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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Korean Society for Biochemistry and Molecular Biology
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Volume & Issues
Volume 38, Issue 6 - Nov 2005
Volume 38, Issue 5 - Sep 2005
Volume 38, Issue 4 - Jul 2005
Volume 38, Issue 3 - May 2005
Volume 38, Issue 2 - Mar 2005
Volume 38, Issue 1 - Jan 2005
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Overview of Innate Immunity in Drosophila
Kim, Tae-Il ; Kim, Young-Joon ;
BMB Reports , volume 38, issue 2, 2005, Pages 121~127
DOI : 10.5483/BMBRep.2005.38.2.121
Drosophila protects itself from infection by microbial organisms by means of its pivotal defense, the so-called innate immunity system. This is its sole defense as it lacks an adaptive immunity system such as is found in mammals. The strong conservation of innate immunity systems in organisms from Drosophila to mammals, and the ease with which Drosophila can be manipulated genetically, makes this fly a good model system for investigating the mechanisms of virulence of a number of medically important pathogens. Potentially damaging endogenous and/or exogenous challenges sensed by specific receptors initiate signals via the Toll and/or Imd signaling pathways. These in turn activate the transcription factors Dorsal, Dorsal-related immune factor (Dif) and Relish, culminating in transcription of genes involved in the production of antimicrobial peptides, melanization, phagocytosis, and the cytoskeletal rearrangement required for appropriate responses. Clarifying the regulatory interactions between the various pathways involved is very important for understanding the specificity and termination mechanism of the immune response.
Recent Advances in the Innate Immunity of Invertebrate Animals
Iwanaga, Sadaaki ; Lee, Bok-Luel ;
BMB Reports , volume 38, issue 2, 2005, Pages 128~150
DOI : 10.5483/BMBRep.2005.38.2.128
Invertebrate animals, which lack adaptive immune systems, have developed other systems of biological host defense, so called innate immunity, that respond to common antigens on the cell surfaces of potential pathogens. During the past two decades, the molecular structures and functions of various defense components that participated in innate immune systems have been established in Arthropoda, such as, insects, the horseshoe crab, freshwater crayfish, and the protochordata ascidian. These defense molecules include phenoloxidases, clotting factors, complement factors, lectins, protease inhibitors, antimicrobial peptides, Toll receptors, and other humoral factors found mainly in hemolymph plasma and hemocytes. These components, which together compose the innate immune system, defend invertebrate from invading bacterial, fungal, and viral pathogens. This review describes the present status of our knowledge concerning such defensive molecules in invertebrates.
Gene Expression Profiles of HeLa Cells Impacted by Hepatitis C Virus Non-structural Protein NS4B
Zheng, Yi ; Ye, Lin-Bai ; Liu, Jing ; Jing, Wei ; Timani, Khalid A. ; Yang, Xiao-Jun ; Yang, Fan ; Wang, Wei ; Gao, Bo ; Wu, Zhen-Hui ;
BMB Reports , volume 38, issue 2, 2005, Pages 151~160
DOI : 10.5483/BMBRep.2005.38.2.151
By a cDNA array representing 2308 signal transduction related genes, we studied the expression profiles of HeLa cells stably transfected by Hepatitis C virus nonstructural protein 4B (HCV-NS4B). The alterations of the expression of four genes were confirmed by real-time quantitative RT-PCR; and the aldo-keto reductase family 1, member C1 (AKR1C1) enzyme activity was detected in HCV-NS4B transiently transfected HeLa cells and Huh-7, a human hepatoma cell line. Of the 2,308 genes we examined, 34 were up-regulated and 56 were down-regulated. These 90 genes involved oncogenes, tumor suppressors, cell receptors, complements, adhesions, transcription and translation, cytoskeletion and cellular stress. The expression profiling suggested that multiple regulatory pathways were affected by HCV-NS4B directly or indirectly. And since these genes are related to carcinogenesis, host defense system and cell homeostatic mechanism, we can conclude that HCV-NS4B could play some important roles in the pathogenesis mechanism of HCV.
