• The Korean Journal of Physiology
• /
• v.8 no.1
• /
• pp.45-53
• /
• 1974

The effects of kanendomycin on the potassium permeability in the rabbit erythrocyte membrane are investigated and the results are summarized as follows. 1. Kanendomycin causes the efflux of $K^+\;and\;influx\;of\;Na^+$ across the rabbit erythrocyte membrane. 2. Osmotic resistance of kanendomycin treated erythrocytes is diminished. This diminution of osmotic resistance is more pronounced by increasing concentration of kanendomycin and longer incubation time. But osmotic resistance is rather increased in the presence of lower concentration of kanendomycin. 3. Cysteine and glutathione have little influence on $K^+$ efflux induced by kanendomycin. 4. EDTA has no effect on the increase in $K^+$ outflux by kanendomycin while PCMB augments slightly on $K^+$ outflux. 5. Kanendomycin inhibits $Ca^{++}$ binding competitively to rabbit erythrocyte membrane fragments.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.28 no.5
• /
• pp.1010-1016
• /
• 1999

Protease related mold was isolated and selected as a starter culture for commercial production of meju. Isolated microorganism was identified as Syncephalastrum racemosum PDA 132 2. To obtain basic data about protease for production of soybean peptides and application of the strain in meju fermentation, we extrated and purified protease and charateristics of the enzyme were investigated. The optimum condition for the production of enzyme was pH 4.0, 30oC, 5 days. The protease was purified 19.7 folds by gel filtration and ion exchange chromatography and specific activity was 12.4unit/mg. The purified enzyme was 34kDa in size, thiol protease(100% inhibited by PCMB), and was acidic protease(stable between pH 2.0~5.0). Vmax of the enzyme was 2.14 g/min which was lower(1/50) than that of by Asp. wentti and B. subtilis.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.6 no.1
• /
• pp.27-33
• /
• 1977

The alkaline protease was isolated from the culture of Penicillium species (P-46) grown in the wheat bran media. The crude purification of this enzyme was carried out by extraction with distilled water and precipitated with 0.7-saturated ammonium sulfate, then dialysis for 3days. The activity of this enzyme was determined by Folin's colorimetric method. The results were as follows; 1. The optimum pH and temperature of this enzyme were pH 8.4 and $45^{\circ}C$. 2. This enzyme was stable at pH $7.0{\sim}9.0$. 3. This enzyme was not inactivated by treatment in lower temperature than $30^{\circ}C$. 4. The activity of this enzyme was strongly inhibited by $Hg^{++}$ and $Cu^{++}$, but slightly by $Ag^+$ 5. This enzyme was not inhibited by cystein, thiourea, ${\varepsilon}-aminocaproic$ acid, 2, 4-DNP, EDTA but strongly inhibited by PCMB.

• Microbiology and Biotechnology Letters
• /
• v.1 no.2
• /
• pp.99-104
• /
• 1973

A study on the active center of the acid protease from Penicillium sp. was conducted, and also the milk clotting activity of acid prorease was measured. 1. PCMB failed to influence the proteolytic activity of acid protease, indicating that a reactive sulfhydryl group is not required for the enzymatic activity. 2. $\varepsilon$-amino caproic acid did not show any inhibitory effect on tile proteolytic activity of acid protease. 3. Also 2, 4-dinitro phenol did not show any inhibitory effect on the enzyme activity. 4. Acid protease from Penicillium sp. showed a strong milk clotting activity in the presence of Ca ion. 5. This enzyme had a strong proteolytic activity on various substrate, such as casein, denatured hemoglobin, ovalbumin, denatured bovine muscle protein, denatured percine muscle protein and denatured chicken muscle protein.

