• The Korean Journal of Physiology and Pharmacology
• /
• 제7권1호
• /
• pp.15-23
• /
• 2003

Cellular redox state is known to be perturbed during ischemia and that $Ca^{2+}$ and $K^2$ channels have been shown to have functional thiol groups. In this study, the properties of thiol redox modulation of the ATP-sensitive $K^2$ ($K_{ATP}$) channel were examined in rabbit ventricular myocytes. Rabbit ventricular myocytes were isolated using a Langendorff column for coronary perfusion and collagenase. Single-channel currents were measured in excised membrane patch configuration of patch-clamp technique. The thiol oxidizing agent 5,5'-dithio-bis-(2-nitro-benzoic acid) (DTNB) inhibited the channel activity, and the inhibitory effect of DTNB was reversed by dithiothreitol (disulfide reducing agent; DTT). DTT itself did not have any effect on the channel activity. However, in the patches excised from the metabolically compromised cells, DTT increased the channel activity. DTT had no effect on the inhibitory action by ATP, showing that thiol oxidation was not involved in the blocking mechanism of ATP. There were no statistical difference in the single channel conductance for the oxidized and reduced states of the channel. Analysis of the open and closed time distributions showed that DTNB had no effect on open and closed time distributions shorter than 4 ms. On the other hand, DTNB decreased the life time of bursts and increased the interburst interval. N-ethylmaleimide (NEM), a substance that reacts with thiol groups of cystein residues in proteins, induced irreversible closure of the channel. The thiol oxidizing agents (DTNB, NEM) inhibited of the $K_{ATP}$ channel only, when added to the cytoplasmic side. The results suggested that metabolism-induced changes in the thiol redox can also modulate $K_{ATP}$ channel activity and that a modulatory site of thiol redox may be located on the cytoplasmic side of the $K_{ATP}$ channel in rabbit ventricular myocytes.

• 폴리머
• /
• 제27권4호
• /
• pp.330-339
• /
• 2003

폴리(스티렌-co-디비닐벤젠) 수지 페닐고리의 클로로메틸화를 통해 메틸렌티올기를 도입한 수지 (I), 폴리(스티렌-co-메틸 메타아크릴레이트-co-디비닐벤젠) 공중합체의 페닐고리와 에스터기에 클로로메틸화 반응을 거쳐 각각 메틸렌티올기를 도입하여 중금속 이온들과의 배위결합에 필요한공간개념을 배려한 수지(II) 및 폴리(스티렌-co-디비닐벤젠) 수지의 페닐고리를 클로로설폰화한 후, 소디움하이드로술파이드로 티오설폰산화한 수지 (III) 등 3가지 종류의 티올계 구상형 수지들을 합성하였다. 이어, 이들 킬레이트 수지들에 대한 중금속 이온의 흡착경향을 평가한 결과, 티올기 함유 I형 킬레이트 수지는 Hg$^{2＋}$에 대해서만 선택적 흡착성을 보였고, 티올기 함유 II형 킬레이트 수지는 Hg$^{2＋}$에 대한 흡착성능이 보다 향상되었으며, Cu$^{2＋}$, Pb$^{2＋}$, C$d^{2＋}$ 및 Cr$^{3+}$ 등의 몇몇 중금속 이온들에 대해서도 약간의 흡착능을 보였다. 다른 한편으로, 친수성의 티오설폰산기 함유 III형 킬레이트 수지는 효율적 흡착체로서 Hg$^{2＋}$, Cu$^{2＋}$, Ni$^{2＋}$, Co$^{2＋}$ 및 Cr$^{3+}$ 등의 중금속 이온들은 물론, 특히 C$d^{2＋}$ 및 Pb$^{2＋}$에 높은 흡착능을 보였다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제13권10호
• /
• pp.1433-1439
• /
• 2000

