• Title/Summary/Keyword: %EC%B2%B4%EC%A7%88

Search Result 3, Processing Time 0.02 seconds

Purification and Characterization of Lactate Dehydrogenase Isozymes in Channa argus (가물치(Channa argus) 젖산탈수소효소 동위효소들의 정제 및 특성)

  • Park, Eun-Mi;Yum, Jung-Joo
    • Journal of Life Science
    • /
    • v.20 no.2
    • /
    • pp.260-268
    • /
    • 2010
  • The lactate dehydrogenase (EC 1.1.1.27, LDH) isozymes in tissues from Channa argus were purified and characterized by biochemical, immunochemical and kinetic methods. The activity of LDH in skeletal muscle was the highest at 380.4 units and those in heart, eye and brain tissues were 13.4, 3,5 and 5.4 units, respectively. Citrate synthase (EC 4.1.3.7, CS) activity in heart tissue was the highest at 20.7 units. LDH/CS in skeletal muscle, heart, eye and brain tissues were 172.9, 0.6, 0.32 and 0.47. Protein concentration in skeletal muscle tissue was 14.7 mg/g and specific activities of LDH in skeletal muscle, heart, eye and brain tissues were 25.88, 0.79, 0.31 and 1.38 units/mg, respectively. Therefore, skeletal muscle tissue was anaerobic and heart tissue was aerobic. The LDH isozymes in tissues were identified by polyacrylamide gel electrophoresis, immunoprecipitation and Western blot with antiserum against $A_4$, $B_4$, and eye-specific $C_4$. LDH $A_4$, $A_3B$, $A_2B_2$. $AB_3$ and $B_4$ isozymes were detected in every tissue, $C_4$, $AC_3$, $A_2C_2$ and $A_3C$ were detected in eye tissue, and $A_3C$ was found in brain tissue. LDH $A_4$, $A_3B$, $A_2B_2$, $AB_3$, $B_4$, eye-specific $C_4$ isozymes were purified by affinity chromatography and Preparative PAGE Cells. The LDH $A_4$ isozyme was purified in the fraction from elution with $NAD^+$ containing buffer of affinity chromatography. Eye-specific $C_4$ isozyme was eluted right after $A_4$, after which $B_4$ isozyme was eluted with plain buffer. As a result, one part of molecular structures in $A_4$, $B_4$ and eye-specific $C_4$ were similar, but were different from each other in $B_4$ and $C_4$. Therefore the subunit A may be conservative in evolution, and the evolution of subunit B seems to be faster than that of subunit A. The activity of LDH $A_4$, $A_2B_2$, $B_4$, and eye-specific $C_4$ isozymes remained at 39.98, 21.28, 19.67 and 16.87% as a result of the inhibition by 10 mM of pyruvate, so the degree of inhibition was very high. The $Km^{PYR}$ values were 0.17, 0.27 and 0.133 mM in $A_4$, $B_4$ and eye-specific $C_4$ isozymes, respectively. The optimum pH of LDH $A_4$, $B_4$, eye-specific $C_4$, $A_2B_2$, $A_3B$, and $AB_3$ were pH 6.5, pH 8.5, pH 5.5, pH 6.0-6.5, pH 5.0 and pH 7.5. The $A_4$ and heterotetramer isozymes stabilized a broad range of pH. Especially, LDH activities in skeletal muscle tissue were high, resulting in a high degree of muscle activity.LDH metabolism in eye tissue seems to be converted faster from pyruvate to lactate by eye-specific $C_4$ isozyme as eye-specific $C_4$ have the highest affinity for pyruvate, and right after the conversion, oxidation of lactate was induced by $A_4$ isozyme. It was found that expression of Ldh-C, affinity to substrate and reaction time of $C_4$ isozyme were different according to the ecological environmental and feeding capturing patterns.