• Korean Journal of Food Science and Technology
• /
• v.36 no.3
• /
• pp.440-447
• /
• 2004

Characteristics of human ${\beta}-carotene$ 15,15'-dioxygenase isolated by recombinant DNA technology was elucidated. Optimal pH and temperature were 9.0 and $40^{\circ}C$, respectively. Enzyme activity was temperature-sensitive. Enzyme was stable at pH 6.0-9.0 for 24 hr and under $5^{\circ}C$. Half-life of enzyme at $35^{\circ}C$ was 40 min. Crude preparations of enzyme were inhibited by ferrous ion-chelating agent and sulfhydryl-binding agent. GSH offsets inhibitory effect of PCMB. With increasing substrate concentrations, enzyme activity gave typical Michaelis-Menten curve, Based on Hanes-Woolf plot of data, $K_{m}\;and\;V_{max$ were $3.39{\times}10^{6}\;M\;and\;1.2\;pmol/mg$ protein/min, respectively.

• The Korean Journal of Pharmacology
• /
• v.28 no.1
• /
• pp.91-102
• /
• 1992

In $Ca^{++}$ containing media, arachidonic acid markedly stimulated superoxide and $H_2O_2$ generation and activated NADPH oxidase. In $Ca^{++}$ free media, stimulatory action of arachidonic acid on NADPH oxidase was not detected. Arachidonic acid-stimulated respiratory burst was inhibited by EGTA, TMB-8, verapamil, diltiazem, nifedipine, dibucaine, lidocaine, CCCP, 2,4-dinitrophenol, sodium arsenate, chlorpromazine, theophylline, $HgCl_2$, PCMB and PCMBSA but not affected by tetrodotoxin, tetraethylammonium chloride and procaine. EGTA almost completely inhibited release of ${\beta}-glucuronidase$ by arachidonic acid and verapamil, CCCP and theophylline slightly inhibited it, whereas dibucaine did not show any significant effect. Arachidonic acid induced $Ca^{++}$ release from intact neutrophils and it was decreased by TMB-8. Arachidonic acid-induced elevation of intracellular free $Ca^{++}$ level was inhibited by EGTA and CCCP and slightly inhibited by TMB-8. Amount of intracellular free $Ca^{++}$ increased by either arachidonic acid plus verapamil or arachidonic acid plus dibucaine was greater than that by arachidonic acid alone. These results suggest that various changes of biochemical events may be implicated in the functional expression in neutrophils activated by arachidonic acid. Arachidonic acid appears to elevate cytosolic free $Ca^{++}$ level by stimulating $Ca^{++}$ release from intracellular $Ca^{++}$ storage sites. During activation of neutrophils, $Ca^{++}$ influx and efflux may be accomplished, simultaneously.

• BMB Reports
• /
• v.28 no.5
• /
• pp.408-413
• /
• 1995

Decrease in the amount of cotyledonary spermidine in Glycine max under anaerobic conditions related to an increase in spermidine dehydrogenase. Under the same conditions, no enzymatic activity of diamine oxidase was observed. Exposure of Glycine max both to spermidine and 1,3-diaminopropane under anaerobic conditions resulted in a decrease in spermidine contents. Correlated with the decrease in spermidine contents, there was a drastic increase in spermidine dehydrogenase. The molecular weight of the purified enzyme estimated by Sephacryl S-300 gel column and SDS gel electrophoresis were 130,000 dalton and 65,000 dalton, respectively, indicating that the enzyme is a dimer. The optimal pH for activity was 9.3. The $K_m$ value for spermidine was 0.61 mM. Neither metal ions nor polyamine and derivatives affected enzymatic activity, but the enzyme was inhibited by DTNB, NEM and PCMB, suggesting that a cysteine residue of the enzyme is associated with or involved in enzyme activity. To our knowledge, this is the first report describing properties of the enzyme from plants. Considered together, the data in this paper indicate that both spermidine and 1,3-diaminopropane, novel activators, enhance the spermidine dehydrogenase activity and control the intracellular spermidine contents.

