• 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.

• Tribology and Lubricants
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• v.16 no.1
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• pp.22-26
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• 2000

In this paper, the fuction of Zinc-dialkyldithiophosphate (ZnDTP) as an oxidation ingibitor of mineral oils was investigated and compared with 2,6-Di-tert-Butyl-4-Methylphenol (DBMP). Oxidation tests were conducted using an oxygen absorption apparatus. ZnDTP showedanti-oxidation property, and length of induction period prolonged by increasing ZnDTP concentration. The anti-oxidation property of ZnDTP was simmilar to that with DBMP. The amount of hydroperoxide decomposition ability with ZnDTP was much greater than that with DBMP, But the rate constant of radical scavenging with ZnDTP was less than that with DBMP. The anti-oxidation property of ZnDTP seems to by both synergy effect of hydroperoxide decomposition ability and radical scavenging ability.

• Journal of Microbiology
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• v.33 no.2
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• pp.103-108
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• 1995

Streptomyces fradiae protease inhibitor (SFI) was purified effectively by preparative isoelectric focusing and hydroxyapatite chromatography. The molecular weight of SFI was estimated to be 1.7 kDa by SDS-PAGE and 1.8 kDa by molecular sieving HPLC. One hundred and sixty amino acid residues were determined from which molecular weight of SFI was calculated to be 17.054 Da and carbohydrate residue was not detected. SFI was calculated to be 17,064 Da and carbohydrate residue was not detected. SFI was a monomeric protein with two reactive sits, of which isoelectric point was pH 4.1. N-terminal amino acid sequence of SFI had homology with SSI (Streptomyces subsilisin inhibitor) and other protease inhibitors produced by Streptomyces.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.316.2-316.2
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• 2002

Manassantin B classified into dineolignans have been isolated from Saururus chinensis Manassantin B was found to induce apoptosis in human promyelocytic leukaemia HL -60 cells with characteristic apoptotic features like increase of nucleosomalladder. apoptotic body ormation. flipping of membrane phosphatidylserine. Manassantin B induced FAS and FAS ligand expression, and activated caspase 8 which cleaved bid to tbid in cytosol. The release of cytochrome c to sytosol was accompanied with decrease of bcl-2 protein and incresase of tbid and bax protein in mitochondria. Released xytochrome c activated caspase 9 and-3. but these effects were completely attenuated by the treatment of broad caspses ingibitor. Z-VAD fmk. These results indicate that manassatin B induce apoptosis through upregulation of FAS. caspase family and mitochondria-related proteins.

• The Korean Journal of Zoology
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• v.33 no.1
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• pp.119-125
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• 1990

A Potent inhibitor of trypsin and other various serine proteases including chymotrypsin, elastase, kallikrein, plasmin and subtilisin, has been purified to homogeneity from chick skeletal muscle by convendonal chromatographic procedures. The Inhibitor has an apparent molecular weight of 66, 000 dalton as determined by gel filtration. When the purified inhibitor was electrophoresed in the presence of sodium dodecyl sulfate, there appeared rwo protein bands having molecular weights of 66, 000 and 64, 000 dalton. The 64, 000 dalton protein seems to be the product of 66, 000 dalton protein by a lin'ited proteolysis during the purification procedure or in viuo. Thus, it seems to consist of a single polypeptide. The inhibitor appeared to be glycoprotein and have an isoelectric point of 7.4. It contains relatively large amount (8.33 mole%) of cysteine residues.

• Korean Journal of Microbiology
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• v.30 no.5
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• pp.410-414
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• 1992

Numerical identification was carried out for an isolate of Streptomyces strain producing the extracellular p-lactamase inhibitor. Fifty taxonomic unit characters were tested and the data were analyzed numerically using the TAXON program. The isolate was identified to the major cluster 5 of Streptomyces and it was best matched to Streptomyces omiyaensis which is a synonym of Streptomyces exfoliatus. Therefore, it was concluded that the isolate was identified to be a strain (SMF 19) of Streptomyces exjbliatus.