An experiment was carried out with 48 IVRI 2CQ rats 6-8 week old, weighing 50-100 g, to study the effect of lead exposure on antioxidant defense, lipid peroxide level, status of thiol groups and concentration of lead in the liver and kidneys at the end of the exposure and also after withdrawal of lead administration. Twenty four rats were given lead at a daily dose rate of 1 mg lead/2 ml of distilled water/kg body weight as lead acetate solution intraperitoneally for a period of 30 days. Another 24 control rats received 2 ml of sterile normal saline solution (0.85% NaCl)/kg body weight in an identical manner. A many-fold increase in concentration of lead was associated with a non-significant (p>0.05) decrease in the activities of superoxide dismutase (SOD) in the liver (27%) and kidneys (12%) and catalase in kidneys (22%). A significant (p<0.05) increase in lipid peroxide level was recorded in the liver (40%) compared with control values. There were significant (p<0.05) decreases in the total thiol and protein bound thiol contents in liver and an increase in non-protein bound thiol groups in the kidneys of lead exposed rats. During the 10 day observation period after withdrawal of lead administration, no significant change was observed with respect to any of the above parameters indicating that a 10 day withdrawal period was not enough for restoration of normality. It is concluded that the magnitude of response and the resultant changes in the lipid peroxide concentration, and the activities of SOD and catalase were not identical in the liver and kidneys of lead-exposed rats.

• 한국환경보건학회지
• /
• 제11권2호
• /
• pp.65-75
• /
• 1985

Microorganisms capable of utilizing diaminododecane containing amine groups diterminally were isolated from the soil by enrichment culture. One strain of these isolated strain, designated as EL-0112L, was selected for this study. The results of this study were as follows. 1. This isolated strain EL-0112L was identified as Microbacterium, from the results of morphological, cultural, and biochemical tests. This isolated strain was named temporarily Microbacterium sp. EL-0112L for convenience. 2. Microbacterium sp. EL-0112L was tested for ability to utilize different kinds of substitued alkanes containing cyan, amine, chloro, and thiol groups(monoterminally or diterminall substituted) as carbon source. Pentamethylenediamine, hexamethylenediamine, n-decane, laurylamine, and alkane derivatives containing cyan, chloro, and thiol groups were not utilized by Microbacterium sp. EL-0112L. 3. The alkane derivatives that did not serve as growth substrates were tested further in oxidation tests using resting cell preparation of Microbacterium sp. EL-0112 L. Alkane derivatives containing cyan, chloro, thiol groups, and n-decane were oxidized by Microbacterium sp. EL-0112 L. It is possible that this isolated strain is also able to degrade their substituted counterparts since they are structually similar to diaminododecane. The remarkable substrates that were being oxidized were dichlorodecane, and 1-dodecanethiol. Microbacterium sp. EL- 0112L could not oxidize pentamethylenediamine, and hexamethylenediamine. 4. The metabolic products formed from diaminododecane by Microbacterium sp. EL-0112 L were acid compound containing carboxyl group and not containing amine group. On the thin layer chromatography, Rf values of these metabolic products were different from that of the product formed by Corynebacterium sp. EL-0112L. These results suggested the specificity of diaminododecane as carbon source.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
• /
• pp.197-197
• /
• 2011

In this study, in contrast with cases in which Scanning Tunneling Microscopy (STM) tip-induced reactions were instigated by the tunneling electrons, the local electric field, or the mechanical force between a tip and a surface, we found that the tungsten oxide (WO3) covered tungsten (W) tip of a STM acted as a chemical catalyst for the S-H dissociative adsorption of phenylthiol and 1-octanethiol onto a Ge(100) surface. By varying the distance between the tip and the surface, the degree of the tip-catalyzed adsorption could be controlled. We have found that the thiol head-group is the critical functional group for this catalysis and the catalytic material is the WO3 layer of the tip. After removing the WO3 layer by field emission treatment, the catalytic activity of the tip has been lost. 3-mercapto isobutyric acid is a chiral bi-functional molecule which has two functional groups, carboxylic acid group and thiol group, at each end. 3-Mercapto Isobutyric Acid adsorbs at Ge(100) surface only through carboxylic acid group at room temperature and this adsorption was enhanced by the tunneling electrons between a STM tip and the surface. Using this enhancement, it is possible to make thiol group-terminated surface where we desire. On the other hand, surprisingly, the WO3 covered W tip of STM was found to act as a chemical catalyst to catalyze the adsorption of 3-mercapto isobutyric acid through thiol group at Ge(100) surface. Using this catalysis, it is possible to make carboxylic acid group-terminated surface where we want. This functional group-selective adsorption of bi-functional molecule using the catalysis may be used in positive lithographic methods to produce semiconductor substrate which is terminated by desired functional groups.

• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• 제24권5호
• /
• pp.443-454
• /
• 2021

Purpose: Due to the increasing prevalence of obesity worldwide, non-alcoholic fatty liver disease (NAFLD) has reached epidemic dimensions over time. NAFLD is the most common cause of childhood chronic liver disease. There is a relationship between NAFLD and oxidative stress. This study aims to investigate the changes in thiol/disulfide homeostasis parameters to determine the oxidant/antioxidant balance in obese rats with diet-induced NAFLD and healthy rats. Methods: Twelve Wistar albino rats were used in this study. Experimentally produced NAFLD obese rats (n=6) and healthy rats were compared. Experimental NAFLD model was created with a special fatty liver diet (Altromin^® C1063, Fatty Liver Diet, Exclusivet, Lage, Germany). The biochemical and histopathological features of the groups, as well as serum thiol/disulfide homeostasis parameters, were analyzed and compared. Results: In the experimentally induced NAFLD rat model, they gained more weight than the control group. Steatosis (at least grade 2) occurred in all rats fed with special fatty liver diet for 12 weeks. Histopathologically, no high-grade inflammation was observed in rats with experimental NAFLD after feeding a diet for 12 weeks. Results revealed that aspartate transaminase and alanine transaminase levels were high, albumin levels were low, oxidant stress parameters increased, and antioxidant thiol groups decreased. Conclusion: Experimental NAFLD is characterized by increased oxidant stress accompanying fatty tissue in the liver. Analysis of thiol/disulfide homeostasis parameters in NAFLD can be used in further studies to develop effective treatment options.

• Applied Biological Chemistry
• /
• 제40권3호
• /
• pp.243-248
• /
• 1997

미나리 (O. javanica)는 오염된 하수 등에서도 매우 잘 자라는 식물체이다. 이런 미나리를 phytoremediation에 응용하기 위하여 $50\;{\mu}M$ 카드늄을 처리하여 카드늄에 대한 저항성 및 식물체에 축적된 카드늄을 정량하고 생리적, 생화학적 변화를 조사하였다. 카드늄을 처리하고 3주 뒤에 미나리는 거의 성장저해를 받지 않았으나 대조구로 사용한 담배 (N. tabacum Xanthi)는 75% 성장저해를 받았다. 미나리는 뿌리, 줄기, 잎에 건중량 1 그램당 각각 2.1, 7.3, $113\;{\mu}moles$의 카드늄을 축적하였다. 카드늄을 처리한 미나리의 경우 전체 thiol 잔기의 농도가 카드늄을 처리하지 않은 미나리에 비해 뿌리, 줄기, 잎에서 각각 0.5, 1,7배 증가하였으나 글루타치온 농도의 경우는 대조구에 비해 각각 57%, 30%, 53% 까지 감소하였다. 이를 HPLC로 조사해본 결과 증가된 thiol의 함량은 새로운 thiol 잔기를 지닌 물질의 생성으로 기인된 것이고, retention time을 기초로 이는 phytochelatin인 것으로 보여진다.

