• Journal of the Korean Society of Tobacco Science
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• v.13 no.2
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• pp.27-33
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• 1991

Current studies indicated that emphysema in smokers might be due, in part, to the local suppression of G, -protease inhibitor(u, -Pl) in lung by reactive oxygen species in cigarette smoke or smoke-activated lung neutrophiles. In the present works, we examined the possibility that a measure which inactivated $\alpha$l-Pl by cigarette smoke could be an alternative method to evaluate the cigarette quality, In order to determine the inactivation of $\alpha$1, -Pl, trypsin inhibitory capacity(TIC) was assayed. A rapid loss of $\alpha$1, -Pl activity occurred when $\alpha$1-Pl solutions was exposed the gas phase or total particulate matter(TPM) obtained from various brands. The inactivation of $\alpha$1-Pl by gas phase was dependent upon the number of puffs and the age of the smoke. However, that by TPM was rather decreased since 2 puffs and also showed no more change over 24hrs after exposing. Inactivation of $\alpha$1-Pl determined by our suggested method(5 puffs, 24hours of aging after exposing) using various commercial cigarettes exhibited that high tar brands has inactivated it more strongly than low tar cigarettes. But the ability of some brands to inactivate $\alpha$1-Pl does not correlate with the content of tar or nicotine. These results so여esc that the degree of $\alpha$1-Pl inactivation by cigarette smoke may be a useful index for the evaluation of cigarette quality and that it should be also contribute to the manufacture of less hazardous cigarettes.

• Korean Journal of Veterinary Research
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• v.37 no.2
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• pp.359-365
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• 1997

Staphylococcus hyicus subsp. hyicus strains isolated from pigs, chickens and cattle were examined for the production of staphylokinase after inhibition of staphylococcal proteases by two procedures with EDTA(disodium). In one, EDTA was added to the bovine fibrin-dog plasminogen agar medium in concentration of 0.07% and paper strips soaked in 2mg/ml soy bean trypsin inhibitor were then applied on the agar plates. In the other, paper strips soaked in 5% EDTA solution were applied on the bovine fibrin-dog plasminogen agar plates and the strains to be tested were then streaked at right angles with the strip. By these procedures, staphylokinase activity was detected in 8(88.9%) of 9 strains from diseased pigs and in 57(80.3%) of 71 strains from skin of healthy pigs, but not in any strains from skin of healthy chickens and milk samples of mastitic cattle. Additionally kinase activity in 9 Staphylococcus species and subspecies isolated from bovine intramammary infections was also tested by these procedures. Staphylokinase activity was detected in 74.2% of Staph aureus strains and in 25% of Staph xylosus strains.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.3
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• pp.367-375
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• 1998

The physicochemical properties of the $\alpha$-amylase inhibitors from black bean and naked barley is Korea were investigated. Preincubation time for maximum inhibition was 30min and no activity change was seen after that time. Optimum pH of the $\alpha$-amylase inhibitors from the black bean and naked barley was pH 7.0 and the inhibitory activities were stable in the range of pH 6.0~8.0 in both phosphate and Tris-HCI buffer solutions. Both inhibitors maintained more than 50% of activity after incubation for 17 min at 7$0^{\circ}C$. The inhibitors from the black bean and naked barley maintained more than 50% of activities after treatment for 40 min and 30 min with pepsin, and 30 min and 50 min with trypsin, respectively. Both inhibitors functioned via a noncompetitive mechanism and were active against porcine pancreatic and human salivary $\alpha$-amylases. The activities of both inhibitors were linear for the ionic stength ranging from 0 to 0.9. The addition of 70 mM maltose to the reaction mixture caused a maximum increase in the relative activities of both inhibitors, but it did not affect the dissociation of the EI complex. The activities of both inhibitors were significantly enhanced by adding 1mM of K+ or Mg2+.

• Journal of the Korean Chemical Society
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• v.34 no.3
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• pp.288-296
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• 1990

Antielastic fragment in GBⅠ-Ⅱ differ on $P_1$ site with that of antitryptic fragment in LBI. To obtain further understanding of the role of amino acid residue near the reactive site, specificity of $P_1$ site and loop size, Tyr substituted cyclic nonapeptide and cyclic pentapeptide were synthesized and the inhibition constants for some proteinases were calculated by Dixon method. Cyclic nonapeptide showed no inhibition for chymotrypsin but appeared low inhibitory activity for trypsin and elastase and that of cyclic pentapeptide possessed inhibitory activity for chymotrypsin.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.279-279
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• 1994

Fibrinolytic proteases, piscivorase I (PI) and piscivorase II (PII), were isolated from Agkistrodon piscivorus piscivorus (eastern cotonmouth moccasin) venom using gel filtration on Bio-Gel P100 and ion-exchange chromatography on CM-Sepharose. The molecular welghts of two proteases were approximately 23400 and 29000. Their isoelectric points 6.6 and 8.5, respectively. The partial amino acid sequences of PI were characterized by tryptic digestion. PI readily cleaves the A${\alpha}$-and B${\beta}$-chaln of fibronogen, but PII rapidly cleaves A${\alpha}$-chain and more slowly the B${\beta}$-chain, They were activated by Ca$\^$2+/, Mg$\^$2+/ and Ba$\^$2+/, but inhibited by Zn$\^$2+/, Cu$\^$2+/ and Mn$\^$2+/. Two enzymes were also inhibited by cysten, ${\beta}$-mercapto -ethanol, and by metal chelators such as EDTA and EGTA, but not by benzamidine, PMSF, soybean trypsin inhibitor and aprotinin. They did not act like thrombin, plasmin and kallikrein, using specific chromogenllc substrates. Two protease did not induce platelet aggregation. PI showed low hemorrhagic activity at dosage of 50 $\mu\textrm{g}$.