Cloning and Characterization of a Gene Encoding 22 kDa Functional Protein of Bacteriophage MB78
Gupta, Lalita ; Chakravorty, Maharani ;
BMB Reports , volume 38, issue 2, 2005, Pages 161~166
DOI : 10.5483/BMBRep.2005.38.2.161
Functional protein of MB78 bacteriophage having apparent molecular weight of 22 kDa is expressed from 1.7 kb HindIII G fragment. The nucleotide sequence of this fragment showed two open reading frames of 222 and 196 codons in tail-to-tail orientation separated by a 62-nucleotide intercistronic region. The ORF of 22 kDa protein is present in opposite orientation, i.e. in the complementary strand, preceded by a strong ribosomal binding site and a promoter sequence. Another ORF started from the beginning of the fragment whose promoter region and translational start site lies in the 0.45 kb HincII U fragment which is located next to the HindIII G fragment, that has the sequence for DNA bending. 3' end of the fragment has high sequence homology to the EaA and EaI proteins of bacteriophage P22, a close relative of MB78 phage.
Differential Expression and Stability of Endogenous Nuclear Factor E2-related Factor 2 (Nrf2) by Natural Chemopreventive Compounds in HepG2 Human Hepatoma Cells
Jeong, Woo-Sik ; Keum, Young-Sam ; Chen, Chi ; Jain, Mohit R. ; Shen, Guoxiang ; Kim, Jung-Hwan ; Li, Wenge ; Kong, Ah-Ng Tony ;
BMB Reports , volume 38, issue 2, 2005, Pages 167~176
DOI : 10.5483/BMBRep.2005.38.2.167
Nuclear factor-E2-related factor 2 (Nrf2) is known as a key regulator of ARE-mediated gene expression and the induction of Phase II detoxifying enzymes and antioxidant enzymes, which is also a common property of many chemopreventive agents. In the present study, we investigated the regulatory role of different chemopreventive agents including sulforaphane (SUL), allyl isothiocyanate (AITC), indole-3-carbinol (I3C), and parthenolide (PTL), in the expression and degradation of Nrf2 and the induction of the antioxidant enzyme HO-1. SUL strongly induced Nrf2 protein expression and ARE-mediated transcription activation, retarded degradation of Nrf2 through inhibiting Keap1, and thereby activating the transcriptional expression of HO-1. AITC was also a potent inducer of Nrf2 protein expression, ARE-reporter gene and HO-1 but had little effect on delaying the degradation of Nrf2 protein. Although PTL and I3C could induce ARE reporter gene expression and Nrf2 to some extent, they were not as potent as SUL and AITC. However, PTL dramatically induced the HO-1 expression, which was comparable to SUL, while I3C had no effect. In addition, when treated with SUL and PTL, inhibition of proteasome by MG132 did not cause additional accumulation of Nrf2, suggesting the involvement of other degradation mechanism(s) in the presence of these compounds such as SUL and PTL. In summary, the results of our current study indicated that different chemopreventive compounds have different regulatory properties on the accumulation and degradation of Nrf2 as well as the induction of cellular antioxidant enzyme HO-1.
