• BMB Reports
• /
• v.31 no.1
• /
• pp.106-110
• /
• 1998

We have employed a DNA-native-polyacrylamide gel electrophoresis (DNA-native-PAGE) assay system to characterize the enzyme activity of the endonuclease secreted by human B lymphoblastic IM9 cells. Experimental results clearly demonstrated that the endonuclease activity of IM9 cell culture medium is distinct from that of DNase I in the DNA-native-PAGE assay system. Immunoprecipitation analysis using anti-DNase I antibody showed that the secreted endonuclease is not recognized by the antibody. The secreted endonuclease was estimated using supercoiled plasmid DNA as a substrate. The pH optimum required for the catalytic activity was determined to be in the range of pH 6.6-7.4. No significant difference in the endonuclease secretion was observed by stimulation of the IM9 cells with interferon-${\gamma}$ or interleukin-$1{\beta}$.

• Korean Journal of Pharmacognosy
• /
• v.25 no.1
• /
• pp.47-50
• /
• 1994

For the biological survey, effects of Ailanthi Cortex Radicis, the root bark of Ailanthus altissima(Simaroubaceae) on epoxide hydrolyzing enzymes were checked. The methanolic extract and its chloroform fraction were shown to activate the liver metabolizing enzyme system including epoxide hydrolase system which was monitored by activities of transaminase, lactate dehydrogenase, alkaline phosphatase and epoxide hydrolase system in bromobenzene treated rats. But they showed no effect on glutathione S-transferase activity.

• Bulletin of the Korean Chemical Society
• /
• v.23 no.4
• /
• pp.599-603
• /
• 2002

A selective enzyme-linked immunosorbent assay (ELISA) for the insecticide isofenphos was developed. Three different analogues (haptens) of isofenphos were synthesized and were coupled to carrier proteins through the pesticide thiophosphate group t o use as immunogens or coating antigens. Rabbits were immunized with one of the haptens coupled to BSA for production of polyclonal antibodies and the sera were screened against each of the other two haptens coupled to ovalbumin (OVA). Using the sera of highest specificity, an antigen-coated ELISA was developed, which showed an I50 of 96 ng/mL with the detection limit of 2 ng/mL. The antibodies showed negligible cross-reactivity with other organophosphorus pesticides and the phenol metabolite of isofenphos, which makes the developed assay suitable for the selective detection of isofenphos. An antibody-coated ELISA was also developed, which showed an I50 of 580 ng/mL with a detection limit of 70 ng/mL.

• Mycobiology
• /
• v.39 no.2
• /
• pp.137-139
• /
• 2011

A Vitis hybrid-Vitis coignetiae red wine was vinified by fermentation of a mixture of a Vitis hybrid.Vitis coignetiae must with Saccharomyces cerevisiae KCTC 7904 at $25^{\circ}C$ for 10 days. The Vitis hybrid-Vitis coignetiae red wine showed high antihypertensive angiotensin I-converting enzyme (ACE) inhibitory activity (67.8%) and antioxidant activity (76.7%). The antihypertensive ACE inhibitor in the Vitis hybrid-Vitis coignetiae red wine was partially purified by solid phase extraction chromatography, and its ACE inhibitory activity yielded an $IC_{50}$ of 1.8 mg/mL. Six kinds of oligopeptides, including five new kinds, were contained in the partially purified ACE inhibitor fraction from the red wine after 10 days of fermentation. Antioxidant activity decreased significantly from 76.7% to 40.5% when the post-fermentation period was prolonged to 30 days.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
• /
• 2003.10a
• /
• pp.135.2-135
• /
• 2003

Angiotensin converting enzyme (ACE) converts angiotensin I into angiotensin II by cleaving C-terminal dipeptide of angiotensin I and inactivates bradykinin. ACE inhibitors have been screened from various food sources since the inhibitors decrease blood pressure. Therefore, in this study, an ACE inhibitor was isolated and purified from squid ink using membrane filtration, gel permeation chromatography, normal phase HPLC, and fast protein liquid chromatography. The purified inhibitor was identified to be a molecular mass of 294 by mass spectrometry, and to have IC$\sub$50/ value of 4.9 $\mu\textrm{g}$/mL.

• The Korean Journal of Zoology
• /
• v.36 no.4
• /
• pp.522-528
• /
• 1993

Monoclonal antibodies (MAbs) against human alpha-fetoprotein (AFPI was produced by hybridizing SP 210-Ag 14 mouse myeloma cells with spleen cells of Balb/c mice immunized with purified AFP. Two subclones (D-6 and I-6) were expanded as ascite tumors in svngenic mice, and from ascitic fluid immunoglbulins were Pruified. Each anibodv was identified to be homogeneous by several criteria, and the affinity constant of D-6 and I-6 MAb to AEP was calculated to be 4.2${\times}$10-8 and 6.4${\times}$10-8 M-1, respectively. With these MAbs sensitive and accurate enzyme linked immunosorbent assay method was established.