• Journal of the Korean Society of Food Culture
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• v.14 no.5
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• pp.477-485
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• 1999

This study was conducted to improve the functional properties of soybean protein isolate by dimethylglutarylation and acetylation. Amino acid composition and solubility of modified soybean protein by dimethylglutarylation were not changed, but lysine and trypsin inhibitor activity was decreased an isoelectric point was moved from pH5 to pH4 as a result of modification. Emulsification capacity and stability, foaming capacity and thermal stability were increased by the modification. In that 91% dimethylglutarylated protein did not coagulate when heating at $100^{\circ}C$ for 20 min. while its foaming stability was decreased. Whereas specific gravity was decreased by the modification of the soybean protein, relative viscosity and whiteness were improved. Generally, dimethylglutarylation produced more conformational changes in protein system than did in acetylation.

• Parasites, Hosts and Diseases
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• v.40 no.2
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• pp.93-99
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• 2002

The effect of a secretory proteinase from the pathogenic amoebae Acanthamoeba castellanii on host's defense-oriented or regulatory proteins such as immunoglobulins, interleukin-1, and protease inhibitors was investigated. The enzyme was found to degrade secretory immunoglobulin A (slgA), IgG, and IgM. It also degraded $interleukin-1{\alpha}$ ($IL-l{\alpha}$) and $IL-l{\beta}$. Its activity was not inhibited by endogenous protease inhibitors, such as ${\alpha}$2-macroglobulin, ${\alpha}l-trypsin$ inhibitor, and ${\alpha}2-antiplasmin$. Furthermore, the enzyme rapidly degraded those endogenous protease inhibitors as well. The degradation of host's defense-oriented or regulatory proteins by the Acanthanoeba proteinase suggested that the enzyme might be an important virulence factor in the pathogenesis of Acanthamoeba infection.

• The Korean Journal of Mycology
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• v.50 no.1
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• pp.31-40
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• 2022

We aimed to produce a potent β-glucuronidase inhibitor from wild yeast that could inactivate toxic substances in the colon. Culture supernatants and cell-free extracts of non-pathogenic wild yeasts were prepared and their β-glucuronidase inhibitory activities were measured. Cell-free extract from Candida oleophila WP5-19-1 showed the highest β-glucuronidase inhibitory activity (49.0%). The β-glucuronidase inhibitor was maximally produced (IC₅₀ value; 8.4 mg) when C. oleophila WP5-19-1 was cultured in potato dextrose medium containing 5% dextrose (initial pH; 6.0) at 30℃ for 24 hours. β-glucuronidase inhibitor of C. oleophila WP5-19-1 was partially purified by trypsin hydrolysis, ultrafiltration (3 kDa), and Sephadex G-50 filtration. The partially purified β-glucuronidase inhibitor was stable from 30℃ to 60℃ and at pH 6.0 9.0, and showed residual inhibitory activity of about 80%.

• Fisheries and Aquatic Sciences
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• v.21 no.5
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• pp.13.1-13.8
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• 2018

Amyloid plaque, also called senile plaque, the product of aggregation of ${\beta}$-amyloid peptides ($A{\beta}$), is observed in brains of the patients with Alzheimer's disease (AD) and is one of the key factors in etiology of the disease. In this study, hydrolysates obtained from the sea hare (Aplysia kurodai) were investigated for ${\beta}$-secretase inhibitory peptide. The sea hare's muscle protein was hydrolyzed using six enzymes in a batch reactor. Trypsin hydrolysate had highest ${\beta}$-secretase inhibitory activity compared to the other hydrolysates. ${\beta}$-secretase inhibitory peptide was separated using Sephadex G-25 column chromatography and high-performance liquid chromatography on a C18 column. ${\beta}$-secretase inhibitory peptide was identified as eight amino acid residues of Val-Ala-Ala-Leu-Met-Leu-Phe-Asn by N-terminal amino acid sequence analysis. $IC_{50}$ value of purified ${\beta}$-secretase inhibitory peptide was $74.25{\mu}M$, and Lineweaver-Burk plots suggested that the peptide purified from sea hare muscle protein acts as a competitive inhibitor against ${\beta}$-secretase. Results of this study suggest that peptides derived from sea hare muscle may be beneficial as anti-dementia compounds in functional foods or as pharmaceuticals.

• Korean Journal of Pharmacognosy
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• v.35 no.1 s.136
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• pp.52-61
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• 2004

Inhibitory activities of 264 methanol extracts, which were prepared from different parts of 210 kinds of wild and medicinal plants, against human thrombin were evaluated. Based on the anti-coagulation activity determined by thrombin time and activated partial thromboplastin time, the 14 extracts were screened. The fibrinolytic activity, heat stability and inhibition of other proteolytic digestive enzymes, such as pepsin, papain, trypsin and chymotrypsin, of the 14 extracts were further determined, and Ginko biloba (herba), Ephedra sinica (radix), Reynoutria elliptica (herba), Amomum tsao-ko Crevost (fructus), and Magnolia officinalis Rehd. et Wils (bark) were finally selected as possible plant sources for anti-thrombosis agent. These results suggested that medicinal and wild plants could be the potential source of thrombin inhibitor.