• Applied Biological Chemistry
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• v.40 no.4
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• pp.352-356
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• 1997

To induce the phytoalexins in plant cell culture systems, we surveyed the antimicrobial activity following the feeding of five naphthoquinones in cell cultures of petunia. Among naphthoquinones treated, 2,5,7-trihydroxy-3-(5'-hydroxyhexyl)-1,4-naphthoquinone (3-OH NQ ) was most efficiently absorbed into the cells within 48 hr. The crude extracts of cells treated with 3-OH NQ showed a strong inhibition activity on spore germination of Aspergillus candidus $(MIC:\;32\;{\mu}g/ml)$, whereas the untreated cells showed no activity. The two active compounds, 4,2',4',${\beta}$-tetrahydroxychalcone and 4',7-dihydroxyflavone, were isolated from petunia cells treated with 3-OH NQ. The major phytoalexin, 4,2',4',${\beta}$-tetrahydroxychalcone, inhibited strongly the spore germination of A. candidus $(MIC:\;16\;{\mu}g/ml)$.

• Journal of Life Science
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• v.7 no.3
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• pp.228-233
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• 1997

A thiol protease has been isolated and partially purified from encysted brine shrimp Artemia franciscana using a four-step procedure(filtration, salting out, gel filtration and ion exchange chromatography). The optimum pH of the enzyme for caseinolytic activity was appeared to be 3.0, and the enzymematic activity was stable up to pH 6.0 but lost completely at the pH higher than 8.0. The optimal temperature of the enzyme was appeared to be 35$^{\circ}$C, and ninety percent of the enzyme activity was lost at 45$^{\circ}$C. Various metal ions, e.g., zinc, copper, iron, inhibited the enzyme activity; however, heavy metal chelator, e.g., EDTA, stimulated the enzyme activity. The protease was concluded to be a member of the thiol group protease, since it was inhibited by thiol protease inhibitors and iodoacetate. The protease was also concluded to be a acid protease based on optimum pH.

• Development and Reproduction
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• v.2 no.1
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• pp.9-20
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• 1998

It has been wel known that phospholipase C(PLC) plays an important role in the intracellular signaling in a variety of cell types. However, involvement of PLC in mouse oocyte maturation and preimplantation embryo development remains unknown. The present study examined the expression patterns of the mouse PLC \beta 1 and \gamma 1 during oocyte maturatio and preimplantation embryo development study examined the expression patterns of the mouse PLC \beta 1 and \gamma 1 during oocyte maturation and preimplantation embryo development by the competitive reverse transcription-polymerase chain reaction (RT-PCR method). PLC \gamma 1 mRNA (0.1 fg) was readily detected in germinal vesicle (GV)-stage oocyte and its level was reduced as meiotic resumption proceeded. PLC-\beta 1 mRNA (<0.1 fg) as detected at low level at GV-stage oocytes and scarcely detected at germinal vescle breakdown (GVBD)-stage oocytes. After fertilization, both PLC \beta 1 and \gamma 1 mRNA levels began to increase at morula-stage embryos (0.2 fg) and were more prominent in blastocyst-stage embryos(1 fg). to elucidate the possible involvement of PLC via protein kinase C(PKC) pathway during oocyte maturation and preimplantation embryo development , the effects of sphingosine (PKC inhibitor), sn-$diC_{8}$(PKC activator) anc U73122 (PLC ingibitor) were examined. Treatment of GV-stage oocytes with sphingosine (20 \mu M) facilitated the meiotic resuption by 10-20 over the control within 1 h as judged by GVBD, whereas U73122 failed to show any significant effect. U73122 (10 \mu M) effectively blocked the compaction of morula, while sn-$diC_{8}$(50 \mu M). In summary, the present study shows that the mouse PLC \beta 1 and \gamma 1 are expressed in a developmental stage-specific manner and PLC-PKC pathway may be involved in early preimplantation embryo development.