• 대한약리학회지
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• 제25권1호
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• pp.75-85
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• 1989

면역 보체가 결합되어 있는 zymosan에 의하여 활성화된 다형핵 백혈구에서 세포 투과성 물질인 N-ethylmaleiamide과 $Hg^{++}$은 superoxide 라디칼 생성, NADPH oxidase 활성도 및 lysosomal enzyme (lactic dehydrogenase, ${\beta}-glucuronidase$)의 유리를 억제하였다. 세포막 단백에 특이적인 p-chloromercuribenzoic acid와 p-chloromercuribenzenesulfonic acid는 superoxide 라디칼 생성에 영향을 주지 않았으나 NADPH oxidase 활성도와 lysosomal enzyme의 유리를 억제하였다. 식작용 중에 세포막과 세포내의 sulfhydryl기는 반응시간에 따라 점진적으로 감소하였다. N-ethylmaleiamide와 $Hg^{++}$은 세포막과 세포내의 sulfhydryl기를 모두 감소시켰다. P-Chloromercuribenzoic acid와 p-chloromercuribenzenesulfonic acid는 세포막의 sulfhydryl기를 유의하게 감소시켰으나 세포내 용해성 sulfhydryl기에는 영향을 주지않았다. Cysteine과 mercaptopropionylglycine는 superoxide 라디칼의 생성과 lysosomal enzyme의 유리를 억제하였다. Gluthathione은 superoxide생성에 영향을 주지 않았으나 뚜렷하게 lactic dehydrogenase의 유리를 억제하였다. N-ethylmaleiamide에 의한 superoxide 생성의 억제는 cysteine과 mercaptopropionyl-glycine에 의하여 반전되었으나 gluthathione의 영향은 없었다. N-ethylamleiamide에 의한 NADPH oxidase의 비활성화는 gluthathione, cysteine과 mercaptopropionylglycine에 의하여 저해되었다. Carbachol에 의하여 항진된 superoxide 라디칼 생성은 N-ethylamleiamide에 의하여 완전히 억제되었고, atropine에 의하여 길항되었다. 그러므로, 외부 자극에 대한 다형핵 백혈구 반응의 표현은 sulfhydryl기의 양의 변화와 연관이 있을 것으로 시사되었다. Lysosomal enzyme 유리는 세포막과 세포내의 sulfhydryl기에 의하여, 이에 반하여 superoxide생성은 세포내 sulfhydryl기에 의해서 영향받을 것으로 추정되었다.

• Archives of Pharmacal Research
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• 제16권1호
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• pp.1-5
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• 1993

The reaction of sulfhydryl groups in human serum ablumin with bacteriostatic and hypotensive notrosating agents such as sodium nitorprusside and sodium nitrite has been examined. The low reactivity of sodium nitroprusside to sulfhydral groups in albumin has been observed and the sterical inaccessilibility of the agent site which sulfhydryl group resides was implicated. The reaction of sodium nitrite with albumin was highly influenced by pH and little reactivity was observed at physiological pH. On the other hand, the reaction between albumin and S-nitrosoglutatione, an intermediate induced from the reaction of glutathione and nitrosating agents, resulted in the rapid decrease of free sulfhydryl groups in albumin. S-Nitrosylation of the sulfhydryl group by S-nitrosoglutathione and the subsequent production of mixed disulfide is the probable route of modification. In the physiological system, S-nitroso-glutathione may act as an active intermediate in expressing reacivity of nitrosating agents to sulfhydryl groups in albumin.

• The Korean Journal of Physiology
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• 제19권2호
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• pp.155-160
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• 1985

Dantrolene sodium(DS) is a long acting skeletal muscle relaxant which has been successfully used to control muscle spasticity in patients with various neurological disorders. However, its use is associated with hepatotoxicity. Tissue sulfhydryl group has many important roles for cellular integration and glutathione serves as a substrate for the detoxification metabolism. The purpose of this study were to investigate the effect of DS on tissue sulfhydrl group and glutathione content. Foully albino rats were divided into two groups ; saline treated (control) and DS treated groups. DS dissolved in saline was administered orally. All rats were sacrificed after 7. 14. 21 and 28 days of DS ana saline treatment by dacapitation ana liver was removed for the enzyme preparation. Total and nonprotein sulfhydryl were measured by the method of Sedlak and Lindsay (1968). Total glutathione content was assayed according to the method described by Tietze (1969) and glutathione reductase was assayed according to the method of Racker (1955), The results obtained are summarized as follows : DS administration significantly depressed the total, protein and nonprotein sulfhydryl content in liver. There were significant reduction of both total glutathione content and glutathione reductase activity in liver. On the basis of the above results it may be speculated that the toxicity of DS are well correlated with tissue sulfhydryl content and glutathione reductase activity.