• Animal cells and systems
• /
• v.2 no.2
• /
• pp.243-248
• /
• 1998

We have partially sequenced glutaminyl cyclases from several mammalian and one avian species and found that the two cysteine residues of the human glutaminyl cyclase are completely conserved. The mammalian glutaminyl cyclase has been reported to possess reactive thiols (Busby, Jr, et aI., 1987, J BioI Chern 262, 8532-8536). Mutagenesis of these cysteine residues, however, resulted in only a slight decrease in enzyme activity. Likewise, the recombinant human enzyme was completely resistant to attempted chemical modification of the putative reactive thiols. Although the human glutaminyl cyclase did not appear to have reactive thiols, it was sensitive to diethylpyrocarbonate and acetylimidazole, indicating the presence of functionally important histidine and tyrosine residues which could act as acid/base catalysts. Almost identical deuterium solvent isotope effect (1.2 vs 1.3) upon the reaction by the human and papaya enzymes, respectively, provides an evidence both animal and plant glutaminyl cyclases catalyze pyroglutamyl-peptide formation by intramolecular cyclization.

• Proceedings of the Korean Society for Applied Microbiology Conference
• /
• 1976.04a
• /
• pp.184.5-184
• /
• 1976

In the course of studies on thermostable liquefying amylase from thermostable Bacillus spp., we have isolated a strain which produces amylase activity. This strain was identified to be Bacillus stearothermophlus. The amylase of this strain demonstrated a maximum activity at 65$^{\circ}C$ and Ca$\^$＋＋/ did not improve thermostability of the enzyme although the erzyme was capable of hydrolyzing starch at temperature of 80$^{\circ}C$ and above. The maximum amount of the enzyme was product at pH 7.0, 50$^{\circ}C$.

• Asian-Australasian Journal of Animal Sciences
• /
• v.18 no.9
• /
• pp.1226-1230
• /
• 2005

The present investigation was undertaken to study the genetic polymorphism of the DRB3 exon 2 in 75 crossbred cattle by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. Five genotypes i.e. HaeIII-a, HaeIII-b, HaeIII-e, HaeIII-ab and HaeIII-ae were observed when the 284 bp PCR products were digested with HaeIII restriction enzyme. The corresponding frequencies of these patterns were 0.53, 0.04, 0.01, 0.38 and 0.04, respectively. Digestion with RsaI restriction enzyme resolved 24 different restriction patterns. The frequencies of these patterns ranged from 0.013 (RsaI-f, RsaI-k and RsaI-c/n) to 0.120 (RsaI-n). The results revealed that the crossbred cows belonged to the RsaI patterns namely b, k, l, a/l, d/s, l/n, l/o and m/n, whose corresponding frequencies were 0.027, 0.013, 0.040, 0.027, 0.040, 0.067, 0.027 and 0.067, respectively. Digestion of the 284 bp PCR product of DRB3.2 gene with PstI in the crossbred cattle did not reveal any restriction site. These results suggested the absence of the recognition site in some of the animals. These results also revealed that the crossbred cows studied were in homozygous as well as heterozygous condition. On the basis of the above results it can be concluded that the DRB3.2 gene was found to be highly polymorphic in the crossbred cattle population.

• Biomolecules & Therapeutics
• /
• v.22 no.5
• /
• pp.414-419
• /
• 2014

Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases that regulate cell-matrix composition and are also involved in processing various bioactive molecules such as cell-surface receptors, chemokines, and cytokines. Our group recently reported that MMP-3, -8, and -9 are upregulated during microglial activation and play a role as proinflammatory mediators (Lee et al., 2010, 2014). In particular, we demonstrated that MMP-8 has tumor necrosis factor alpha (TNF-${\alpha}$)-converting enzyme (TACE) activity by cleaving the prodomain of TNF-${\alpha}$ and that inhibition of MMP-8 inhibits TACE activity. The present study was undertaken to compare the effect of MMP-8 inhibitor (M8I) with those of inhibitors of other MMPs, such as MMP-3 (NNGH) or MMP-9 (M9I), in their regulation of TNF-${\alpha}$ activity. We found that the MMP inhibitors suppressed TNF-${\alpha}$ secretion from lipopolysaccharide (LPS)-stimulated BV2 microglial cells in an order of efficacy: M8I>NNGH>M9I. In addition, MMP inhibitors suppressed the activity of recombinant TACE protein in the same efficacy order as that of TNF-${\alpha}$ inhibition (M8I>NNGH>M9I), proving a direct correlation between TACE activity and TNF-${\alpha}$ secretion. A subsequent pro-TNF-${\alpha}$ cleavage assay revealed that both MMP-3 and MMP-9 cleave a prodomain of TNF-${\alpha}$, suggesting that MMP-3 and MMP-9 also have TACE activity. However, the number and position of cleavage sites varied between MMP-3, -8, and -9. Collectively, the concurrent inhibition of MMP and TACE by NNGH, M8I, or M9I may contribute to their strong anti-inflammatory and neuroprotective effects.