Comparative Study of Enzyme Activity and Stability of Bovine and Human Plasmins in Electrophoretic Reagents, β-mercaptoethanol, DTT, SDS, Triton X-100, and Urea
Choi, Nack-Shick ; Hahm, Jeung-Ho ; Maeng, Pil-Jae ; Kim, Seung-Ho ;
BMB Reports , volume 38, issue 2, 2005, Pages 177~181
DOI : 10.5483/BMBRep.2005.38.2.177
Effects of common electrophoretic reagents, reducing agents (
-mercaptoethanol [BME] and DTT), denaturants (SDS and urea), and non-ionic detergent (Triton X-100), on the activity and stability of bovine plasmin (b-pln) and human plasmin (h-pln) were compared. In the presence of 0.1% SDS (w/v), all reagents completely inhibited two plns, whereas SDS (1%) and urea (1 M) denatured plns recovered their activities after removal of SDS by treatment of 2.5% Triton X-100 (v/v). However, reducing agents (0.1 M of BME and DTT) treated plns did not restore their activities. Based on a fibrin zymogram gel, five (from b-pln) and four (from h-pln) active fragments were resolved. Two plns exhibited unusual stability in concentrated SDS and Triton X-100 (final 10%) and urea (final 6 M) solutions. Two bands, heavy chain-2 (HC-2) and cleaved heavy chain-2 (CHC-2), of b-pln were completely inhibited in 0.5% SDS or 3 M urea, whereas no significant difference was found in h-pln. Interestingly, 50 kDa (cleaved heavy chain-1, CHC-1) of b-pln and two fragments, 26 kDa (light chain, LC) and 29 kDa (microplasmin, MP), of h-pln were increased by SDS in a concentration dependent manner. We also found that the inhibition of SDS against both plns was reversible.
Genetic Heterogeneity of the Tropical Abalone (Haliotis asinina) Revealed by RAPD and Microsatellite Analyses
Tang, Sureerat ; Popongviwat, Aporn ; Klinbunga, Sirawut ; Tassanakajon, Anchalee ; Jarayabhand, Padermsak ; Menasveta, Piamsak ;
BMB Reports , volume 38, issue 2, 2005, Pages 182~190
DOI : 10.5483/BMBRep.2005.38.2.182
Genetic heterogeneity of the tropical abalone, Haliotis asinina was examined using randomly amplified polymorphic DNA (RAPD) and microsatellite analyses. One hundred and thirteen polymorphic RAPD fragments were generated. The percentage of polymorphic bands of H. asinina across overall primers was 85.20%. The average genetic distance of natural samples within the Gulf of Thailand (HACAME and HASAME) was 0.0219. Larger distance was observed when those samples were compare with HATRAW from the Andaman Sea (0.2309 and 0.2314). Geographic heterogeneity and
analyses revealed population differentiation between H. asinina from the Gulf of Thailand and the Andaman Sea (p < 0.0001). Three microsatellite loci (CUHas1, CUHas4 and CUHas5) indicated relatively high genetic diversity in H. asinina (total number of alleles = 26, 5, 23 and observed heterozygosity = 0.84, 0.42 and 0.33, respectively). Significant population differentiation was also found between samples from different coastal regions (p < 0.0001). Therefore, the gene pool of natural H. asinina in coastal Thai waters can be genetically divided to 2 different populations; the Gulf of Thailand (A) and the Andaman Sea (B).
A Modified Mutation Detection Method for Large-scale Cloning of the Possible Single Nucleotide Polymorphism Sequences
Jiang, Ming-Chung ; Jiang, Pao-Chu ; Liao, Ching-Fong ; Lee, Ching-Chiu ;
BMB Reports , volume 38, issue 2, 2005, Pages 191~197
DOI : 10.5483/BMBRep.2005.38.2.191
Although the human genome has been nearly completely sequenced, the functions and the roles of the vast majority of the genes, and the influences of single nucleotide polymorphisms (SNPs) in these genes are not entirely known. A modified mutation detection method was developed for large-scale cloning of the possible SNPs between tumor and normal cells for facilitating the identification of genetic factors that associated with cancer formation and progression. The method involves hybridization of restriction enzyme-cut chromosomal DNA, cleavage and modification of the sites of differences by enzymes, and differential cloning of sequence variations with a designed vector. Experimental validations of the presence and location of sequence variations in the isolated clones by PCR and DNA sequencing support the capability of this method in identifying sequence differences between tumor cells and normal cells.