• 한국가축번식학회지
• /
• 제21권4호
• /
• pp.335-343
• /
• 1997

The effect of thiol compounds on development and intracellular glutathione(GSH) concentrations of bovine embryos produced by in vitro maturation and in vitro fertilization(IVM/IVF) was examined in CRlaa medium with or without $\beta$-mercaptoethanol(0, 10, 25 and 50$\mu$MME) and cysteamine(0, 25, 50 and 75 $\mu$M). Numbers of cells comprising blastocysts were also counted using double fluorescence stain and the total glutathione levels(oxidized and reduced form) of morula and blastocyst embryos were than measured by an enzymatic method. Following routine IVM/IVF procedures oocytes and zygotes were cultured for 40 to 44h in CRlaa medium. Then 2 to 8-cell embyos had cumulus cell removed and were allotted randomly to the experimental medium. In Experiment 1, the proportion of embryos developing to and beyond morulae stages in 0, 10, 25 and 50 $\mu$M $\beta$-ME was 42.9%, 50.0%, 53.7% and 65.6%, respectively. Fifty $\mu$M $\beta$-ME group was significantly higher than those of any other groups (P<0.05). In Experiment 2, the percentages of embryos developed beyond morulae stages in 0, 25, 50 and 75 $\mu$M cysteamine was 42.9%, 40.4%, 60.0% and 59.2%, respectively. Fifty and 75$\mu$M cysteamine groups were significantly higher than in 0 and 25 $\mu$M cysteamine groups, but all of culture medium containing cysteamine(52.6%) was not significantly difference in control group(42.9%). In Experiment 3, the intracellular GSH concentrations of morulae and blastocyst embryos in 0 and 50 $\mu$M $\beta$-ME was 42.4 pM and 44.9 pM, 49.5 pM and 67.8 pM, respectively. Morulae embryos were not difference, but blastocyst embryos were significantly difference between treatments(P<0.05). In Experiment 4, the intracellular GSH concentrations of morulae in CRlaa with or without cysteamine were 39.8 pM and 45.6 pM, and blastocysts were 59.3 pM and 66.8 pM, respectively. Cell numbers of blastocysts were similar to in all experimental groups. These experiments indicate that thiol compounds can increase the proportion of embryos that developing to and beyond morulae stage and the intracellular GSH concentrations.

• 폴리머
• /
• 제24권5호
• /
• pp.579-588
• /
• 2000

보호콜로이드에 따른 입체 안정제 (steric stabilizer)작용이 폴리초산비닐 (poly(vinyl acetate), PVAc) 라텍스의 안정성에 미치는 영향을 조사하였다. 보호콜로이드로서 중합도 1080, 검화도 78.4%인 반응성 poly(vinyl alcohol) mono thiol (PVALT)를 사용한 것이 중합도 1100, 검화도 81.6%인 poly(vinyl alcohol) (PVA)를 사용하는 것보다 PVAc 라텍스의 안정성이 양호하였으며, 반응성 PVALT의 첨가량이 증가할수록 PVAc 라텍스의 안정성은 향상되었다. PVAc 라텍스 입자의 표면 형태 변화는 투과전자 현미경으로 관찰하였다. 입자크기는 반응성 PVALT의 첨가량이 증가할수록 감소하였다. 결과적으로 에멀젼의 중합 시 PVA보다 반응성 PVALT를 사용하는 것이 PVAc 라텍스의 안정성이 양호함을 알 수 있었다. 이는 반응성 PVALT로 인해 PVAc 라텍스 입자계면에 PVA와의 화학 결합을 유도할 수 있는 다량의 티올 (thiol)기가 도입되어 PVAc와 반응성 PVALT간의 화학반응으로 인한 PVALT-b-PVAc 블록 공중합체가 생성됨에 기인하는 것으로 사료된다. 아울러 제타전위는 탄산나트륨의 농도가 증가할수록 감소하였다.

• 대한의생명과학회지
• /
• 제10권1호
• /
• pp.43-48
• /
• 2004

Changes of thiol methyltransferase (TMT) activity in cholestatic rat liver were studied. Hepatic subcellular and serum TMT activities were determined in cholestatic rat induced by common bile duct (CBD) ligation over a period 28 days. The mitochondrial and microsomal TMT activities in cholestatic rat liver were found to be significantly increased between the 1st and the 28th day after CBD ligation. The TMT activity in serum was significantly increased throughout the experiments. The Vmax values of the above hepatic TMT in cholestatic rat were significantly increased at the 7th day after CBD ligation. However, the Km values of the above hepatic enzymes did not vary in all the experimental groups. Therefore, the results indicate that the biosynthesis of TMT was increased in cholestatic rat liver. The elevated serum TMT activity is most likely caused by increased hepatocytes membrane permeability due to cholestasis mediated liver cell necrosis.