• Journal of Microbiology and Biotechnology
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• v.30 no.8
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• pp.1261-1271
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• 2020

Cytochrome c_L (Cytc_L) is an essential protein in the process of methanol oxidation in methylotrophs. It receives an electron from the pyrroloquinoline quinone (PQQ) cofactor of methanol dehydrogenase (MDH) to produce formaldehyde. The direct electron transfer mechanism between Cytc_L and MDH remains unknown due to the lack of structural information. To help gain a better understanding of the mechanism, we determined the first crystal structure of heme c containing Cytc_L from the aquatic methylotrophic bacterium Methylophaga aminisulfidivorans MP^T at 2.13 Å resolution. The crystal structure of Ma-Cytc_L revealed its unique features compared to those of the terrestrial homologues. Apart from Fe in heme, three additional metal ion binding sites for Na⁺, Ca⁺, and Fe²⁺ were found, wherein the ions mostly formed coordination bonds with the amino acid residues on the loop (G93-Y111) that interacts with heme. Therefore, these ions seemed to enhance the stability of heme insertion by increasing the loop's steadiness. The basic N-terminal end, together with helix α4 and loop (G126 to Y136), contributed positive charge to the region. In contrast, the acidic C-terminal end provided a negatively charged surface, yielding several electrostatic contact points with partner proteins for electron transfer. These exceptional features of Ma-Cytc_L, along with the structural information of MDH, led us to hypothesize the need for an adapter protein bridging MDH to Cytc_L within appropriate proximity for electron transfer. With this knowledge in mind, the methanol oxidation complex reconstitution in vitro could be utilized to produce metabolic intermediates at the industry level.

• Korean Journal of Acupuncture
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• v.29 no.1
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• pp.37-46
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• 2012

Objectives : The gnarl of Pinus densiflora, called Songjeol in Korea, has been used as a medicinal herb for the treatment of inflammatory-related diseases such as arthralgia, myalgia and bruise. However, the molecular actions and mechanisms have not been clearly investigated. The aim of this study was to clarify the anti-inflammatory activity of Pinus densiflora gnarl pharmacopuncture (PDGP) in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Methods : Cytotoxicity was assessed by XTT assay. The amount of nitric oxide (NO) production was determined by nitrite assay. The mRNA expressions of interleukin-$1{\beta}$ (IL-$1{\beta}$), interleukin-6 (IL-6), cyclooxygenase-2 (COX-2) and heme oxygenase-1 (HO-1) were analyzed by RT-PCR. Reactive oxidative species (ROS) generation was measured using the fluorescence microscopy. In addition, inducible nitric oxide synthase (iNOS) and redox factor-1 (Ref-1) protein expressions were detected by Western blotting. Results : PDGP inhibited NO production and ROS generation in LPS-stimulated RAW264.7 cells. At the mRNA level, PDGP suppressed IL-$1{\beta}$, IL-6 and COX-2 expression. On the other hand, PDGP induced HO-1 mRNA expression. Furthermore, PDGP suppressed iNOS and Ref-1 protein expression. Conclusions : This result suggests that PDGP can act as a suppressor agent on NO and iNOS through induction of HO-1, and play an useful role in blocking inflammatory responses.

• Environmental Mutagens and Carcinogens
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• v.26 no.4
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• pp.97-112
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• 2006

Heme oxygenase(HO)-1 is an important antioxidant enzyme that plays a pivotal role in cellular adaptation and protection in response to a wide array of noxious stimuli. Thus, HO-1 induction has been associated with prevention or mitigation of pathogenesis of various diseases, including acute inflammation, atherosclerosis, degenerative diseases, and carcinogenesis. Recent progress in our understanding of the function of molecules in the cellular signaling network as key modulators of gene transcription sheds light on the molecular mechanisms underlyuing HO-1 gene expression. A panel of redox-sensitive transcription factors such as activator protein-1, nuclear factor-kB, and nuclear factor E2-related factor-2, and some of the upstream kinases have been identified as prime regulators of HO-1 gene induction. This review summarizes molecular mechanisms underlying HO-1 expression and the significance of targeted induction of HO-1 as a potential chemopreventive or chemoprotective strategy.

• Journal of Plant Biology
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• v.36 no.3
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• pp.301-304
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• 1993

Root nodule specific proteins of Alnus hirsuta were examined. SDS-PAGE pattern of the Alnus root nodule was simpler than that of soybean, showing five nodule specific proteins whose molecular weights were 48, 40, 36, 26 and 19 kD, respectively. Among them, 48 kD protein existed most abundantly and were composed of two subunits whose pI value were 4.0 and 4.3, respectively. The 48 kD protein seemed to be a heme containing protein based on reaction with diaminobenzidine. Although 19 kD protein was present in small amount, it was most similar to leghemoglobin in terms of its molecular weight.