• The Journal of Internal Korean Medicine
• /
• v.19 no.1
• /
• pp.431-441
• /
• 1998

This study was undertaken to determine whether Buthus exract(BTE) affects Na^+-K^+-ATPase$ activity of nervous tissues. The enzym activity was measured in synaptosomal fraction prepared from rabbit brain cortex. Na^+-K^+-ATPase$ activity was inhibited by BTE over concentration range of 0.05-0.5% in a dose-dependent manner. The enzyme activity was increased by an increase in $Na^+$ concentration from 5 to 100mM, $K^+$ concentration from 0.5 to 10mM, and $Mg^{2+}$ concentration from 0.2 to 5mM. These changes in ion concentrations did not produce any effect on the inhibitory effect of BTE on $Na^+-K^+-ATPase$ activity. An increase in ATP concentration from 0.1 to 3mM caused an increase in the enzyme activity. The inhibition of the enzyme activity by BTE were not different between two ATP concentrations. A sulfhydryl group protector DTT prevented PCMB-induced inhibition of $Na^+-K^+-ATPase$ activity, but the BTE-induced inhibition was not altered by DTT. The inhibition of enzyme activity by combination of ouabain and BTE was not different from that by Buthus alone. These results suggest that Buthus exerts inhibitory effect on $Na^+-K^+-ATPase$ activity in cerebral synaptosomes, and the action mechansim is similar to that of ouabain.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.18 no.3
• /
• pp.348-355
• /
• 1989

This experiment was conducted to investigate the characteristics of alkaline protease from Aspergillus fumigatus which was isolated from soil as a superior strain for the production of the alkaline protease. The optimum temperature for enzyme activity was $50^{\circ}C$ and optimum pH was 9.0. The enzyme was stable at pH 8.0 to 10.0 and thermal inactivation was shown $30^{\circ}C$. The activity of the enzyme was increased by the addition of $Mn^{++},\;Cu^{++},\;Ba^{++},\;Mg^{++},\;$wheras it was inhibitied by $K^+,\;Fe^{+++},\;Ag^+,\;Pb^{++},\;Na^+,\;Ca^{++},\;Hg^+,\;Zn^{++}$. EDTA. 2, 4-DNP, ${\varepsilon}-amino$ caproic acid did not show inhibitory effect on the proteolytic activity of alkaline protease but P-chloromercuribenzoic acid inhibited the enzyme activity, indicating that reactive sulfhydryl group is required for the enzymatic activity. The reaction of this enzyme followed typical Michael-Menten Kinetics with the Km value of $8.33{\times}10^{-4}mole/{\ell}$ with the Vmax of $47.62{\mu}g/min$. This enzyme had stronger proteolytic activity than trypsin on substrate such as casin and hemoglibin.

• The Korean Journal of Physiology
• /
• v.30 no.1
• /
• pp.53-62
• /
• 1996

Transepithelial transport of tetraethylammonium (TEA) was studied in monolayers of opossum kidney cells cultured on permeable membrane filters. $[^{14}C]-TEA$ was transported across the OK cell monolayer from basolateral to apical side by a saturable process which can be stimulated by acidification of the apical medium. The apparent Michaelis-Menten constant $(K_{m})$ and the maximum velocity$(V_{max})$ for the transport were $41\;{\mu}M$ and 147 pmole/ mg protein/ min, respectively. The transport was significantly inhibited by unlabelled TEA, amiloride, cimetidine, choline, and mepiperphenidol added to the basolateral side at 1 mM and was slightly inhibited by 5 mM $N_{1}-methylnicotinamide\;(NMN).$ Unlabelled TEA added to the apical side stimulated the $basolateral-to-apical\;{^{14}C}-TEA$ transport, suggesting that the TEA self-exchange mechanism was involved at the apical membrane. Sulfhydryl reagents such as ${\rho}-chloromercuribenzoic\;acid\;(PCMB)\;and \;{\rho}-chloro-mercuribenzene\;sulfonate \;(PCMBS)$ and carboxyl reagents such as N,N'-dicyclohexylcarbodiimidem (DCCD) and N-ethoxy-carbonyl-2-ethoxy-1,2-dihydro-quinoline(EEDQ) inhibited the TEA transport at both the basolateral and apical membranes of the OK cell monolayer. These results suggest that OK cell monolayers possess a vectorial transport system for organic cations which is similar to that for organic cation secretion in the renal proximal tubule.