• 유기물자원화
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• 제1권1호
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• pp.115-125
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• 1993

Euglena gracilis 에서 arginine deiminas는 mitochondrial matrix 내에 존재한다. 고도로 정제된 효소가 0.23 nM의 $K_m$ 값을 갖고 효소반응을 하기 위해서는 $Co^{2+}$가 필요하며, 이때 최적 pH는 9.3~10.3이었다. Gel filtration에 의해서 얻어진 조효소 단백질의 분자량은 87,000이었으며, SDS-acrylamide gel electrophoresis에 의해 효소는 48,000의 분자량을 갖는 2개의 동일한 subunit로 구성되어 있음이 밝혀졌다. Euglena의 arginine deiminas는 sulfhydryl inhibitors에 의해서 활성이 저지되었는데, 이는 sulfhydryl group이 효소의 활성부위에 관여함을 나타낸다. 이 sulfhydryl group은 arginine이 효소와 결합하는데 있어서 negative cooperativity를 나타내었다. ${\beta}-guanidinopropionate$, ${\gamma}-guanidinobutyrate$와 guanidinosuccinate는 효소의 활성을 저지시키지 않는데 반하여, $L-^{\alpha}-amino-{\beta}-guanidino-propionate$, D-arginine, 그리고 L-homoarginine은 효소의 활성을 강력하게 저지시켰다. Citrulline과 ornithine에 의해서도 상당한 정도의 효소활성저지가 관찰되었다. 우리는 Euglena의 arginine deiminase의 독특한 성질이 Euglena 라는 원생동물 내에서 arginine 대사의 조절에 어떻게 영향을 미치는지를 토의하고자 한다.

• 한국축산식품학회지
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• 제39권4호
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• pp.576-584
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• 2019

This study was performed to evaluate the physicochemical properties of myofibrillar protein (MP) gels containing pork skin gelatin at different salt concentrations. MP gels were prepared to the different salt levels (0.15, 0.30, and 0.45 M) with or without 1.0% of pork skin gelatin. Cooking yield (CY), gel strength, shear stress were measured to determine the physical properties, and SDS-polyacrylamide gel electrophoresis, scanning electron microscopy, fourier transform infrared spectroscopy, sulfhydryl group and protein surface hydrophobicity was performed to figure out the structural changes among the proteins. The addition of gelatin into MP increased CYs and shear stress. MP at 0.45 M salt level had the highest CY and shear stress, as compared to MPs at lower salt concentrations. As the salt concentration of MP gels increased, the microstructure became the compact and wet structures, and decreased the amount of ${\alpha}-helix$/unordered structures and ${\beta}-sheet$. MP with gelatin showed a decreased amount of ${\alpha}-helix$/unordered structures and ${\beta}-sheet$ compared to MP without gelatin. The addition of gelatin to MP did not affect the sulfhydryl group, but the sulfhydryl group decreased as increased salt levels. MP mixtures containing gelatin showed a higher hydrophobicity value than those without gelatin, regardless of salt concentration. Based on these results, the addition of gelatin increased viscosity of raw meat batter and CY of MP gels for the application to low salt meat products.

• Journal of Acupuncture Research
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• 제19권5호
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• pp.209-218
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• 2002

Objective : This study was undertaken to examine whether Carthami Semen aquacupuncture (CSA) exerts protective effect against Hg-induced cell injury in rabbit liver. Methods : The cell injury was evaluated by ALT activity and lipid peroxidation was estimated by measuring malondialdehyde (MDA). Results : Hg caused an increase of ALT activity and lipid peroxidation in a dose-dependent-manner over concentrations of 0.1-1 mM, which were prevented by addition of 0.005% CSA. The protective effect of CSA was dose-dependent in concentration range of 0.001 to 0.01%. The increase of ALT activity and lipid peroxidation induced by 0.5 mM Hg were almost completely decreased by addition of 0.01% CSA. When the liver tissues were exposed to 0.5 mM Hg, GSH content was decreased, which was significantly restored by 0.01% CSA. 0.5 mM Hg caused decrease in the amount of total and nonprotein sulfhydryl groups, and 0.01% CSA prevented Hg-induced reduction of nonprotein sulfhydryl group but not protein sulfhydryl group. Conclusions : These results suggest that CSA exerts protective effect against Hg-induced cell injury by antioxidant action resulting from enhancement of nonprotein sulfhydryl group content including GSH in liver.

• The Korean Journal of Physiology
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• 제25권2호
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• pp.179-188
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• 1991

Effect of a sulfhydryl reagent, p-chloromercuribenzoic acid (PCMB), on the transport of succinate was studied in brush border (BBMV) and basolateral (BLMV) membrane vesicles isolated from rabbit renal cortex. PCMB induced an irreversible inhibition of the $Na^+-dependent$ succinate uptake in a dose-dependent manner with $IC_{50}$ of 55 and $65\;{\mu}M$ in BBMV and BLMV, respectively. The inhibitory effect of PCMB was prevented by a pretreatment of vesicles with dithiothreitol. PCMB did not increase $Na^+$ permeability at concentrations inhibiting succinate uptake. The PCMB inhibition of succinate uptake was due to a change in Vmax, but not in Km. When membrane vesicles were pretreated with PCMB in the presence of unlabelled succinate, the inhibitory effect was significantly reduced. In both BBMV and BLMV, succinate uptake was inhibited by various sulfhydryl reagents with the inhibitory potency of following order: $HgCl_2$>DTNB>PCMBS>PCMB. These results suggest that sulfhydryl groups are essential for dicarboxylate transport and that they may be located at or near substrate binding sites of the transporters in renal brush border and basolateral membranes.