Interaction of Resveratrol and Genistein with Nucleic Acids
Usha, Subbiah ; Johnson, Irudayam Maria ; Malathi, Raghunathan ;
BMB Reports , volume 38, issue 2, 2005, Pages 198~205
DOI : 10.5483/BMBRep.2005.38.2.198
Resveratrol (RES) and genistein (GEN) are the dietary natural products known to possess chemopreventive property and also the ability to repair DNA damage induced by mutagens/carcinogens. It is believed that the therapeutic activity of these compounds could be primarily due to their interaction with nucleic acids but detailed reports are not available. We here explore the interaction of these drugs with nucleic acids considering DNA and RNA as a potential therapeutic target. The interaction of RES and GEN has been analysed in buffered solution with DNA [saline sodium citrate (SSC)] and RNA [tris ethylene diammine tetra acetic acid (TE)] using UV-absorption and Fourier transform infrared (FTIR) spectroscopy. The UV analysis revealed lesser binding affinity with nucleic acids at lower concentration of RES (P/D = 5.00 and 10.00), while at higher drug concentration (P/D = 0.75, 1.00 and 2.50) hyperchromic effect with shift in the
is noted for DNA and RNA. A major RES-nucleic acids complexes was observed through base pairs and phosphate backbone groups with K =
and K =
for DNA-RES and RNA-RES complexes respectively. At various concentrations of GEN (P/D = 0.25, 0.50, 0.75, 1.00 and 2.50) hyperchromicity with shift in the
263 om and 260
270 nm is observed for DNA-GEN and RNA-GEN complexes respectively. The binding constant (from UV analysis) for GEN-nucleic acids complexes could not be obtained due to GEN absorbance overlap with that of nucleic acids at 260 nm. Nevertheless a detailed analysis with regard to the interaction of these drugs (RES/GEN) with DNA and RNA could feasibly be understood by FTIR spectroscopy. The NH band of free DNA and RNA which appeared at
in DNA-RES and RNA-RES complexes respectively. Similarly shifts corresponding to
have been observed in DNA-GEN and RNA-GEN complexes respectively. The observed reduction in NH band of free nucleic acids upon complexation of these drugs is an indication of the involvement of the hydroxyl (OH) and imino (NH) group during the interaction of the drugs and nucleic acids (DNA/RNA) through H-bonded formation. The interaction of RES and GEN with bases appears in the order of G
T > C > A and A > C
T > G. Further interaction of these natural compounds with DNA and RNA is also supported by changes in the vibrational frequency (shift/intensity) in symmetrical and asymmetrical stretching of aromatic rings of drugs in the complex spectra. No appreciable shift is observed in the DNA and RNA marker bands, indicating that the B-DNA form and A-family conformation of RNA are not altered during their interaction with RES and GEN.
Cloning and Expression Analysis of Gonadogenesis-associated Gene SPATA4 from Rainbow Trout (Oncorhynchus mykiss)
Liu, Bowen ; Liu, Shangfeng ; He, Shan ; Zhao, Ying ; Hu, Hongxia ; Wang, Zhao ;
BMB Reports , volume 38, issue 2, 2005, Pages 206~210
DOI : 10.5483/BMBRep.2005.38.2.206
Gonadogenesis is a complicated process which involves multi-gene interactions. A rainbow trout (Oncorhynchus mykiss) gene spermatogenesis associated 4 (SPATA4) was cloned and characterized from adult rainbow trout testis. The cDNA sequence of rainbow trout SPATA4 contains an open reading frame of 1, 081 nucleatides encoding a putative protein of 259 amino acids. The putative protein from rainbow trout shares a 76.8% homology with zebrafish SPATA4. No trans-membrane regions or signal peptide were detected using bioinformatics methods. Subcellular localization analysis revealed that rainbow trout SPATA4 was a nuclear protein with highest possibility (39.1%). Multi-tissue reverse transcriptase PCR (RT-PCR) was performed to examine the distribution of rainbow trout SPATA4 in eleven organs of adult rainbow trout. The result demonstrated that this gene express specifically in testis and slight amount of expression was detected in ovary. Further analysis of SPATA4 characterization and function in rainbow trout may provide insight into the understanding of gonadogenesis process.