• BMB Reports
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• v.31 no.2
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• pp.161-169
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• 1998

TThe reactive oxygen species oxidatively modify the biological macromolecules, including proteins, lipids, and nucleic acids. Iron- and heme-mediated Fenton-like reactions produce different pro-oxidants. However, these reactive products have not been clearly characterized. We examined the nature of the oxidizing species from the different iron sources by measuring oxidative protein modification and spectroscopic study. Hemoglobin (Hb) and methemoglobin (metHb) were oxidatively modified in $O{\array-\\\dot{2}}$ and $H_{2}O_{2}$ generating systems. Globin and bovine serum albumin (BSA) were also modified by iron, iron-EDTA, hematin, and Hb in an $O{\array-\\\dot{2}}$ generating system. In a $H_{2}O_{2}$ generating system, the iron- and iron-EDTA-mediated protein modifications were markedly reduced while the Hb-and hematin-mediated modifications were slightly increased. In the $O{\array-\\\dot{2}}$ generating system, the iron- and iron-EDTA-mediated protein modifications were strongly inhibited by superoxide dismutase (SOD) or catalase, but heme- and Hb-mediated protein modifications were inhibited only by catalase and slightly increased by SOD. Mannitol, 5,5-dimethyl-l-pyrroline-N-oxide (DMPO), deoxyribose, and thiourea inhibited the iron-EDTA-mediated protein modification. Mannitol and DMPO, however, did not exhibit significant inhibition in the hematin-mediated modification. Desferrioxamine (DFO) inhibited protein modification mediated by iron, but cyanide and azide did not, while the hematin-mediated protein modification was inhibited by cyanide and azide, but not significantly by DFO. The protein-modified products by iron and heme were different. ESR and UV-visible spectroscopy detected the DMPO spin adduct of the hydroxyl radical and ferryl ion generated from iron-EDTA and metHb, respectively. These results led us to conclude that the main oxidizing species are hydroxyl radical in the iron-EDTA type and the ferry I ion in the hematin type, the latter being more effective for protein modification.

• KSBB Journal
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• v.20 no.1 s.90
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• pp.21-25
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• 2005

Paraquat, a widely used herbicide, has been suggested as a potential risk factor for Parkinson's disease. Heme oxygenase-1(HO-1), a marker for oxidative stress and endoplasmic reticulum(ER) stress, is known to catalyze heme to biliverdin, carbon monoxide and free iron in response to various stimuli. Here we show that paraquat activates HO-1 expression in a time-and dose-dependent manner in substantia nigra(SN) dopaminergic neuronal cells. Activation of Ho-1 by paraquat was regulated primarily at the level of gene transcription. Deletion analysis of the promoter and the 5' distal enhancers, E1 and E2, of the HO-1 gene revealed that the E2 enhancer is a potent inducer of the paraquat-dependent Ho-1 gene expression in dopamninergic neuronal cells. Mutational analysis of the E2 enhacer further demonstrated that the transcription factor activator protein-1(AP-1) plays an important role in mediating paraquat-induced HO-1 gene transcription. Moreover, using specific inhibitors of the mitogen-activated protein kinases(MAPKs), we investigated the role of paraquat and MAPKs for HO-1 gene regulation in dopaminergic cells. The c-Jun N-terminal kinase(JNK) inhibitor SP600125 significantly suppressed the expression of HO-1 by paraquat. All these results demonstrate that induction of HO-1 by paraquat requies the activation of the AP-1 and JNK pathway.

• Food Science of Animal Resources
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• v.37 no.2
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• pp.228-241
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• 2017

Hematological, chemical and functional characteristics of porcine, chicken and duck blood were evaluated. A porcine blood sample showed the most abundant red blood cell, hemoglobin concentration, packed cell volume and plasma protein content as well as its freeze-dried blood possessed the highest contents of protein, fat, Cu and Cr with the highest percentage of heme iron (p<0.05). Unlike porcine blood, chicken blood showed a well balance in some essential amino acids, specifically for a higher isoleucine content (p<0.05). Furthermore, it possessed the highest contents of carbohydrate, Zn and non-heme iron (p<0.05). The most rapid response to form a strong gel, especially at $70^{\circ}C$ and $80^{\circ}C$, was found in chicken blood, followed by duck and porcine blood, respectively. The result of emulsion activity index (EAI) and emulsion stability index (ESI) at the low protein concentration indicated that chicken blood had the most superior emulsion properties (p<0.05). Regarding duck blood, it exhibited the highest content of Mg and Mn (p<0.05). Moreover, duck blood had similar foaming properties to porcine blood in which they showed higher values than chicken blood (p<0.05). Specific characteristics of blood were therefore diminished by animal species in which this information could be used as food supplementation or product development based on their potential applications.