• The Korean Journal of Physiology
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• 제9권1호
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• pp.1-11
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• 1975

The present experiments were carried out to investigate the active center of sodium and potassium ion activated adenosine triphosphatase. An ATPase, activated by sodium ion Plus potassium ion in the presence of magnesium ion, and inhibited by ouabain, has been obtained from rabbit red cell ghosts. The ATPase activity was measured by inorganie phosphate released from ATP. From this values of the measured inorganic phosphate, the activity of ATPase was calculated. The following results were observed. 1. The activity of $(Na^++K^+)-ATPase$ is inhibited by ouabain. This effect may not be due to an effect on sulfhydryl groups, amino groups, carboxyl groups, imidazole groups and hydroxyl groups. 2. The $(Na^++K^+)$-activated enzyme system is inhibited by p-chloromercuribenzoate and by d nitroflurobenzene, and this effect may be due to an effect on sulfhydryl groups. These results indicate that the sulfhydryl groups is attached to sodium-potassium dependent adenosine triphosphate, an aspect of the pump. 3. The $(Na^++K^+)-activated$ enzyme system is inhibited by maleic anhydride and this inhibition is reversed by lysine. This Seems to indicate that the active center of this enzyme is the amino groups. 4. The $(Na^++K^+)$-activated enzyme system is inhibited by iodoacetamide and this inhibition is reversed by the simultaneous present of cysteine and aspartic acid in the suspension medium. This result indicates that this enzyme contains sulfhydryl groups and carboxyl groups. 5. The $(Na^++K^+)-ATPase$ activity is accelerated by adrenaline and this effect is abolished by aspartic acid. This effect of aspartic acid indicate that carboxyl group might be involved in the hydrolysis of ATP by the enzyme system. On the hydrolysis of ATP by the enzyme system. On the basis of these experiments it f·as suggested that the active center of $(Na^++K^+)-activated$ ATPase contains sulfhydryl groups, amino groups and carboxyl groups.

• BMB Reports
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• 제30권2호
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• pp.113-118
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• 1997

Aspartase from Hafnia alvei was inactivated by N-ethylmaleimide (NEM) and 5,5' -Dithiobis-(2-znitrobenzoic acid) (DTNB) following pseudo-first order kinetics. Their apparent reaction orders were 0.83 and 0.50 for NEM and DTNB modifications, respectively, indicating that inactivation was due to a sulfhydryl group in the active site of aspartase and participation of the sulfhydryl group in an essential step in the catalytic reaction. When aspartase was modified by DTNB, the enzyme activity was restored by dithiothreitol treatment, indicating that cysteine residuetsl islarel possibly at or near the active site. The pH-dependence of the inactivation rate by NEM suggested that an amino acid residue having pK value of 8.3 was involved in the inactivation. When aspartase was incubated with NEM and L-aspartate together, L-aspartate markedly protected the enzyme from inactivation by NEM, but the other reagents used did not.

• Journal of Acupuncture Research
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• 제22권2호
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• pp.123-132
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• 2005

Melittin,cationic 26-amino acid, is the principal component of the bee venom (BV) which has been used for treatment of inflammatory disease such as arthritis rheumatism NF-kB is activated by subsequent release of inhibitory IkB via activation of a multisubunit IkB kinase (IKK). We previously found that melittin bind to the sulfhydryl group of p50, a subunit of NF-kB. Since sulfhydryl group is present in kinase domain of IKKa and IKKb, melittin could modify IKK activity by protein-protein interaction. We therefore examined effect of melittin on IKK activities in sodium nitroprusside (SNP)-stimulated synoviocyte obtained from RA patients. Melittin suppressed the SNP-induced release of IkB resulted in inhibition of DNA binding activity of NF-kB and NF-kB-dependent luciferase activity. Consistent with the inhibitory effect on NF-kB activation, IKKa and IKKb activities were also suppressed by melittin. Surface plasmon resonance analysis realized that melitin binds to IKKa $(Kd\;=\;1.34{\times}10-9M)$ and IKKb$(Kd\;=\;1.0{\times}10-9M)$. Inhibition of IKKa and IKKb resulted in reduction of the SNP-induced production of inflammatory mediators NO and PGE2 generation. The inhibitory effect of melittin on the IKKs activities, binding affinity of melittin to IKKs, and NO and PGE2 generation were blocked by addition of reducing agents dithiothreitol and glutathione. In addition, melittin did not show inhibitory effect in the transfected Synoviocytes with plasmid carrying dominant negative mutant IKKa (C178A) and IKKb (C179A). These results demonstrate that melittin directly binds to sulfhydryl group of IKKs resulting in IkBrelease, thereby inhibits activation of NF-kB and expression of genes involving in the inflammatory responses.