Enzymatic Properties of Cytidine Deaminase Encoded by cdd Gene in Bacillus subtilis (Bacillus subtilis의 cdd 유전자에 의해 코드되는 Cytidine Deaminase의 효소학적 성질)

  • Song, Bang-Ho;Yoon, Mi-Sook;Kim, Kyung-Hwa;Yeo, Jeung-Sook;Jan Neuhard
    • Microbiology and Biotechnology Letters
    • /
    • v.16 no.6
    • /
    • pp.468-475
    • /
    • 1988
  • The cloned B. subtilis cdd gene encoding cytidine/2'deoxycytidine deaminase (EC 3.5.4.5) was expressed in the cdd deficient B. subtilis mutant ED40. The gene was isolted from the cdd complementing plasmid pSO21, and inserted into the EcoR1/Pvu1 sites of pGB215-110 ΔB, which is a temperature sensitivie E. coli-B. subtilis shuttle vector. In the transformed B. subtilis ED4O harboring the resulting plasmid pSO100, cdd was expressed at several hundred fold elevated levels, and the cytidine deaminase activity in E. coli containing pSO100 was twice the level in B. subtilis/pSO0100. The Km value for cytidine of the partially purified enzyme is 1.88$\times$10$^{-4}$M at pH 7.0 and the V$_{max}$ = 11.1 $\mu$mol/min/mg of protein. The enzyme was completely inhibited by 0.1M mercaptoethanol and HgCl$_2$. The inhibition by p-chrolomercurybenzoic acid showed a Ki = 5 uM. These results suggest that sulfhydryl reagents block an active site thiol group, and/or disturb the formation of the tetrameic holoenzyme.

  • PDF

Suppressive Effect of Green Tea Seed Coat Ethyl Acetate Fraction on Inflammation and Its Mechanism in RAW264.7 Macrophage Cell (RAW264.7 Macrophage Cell에서 녹차씨껍질 에틸아세테이트 분획의 염증억제 효과 및 기전 연구)

  • Noh, Kyung-Hee;Jang, Ji-Hyun;Min, Kwan-Hee;Chinzorig, Radnaabazar;Lee, Mi-Ock;Song, Young-Sun
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.40 no.5
    • /
    • pp.625-634
    • /
    • 2011
  • Green tea seed coat (GTSC) was extracted with 100% ethanol for 4 hr and then fractionated with petroleum ether (PE), ethyl acetate (EtOAC) and butanol (BuOH). The EtOAC fraction showed the highest level in total phenol contents and the lowest level in nitric oxide (NO) production in LPS-stimulated RAW264.7 macrophage cell. Thus, this study was carried out to investigate the anti-inflammatory and its mechanisms of GTSC EtOAC fraction in LPS-stimulated RAW264.7 macrophage cell. GTSC EtOAC fraction contained EGC ($1146.48{\pm}11.01\;{\mu}g/g$), tannic acid ($966.99{\pm}32.24\;{\mu}g/g$), EC ($70.88{\pm}4.39\;{\mu}g/g$), gallic acid ($947.61{\pm}1.03\;{\mu}g/g$), caffeic acid ($37.69{\pm}1.46\;{\mu}g/g$), ECG ($35.46{\pm}3.19\;{\mu}g/g$), and EGCG ($15.53{\pm}0.09\;{\mu}g/g$) when analyzed by HPLC. NO production was significantly (p<0.05) suppressed in a dose-dependent manner with an $IC_{50}$ of $80.11\;{\mu}g$/mL. Also prostaglandin $E_2$ level was also inhibited in a dose-dependent manner. Moreover, iNOS protein expression was suppressed in dose-dependent manner but COX-2 gene expression was not affected. Total antioxidant capacity and glutathione (GSH) levels were enhanced more than the LPS-control. Expressions of antioxidative enzymes including catalase, GSH-reductase and Mn-SOD were elevated compared to LPS-control. Nuclear p65 level was decreased in the GTSC EtOAC fraction in a dose-dependent manner. These results indicate that GTSC EtOAC fraction inhibit oxidative stress and inflammatory responses through elevated GSH levels, antioxidative enzymes expressions and suppression of iNOS expression via NF-${\kappa}B$ down-regulation.