4-Acetoxyscirpendiol of Paecilomyces tenuipes Inhibits Na
/D-Glucose Cotransporter Expressed in Xenopus laevis Oocytes
Yoo, Oc-Ki ; Son, Joo-Hiuk ; Lee, Dong-Hee ;
BMB Reports , volume 38, issue 2, 2005, Pages 211~217
DOI : 10.5483/BMBRep.2005.38.2.211
Cordyceps, an entomopathogenic fungus, contains many health-promoting ingredients. Recent reports indicate that the consumption of cordyceps helps reduce blood-sugar content in diabetics. However, the mechanism underlying this reduction in circulatory sugar content is not fully understood. Methanolic extracts were prepared from the fruiting bodies of Paecilomyces tenuipes, and 4-beta acetoxyscirpendiol (4-ASD) was eventually isolated and purified.
/Glucose transporter-1 (SGLT-1) was expressed in Xenopus oocytes, and the effect of 4-ASD on SGLT-1 was analyzed utilizing a voltage clamp and by performing 2-deoxy-D-glucose (2-DOG) uptake studies. 4-ASD was shown to significantly inhibit SGLT-1 activity compared to the non-treated control in a dose-dependent manner. In the presence of the derivatives of 4-ASD (diacetoxyscirpenol or 15-acetoxyscirpendiol), SGLT-1 activity was greatly inhibited in an 4-ASD-like manner. Of these derivatives, 15-acetoxyscirepenol inhibited SGLT-1 as well as 4-ASD, whereas diacetoxyscirpenol was slightly less effective. Taken together, these results strongly indicate that 4-ASD in P. tenuipes may lower blood sugar levels in the circulatory system. We conclude that 4-ASD and its derivatives are effective SGLT-1 inhibitors.
Enhanced Antioxidant Enzymes Are Associated with Reduced Hydrogen Peroxide in Barley Roots under Saline Stress
Kim, Sang-Yong ; Lim, Jung-Hyun ; Park, Myoung-Ryoul ; Kim, Young-Jin ; Park, Tae-Il ; Seo, Yong-Won ; Choi, Kyeong-Gu ; Yun, Song-Joong ;
BMB Reports , volume 38, issue 2, 2005, Pages 218~224
DOI : 10.5483/BMBRep.2005.38.2.218
Antioxidant enzymes are related to the resistance to various abiotic stresses including salinity. Barley is relatively tolerant to saline stress among crop plants, but little information is available on barley antioxidant enzymes under salinity stress. We investigated temporal and spatial responses of activities and isoform profiles of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), non-specific peroxidase (POX), and glutathione reductase (GR) to saline stress in barley seedlings treated with 200 mM NaCl for 0, 1, 2, 5 days, respectively. In the control plant, hydrogen peroxide content was about 2-fold higher in the root than in the shoot. Under saline stress, hydrogen peroxide content was decreased drastically by 70% at 2 d after NaCl treatment (DAT) in the root. In the leaf, however, the content was remained unchanged by 2 DAT and increased about 14 % at 5 DAT. In general, the activities of antioxidant enzymes were increased in the root and shoot under saline stress. But the increase was more significant and consistent in the root. The activities of SOD, CAT, APX, POX, and GR were increased significantly in the root within 1 DAT, and various elevated levels were maintained by 5 DAT. Among the antioxidant enzymes, CAT activity was increased the most drastically. The significant increase in the activities of SOD, CAT, APX, POX, and GR in the NaCl-stressed barley root was highly correlated with the increased expression of the constitutive isoforms as well as the induced ones. The hydrogen peroxide content in the root was most highly correlated with the CAT activity, indicating an increased role of CAT in hydrogen peroxide detoxification under salinity stress. In addition, the results suggest the significance of temporal and spatial regulation of each antioxidant isoform in determining the competence of the antioxidant capacity under saline stress.
