the identification of turfgrass cultivars 3. In the past cultivar identification was primarily based on visual morphological characters, but there was a lot of difficulty. If we should use electrophoresis, we will be able to identifvturfgrass cultivars more effectively.

• The Korean Journal of Pharmacology
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• v.16 no.2 s.27
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• pp.15-24
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• 1980

[${\alpha}$]-Amylase catalyses the hydrolysis of starch, glycogen, and related poly- and oligosac-charide by random cleavage of ${\alpha}$-D-(l-4) glucan linkage. In man large amounts of amylase are secreted into the digestive tract by the salivary and exocrine pancreatic gland, minimal amount being produced also in other tissues. It has been known that ${\alpha}$-amylase exists in multiple molecular forms, isoenzyme which can be separated from each other because of difference in their physicochemical properties. By using various methods, several groups of investigator have separated the many isoenzyme in serum, saliva and pancreatic juice. Furthermore, changes of the normal serum isoenzyme pattern is diagnostically useful even when the total serum enzyme activity is noninformative, such as the clinical use of isoenzyme of serum lactate dehydrogenase. Procarboxypeptidase-A which is one of the pancreatic enzymes is also present as isoenzymes. Four forms of procarboxypeptidase-A haye been found in the bovine enzyme and three forms of the porcine enzyme. In human pancreatic juice four forms of procarboxypeptidase-A isoenzyme were found by isoelectric focusing method. Recently, the so-called isoamylase analysis was developed for the diagnostic use of amylase in pancreatic diseases. In alcohotic patients, the serum concentration of pancreatic isoamylase is subnormal and this lowered activity provides strong evidence for pancreatic exocrine insufficiency. The purpose of this study was to elucidate the variations of the isoenzyme of amylase and procarboxypeptidase-A in serum, saliva and pancreatic juice of the experimental animals. The results are as follow. 1) Three main forms of isoenzyme of amylase by isoelectric focusing were found in pancreatic juice of normal rabbit. However, many new bands were appeared in the pancreatic juice of cholic acid administered animal intravenously while the infusion of cholic acid or elastase into pancreatic duct produced the decrease of number of the fractions on the isoelectric focusing. In the case of serum isoenzyme from normal animal, two major and a few minor isoamylases were observed. By injecting alcohol intravenousely the fractions of serum isoamylase were significantly decreased and in contrary to the pattern in the pancreatic juice the infusion of cholic acid or elastase into pancreatic duct exhitited a significant decrease of the isoenzyme of amylase fractions. In saliva from normal animal three main isoamylase were produced of the administration of alcohol. 2) In the case of procarboxypeptidase-A isoenzyme, two major fractions which have isoelectric point at 6.2 and 6.4 and other two minor bands were observed in the pancreatic juice of normal rabbit. By the treatment of the juice with trypsin, only one band was produced on the isoelectric focusing. No procarboxypeptidase was appeared on the electrofocusing by the infusion of cholic acid or phospholipase A into the pancreatic duct of rabbit. However, a single major fraction of procarboxypeptidase-A was appeared at 3 hr after simple ligation of the pancreatic duct. No significant changes were observed in the juice of the alcohol or cholic acid administered group.

• Journal of the Korean Society of Food Science and Nutrition
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• v.17 no.4
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• pp.348-357
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• 1988

The present work was undertaken to investigated the purification and characterization of polyphenol oxidase (PPO ; EC 1.10.3.1) in sweet potato, particularly the number of PPO isozymes, and PPO properties such as pH optimum, heat stability, substrate specificity, kinetics, and inhibitor studies. The purification achieved was 23.1 fold from crude extract with a yield of 41.5%. Eight PPO isozymes and twelve PPO isozymes were detected by disc polyacrylamide gel electrophoresis and isoelectric focusing, respectively. The specific activity of each isozyme separated by isoelectric focusing was in the range of $6,000{\sim}46,700U/mg$. This enzyme was sweet below $65^{\circ}C$ and the pH optimum of PPO occurred at 6.0-6.5. The substrate specificity of sweet potato PPO showed the high affinity toward the odiphenolic compounds. Km and Vmax for catechol were found to be 6.7 mM and $20{\triangle}A/min$, me protein, respectively. Inhibitor studies indicated that dithiothreitol was the most potent among the inhibitors used in the present work.

• Korean Journal of Animal Reproduction
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• v.15 no.2
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• pp.149-155
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• 1991

본 실험은 H-Y 항원 유전자 크로닝을 위한 기초연구로서 H-Y 항원의 특성을 규명하기 위하여 친화성 크로마토그래피에 의하여 H-Y 항원을 분리·정제하였다. 정소 추출액을 항체가 결합된 column에 결합시킨 뒤 10% acetic acid로 용출시켰다. 용출된 분획을 모아 농축한 후 HPLC와 SDS-PAGE를 실시하여 H-Y 항원의 분자량은 약 6,7000달톤 임을 알 수 있었으며 isoelectric focusing에 의하여 등전점(pI)은 5.0인 것으로 측정되었다. H-Y 항원에 대한 단일클론항체와 표지항원으로는 H-Y 항원-ABEI(aminobutylethyl isoluminol)를 사용하여 H-Y 항원 정량을 위한 화학발광면역분석법을 개발하였다. 항원항체 반응후 빛의 측정은 NaOH 존재하에서 microperoxidase/H2O2를 이용한 산화반응으로 실시하여 10초간 측정한 빛의 양을 적분하였다. H-Y 항원의 농도와 빛의 양과는 역비례하였으며 감도는 11.8ng/tube 정도이었다.

• Korean Journal of Microbiology
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• v.29 no.3
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• pp.179-183
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• 1991

The whole proteins from 10 different Saccharomyces species were separated by isoelectric focusing, which was carried out in pH gradient polyacrylamide gels with the carrier ampholytes of various pH ranges. About 25 protein bands were found in the gel using pH 3.0-10.0 carrier ampholytes. In gel using pH 4.0-7.0 carrier ampholytes, the protein band of pI 6.3 was found in Sacch. cerevisiae NCYC 478, ATCC 26787, Sacch. rosei and Sacch. uvarum, but it was absent in Sacch. cerevisiae ATCC 24903, ATCC 42949, ATCC 36029, Sacch. steineri var hara, Sacch. bayanus, and Sacch. diastaticus.