• Journal of Nutrition and Health
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• v.30 no.2
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• pp.147-154
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• 1997

This study was conducted to evaluate dietary fiber intake, iron status, and their correlations in 50 female college students living in Seoul. The nutritional status was analyzed using 3-day dietary record, duplicated diet collection, and venous blood sampling. The mean values for age, height, weight, BMI, and blood pressure of the subjects were 23.2 years, 160.2cm, 53.9kg, 21.0kg/$m^2$, and 110.1/68.4mmHg, respectively. Daily intakes of enery, protein, fiber, crude fiber, iron, and heme iron were 1635.5㎉, 54.3g, 22.5g, 6.8g, 16.2mg, and 0.2mg, respectively. Fiver intake was positively correlate with energy, protein, carbohydrate, vitamin C, iron, and crude fiber intakes. Also, iron intake was positively correlated with energy, protein, lipid, carbohydrate, and vitamin C intakes. There was a significant correlation between heme iron and MFP(meat, fish, poultry) intakes. To exame the iron balance, iron intake and excretion were measured. Iron intake and excretions through urine and feces were 19.5mg, 8.5mg, and 1.6mg, respectively. Based on these iron retention and iron apparent absorbability were calculated as 9.4mg and 52.4%, respectively. There was no significant relationship between dietary fiber intake and iron status. However, there were significant positive correlation between fiber intake and urinary iron excretion.

• BMB Reports
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• v.34 no.4
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• pp.385-389
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• 2001

Insulin-like growth factor binding protein-1 (IGFBP-1) appears to be an important modular of the insulin growth factor (IGF) bioactivity in metabolic disease and chronic hypoxia. Treatment of desferrioxamine (Dfo), cobalt, or nickel in HepG2 cells stimulated the expression of IGFBP1 mRNA as hypoxia. However, the presence of ferric ammonium citrate (FAC) in the 1% $O_2$ decreased the upregulation of the IGFBP-1 mRNA expression. In addition, actinomycin D and cycloheximide abolished the increase in the expression of IGFBP-1 mRNA that was induced by Dfo and transition metals (cobalt and nickel). To obtain further information about the putative oxygen sensor, we postulate that putative heme proteins, responsible for the oxygen-sensing process in HepG2 cells, should be sensitive to hypoada. The mechanism of these upregulations of the IGFBP-1 mRNA expression by Dfo and transition metals was investigated by treatment with 2 mM of 4,6-dioxoheptanoic acid (DHA), an inhibitor of heme biosynthesis. The results showed that 1% $O_2$-, Dfo-, cobalt-, or nickel induced IGFBP-1 mRNA expressions in HepG2 cells were all markedly inhibited when the heme synthesis was blocked by DHA. We suggest that the IGFBP-1 mRNA expression in the HepG2 cell is regulated by 1% $O_2$, Dfo, cobalt, or nickel, implicating the involvement of the putative heme-containing oxygensensing molecule.

• Journal of Life Science
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• v.13 no.6
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• pp.814-821
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• 2003

Protoporphyrin IX is an intermediate molecule in the heme biosynthetic pathway. Intra- and extracellular concentrations of protoporphyrin IX in the wild type strain, Myxococcus xanthus DK1622 were measured by reverse phase HPLC. The amount of intracellular protoporphyrin IX continuously increased and reached 6.4 picomoles/mg of protein at the stationary phase. Extracellular protoporphyrin IX began to be detected from the mid-exponential phase. The culture supernatant that was collected in the stationary phase contained approximately 3.0 picomoles of proto-porphyrin IX per mg of protein. Spores formed by nutrient depletion contained about 6.5 picomole protoporphyrin IX/mg of protein. The synthesis of protoporphyrin IX and cell growth were strongly inhibited by addition of succinylacetone to a final concentration of $500\muM$. Succinylacetone, however did not appear to interfere developmental processes. Normal developmental behaviors including aggregation and spore formation was achieved even if succinylacetone was added in a medium. Photolysis among cells grown on a starvation medium supplemented with succinylacetone was also observed. These results indicate that protoporphyrin IX may be important to M. ,xanthus vegetative growth, but not critical to development processes.