Expression of Porcine Acid-labile Subunit (pALS) of the 150-kilodalton Ternary Insulin-like Growth Factor Complex and Initial Characterization of Recombinant pALS Protein
Lee, Dong-Hee ; Chun, Choa ; Kim, Sang-Hoon ; Lee, C.-Young ;
BMB Reports , volume 38, issue 2, 2005, Pages 225~231
DOI : 10.5483/BMBRep.2005.38.2.225
Acid-labile subunit (ALS) is a component of the 150-kDa insulin-like growth factor-binding protein-3 (IGFBP-3) complex, which, by sequestering the majority of IGFs-I and -II and thereby prolonging the half-life of them in plasma, serves as a circulating reservoir of IGFs in mammalian species. A pGEX-2T plasmid and a baculovirus expression constructs harboring a coding sequence for glutathione-S transferase (GST)-porcine ALS (pALS) fusion protein were expressed in BL21(DE3) E. coli and Sf9 insect cells, respectively. The expressed protein was purified by glutathione or Ni-NTN affinity chromatography, followed by cleavage of the fusion protein using Factor Xa. In addition, pALS and hIGFBP-3 were also produced in small amounts in the Xenopus oocyte expression system which does not require any purification procedure. A 65-kDa pALS polypeptide was obtained following the prokaryotic expression and the enzymatic digestion, but biochemical characterization of this polypeptide was precluded because of an extremely low expression efficiency. The baculovirus-as well as Xenopus-expressed pALS exhibited the expected molecular mass of 85 kDa which was reduced into 75 and 65 kDa following deglycosylation of Asn-linked carbohydrates by Endo-F glycosidase, indicating that the expressed pALS was properly glycosylated. Moreover, irrespective of the source of pALS, the recombinant pALS and hIGFBP-3 formed a 130-kDa binary complex which could be immunoprecipitated by anti-hIGFBP-3 antibodies. Collectively, results indicate that an authentic pALS protein can be produced by the current expression systems.
Purification and Biochemical Properties of Glutathione S-Transferase from Lactuca sativa
Park, Hee-Joong ; Cho, Hyun-Young ; Kong, Kwang-Hoon ;
BMB Reports , volume 38, issue 2, 2005, Pages 232~237
DOI : 10.5483/BMBRep.2005.38.2.232
A glutathione S-transferase (GST) from Lactuca sativa was purified to electrophoretic homogeneity approximately 403-fold with a 9.6% activity yield by DEAE-Sephacel and glutathione (GSH)-Sepharose column chromatography. The molecular weight of the enzyme was determined to be approximately 23,000 by SDS-polyacrylamide gel electrophoresis and 48,000 by gel chromatography, indicating a homodimeric structure. The activity of the enzyme was significantly inhibited by S-hexylGSH and S-(2,4-dinitrophenyl) glutathione. The enzyme displayed activity towards 1-chloro-2,4-dinitrobenzene, a general GST substrate and high activities towards ethacrynic acid. It also exhibited glutathione peroxidase activity toward cumene hydroperoxide.
The Association between the T102C Polymorphism of the HTR2A Serotonin Receptor Gene and HDL Cholesterol Level in Koreans
Choi, Jin-Ho ; Zhang, Shu-Ying ; Park, Kyung-Woo ; Cho, Young-Seok ; Oh, Byung-Hee ; Lee, Myoung-Mook ; Park, Young-Bae ; Kim, Hyo-Soo ;
BMB Reports , volume 38, issue 2, 2005, Pages 238~242
DOI : 10.5483/BMBRep.2005.38.2.238
5-HT2A is one of major serotonin receptor that is involved in the action of serotonin-targeting drugs. Previous clinical studies have shown an unexpected association between lower cholesterol level and psychiatric diseases, in which T102C polymorphism of HTR2A, gene of 5-HT2A serotonin receptor, might be involved. Therefore, we hypothesized a potential association between lower cholesterol level and T102C polymorphism. The effect of the T102C polymorphism on the serum lipid profiles of 646 subjects without specific psychiatric disease was investigated. Genotype was determined by polymerase chain reaction and restriction fragment length polymorphism analysis. There were significantly lower levels of total cholesterol (
, p = 0.016) and HDL-cholesterol (
, p = 0.004) in CC genotype than non-CC genotypes. Moreover, multivariate analysis showed that the CC genotype is a strong predictor of a lower HDL-cholesterol level (p < 0.001). In conclusion, this study shows that the CC genotype of the HTR2A gene is related to lower HDL-cholesterol level in Koreans. This is the first demonstration showing the potential genetic relationship between the serotonin receptor gene polymorphism and the HDL-cholesterol level.
N Resonance Assignments and Molecular Interactions of the Dishevelled DIX Domain
Capelluto, Daniel G.S. ; Overduin, Michael ;
BMB Reports , volume 38, issue 2, 2005, Pages 243~247
DOI : 10.5483/BMBRep.2005.38.2.243
Dishevelled (Dvl) is a positive regulator of the canonical Wnt signaling pathway, which regulates the levels of
-catenin oncoprotein depends upon the association of Dvl and Axin proteins through their DIX domains, and its accumulation directs the expression of specific developmental-related genes at the nucleus. Here, the
resonances of the human Dishevelled 2 DIX domain are assigned using heteronuclear nuclear magnetic resonance (NMR) spectroscopy. In addition, helical and extended elements are identified based on the NMR data. The results establish a structural context for characterizing the actin and phospholipid interactions and binding sites of this novel domain, and provide insights into its role in protein localization to stress fibers and cytoplasmic vesicles during Wnt signaling.
Asparagine-473 Residue Is Important to the Efficient Function of Human Dihydrolipoamide Dehydrogenase
Kim, Hak-Jung ;
BMB Reports , volume 38, issue 2, 2005, Pages 248~252
DOI : 10.5483/BMBRep.2005.38.2.248
Dihydrolipoamide dehydrogenase (E3) catalyzes the reoxidation of dihydrolipoyl moiety of the acyltransferase components of three
-keto acid dehydrogenase complexes and of the hydrogen-carrier protein of the glycine cleavage system. His-457 of Pseudomonas putida E3 is suggested to interact with the hydroxyl group of Tyr-18 of the other subunit and with Glu-446, a component in the last helical structure. To examine the importance of the suggested interactions in human E3 function, the corresponding residue of human E3, Asn-473, was substituted to Leu using site-directed mutagenesis. The E3 mutant was expressed in Escherichia coli and highly purified using an affinity column. Its E3 activity was decreased about 37-fold, indicating that Asn-473 residue was important to the efficient catalytic function of human E3. Its slightly altered spectroscopic properties implied that small conformational changes could occur in the E3 mutant.
Glycoproteins Contained within Soamsan, a Traditional Oriental Medicine, are the Main Class of Active Ingredients Responsible for the Medicine-induced Immune Stimulation
Lee, Jeong-Chae ; Lee, Kyung-Yeol ; Jung, Ha-Na ; Kim, Jae-Gon ; Jang, Yong-Suk ;
BMB Reports , volume 38, issue 2, 2005, Pages 253~257
DOI : 10.5483/BMBRep.2005.38.2.253
In our previous study, Soamsan, a traditional Oriental medicine, was shown to enhance the induction of antigen-specific immune responses, and it was speculated that the enhancing activity might be closely associated with glycoproteins contained within the medicine. To elucidate this speculation, protein samples from each component, used in the preparation of Soamsan, were obtained and their immune stimulating activities were tested with mouse splenocytes. All the samples markedly enhanced the lymphocyte proliferation and cytokine secretion by the mouse splenocytes. In particular, the enhancement was significantly higher with the protein sample treatments than with those of the original crude sample. Furthermore, the pronase E- and
-mediated inhibition of splenocyte-stimulation activity of the protein samples clearly supported that glycoproteins are the main class of active ingredients responsible for the lymphocyte stimulating activity of the samples. Consequently, our findings suggest that glycoproteins might have a pivotal role in Soamsan-mediated immune modulation, although the in vivo effect of the glycoproteins should be further elucidated.