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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of Microbiology and Biotechnology
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Journal DOI :
The Korean Society for Applied Microbiology and Biotechnology
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Volume & Issues
Volume 24, Issue 5 - May 2014
Volume 24, Issue 4 - Apr 2014
Volume 24, Issue 3 - Mar 2014
Volume 24, Issue 2 - Feb 2014
Volume 24, Issue 1 - Jan 2014
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Construction of a Shuttle Vector for Protein Secretory Expression in Bacillus subtilis and the Application of the Mannanase Functional Heterologous Expression
Guo, Su ; Tang, Jia-Jie ; Wei, Dong-Zhi ; Wei, Wei ;
Journal of Microbiology and Biotechnology, volume 24, issue 4, 2014, Pages 431~439
DOI : 10.4014/jmb.1311.11009
We report the construction of two Bacillus subtilis expression vectors, pBNS1/pBNS2. Both vectors are based on the strong promoter P43 and the ampicillin resistance gene expression cassette. Additionally, a fragment with the Shine-Dalgarno sequence and a multiple cloning site (BamHI, SalI, SacI, XhoI, PstI, SphI) were inserted. The coding region for the amyQ (encoding an amylase) signal peptide was fused to the promoter P43 of pBNS1 to construct the secreted expression vector pBNS2. The applicability of vectors was tested by first generating the expression vectors pBNS1-GFP/pBNS2-GFP and then detecting for green fluorescent protein gene expression. Next, the mannanase gene from B. pumilus Nsic-2 was fused to vector pBNS2 and we measured the mannanase activity in the supernatant. The mannanase total enzyme activity was 8.65 U/ml, which was 6 times higher than that of the parent strain. Our work provides a feasible way to achieve an effective transformation system for gene expression in B. subtilis and is the first report to achieve B. pumilus mannanase secretory expression in B. subtilis.
Improving Endoglucanase Activity by Adding the Carbohydrate-Binding Module from Corticium rolfsii
Tang, Zizhong ; Chen, Hui ; Chen, Lijiao ; Liu, San ; Han, Xueyi ; Wu, Qi ;
Journal of Microbiology and Biotechnology, volume 24, issue 4, 2014, Pages 440~446
DOI : 10.4014/jmb.1311.11007
The carbohydrate-binding module (CBM) is an important domain of most cellulases that plays a key role in the hydrolysis of cellulose. The neutral endoglucanase (EG1) gene was reconstructed. A redesigned endoglucanase, named EG2, was constructed with a CBM containing a linker from Corticium rolfsii (GenBank Accession No. D49448). The redesigned EG genes were expressed in Escherichia coli, and their characteristics are discussed. Results showed that the degradation of cellulose by EG2 was about double that by EG1. The specific activities of EG1 and EG2 were tested under optimal conditions, and EG2 had higher activity (
U/mg) toward CMC-Na than did EG1 (
) in the process of cellulose degradation. The optimal pH and temperature, pH stability, and heat stability of EG1 and EG2 were similar. Results indicated that the CBM plays an essential role in the hydrolysis of cellulose. We can improve EG's catalytic power by adding the CBM from Corticium rolfsii.
Cloning and Characterization of a Novel
-Amylase from a Fecal Microbial Metagenome
Xu, Bo ; Yang, Fuya ; Xiong, Caiyun ; Li, Junjun ; Tang, Xianghua ; Zhou, Junpei ; Xie, Zhenrong ; Ding, Junmei ; Yang, Yunjuan ; Huang, Zunxi ;
Journal of Microbiology and Biotechnology, volume 24, issue 4, 2014, Pages 447~452
DOI : 10.4014/jmb.1310.10121
To isolate novel and useful microbial enzymes from uncultured gastrointestinal microorganisms, a fecal microbial metagenomic library of the pygmy loris was constructed. The library was screened for amylolytic activity, and 8 of 50,000 recombinant clones showed amylolytic activity. Subcloning and sequence analysis of a positive clone led to the identification a novel gene (amyPL) coding for
-amylase. AmyPL was expressed in Escherichia coli BL21 (DE3) and the purified AmyPL was enzymatically characterized. This study is the first to report the molecular and biochemical characterization of a novel
-amylase from a gastrointestinal metagenomic library.
Fabrication of Biogenic Antimicrobial Silver Nanoparticles by Streptomyces aegyptia NEAE 102 as Eco-Friendly Nanofactory
El-Naggar, Noura El-Ahmady ; Abdelwahed, Nayera A.M. ; Darwesh, Osama M.M. ;
Journal of Microbiology and Biotechnology, volume 24, issue 4, 2014, Pages 453~464
DOI : 10.4014/jmb.1310.10095
The current research was focused on the extracellular biosynthesis of bactericidal silver nanoparticles (AgNPs) using cell-free supernatant of a local isolate previously identified as a novel Streptomyces aegyptia NEAE 102. The biosynthesis of silver nanoparticles by Streptomyces aegyptia NEAE 102 was quite fast and required far less time than previously published strains. The produced particles showed a single surface plasmon resonance peak at 400 nm by UV-Vis spectroscopy, which confirmed the presence of AgNPs. Response surface methodology was chosen to evaluate the effects of four process variables (
concentration, incubation period, pH levels, and inoculum size) on the biosynthesis of silver nanoparticles by Streptomyces aegyptia NEAE 102. Statistical analysis of the results showed that the linear and quadratic effects of incubation period, initial pH, and inoculum size had a significant effect (p < 0.05) on the biosynthesis of silver nanoparticles by Streptomyces aegyptia NEAE 102. The maximum silver nanoparticles biosynthesis (2.5 OD, at 400 nm ) was achieved in runs number 5 and 14 under the conditions of 1 mM
(1-1.5% (v/v)), incubation period (72-96 h), initial pH (9-10), and inoculum size (2-4% (v/v)). An overall 4-fold increase in AgNPs biosynthesis was obtained as compared with that of unoptimized conditions. The biosynthesized silver nanoparticles were characterized using UV-VIS spectrophotometer and Fourier transform infrared spectroscopy analysis, in addition to antimicrobial properties. The biosynthesized AgNPs significantly inhibited the growth of medically important pathogenic gram-positive (Staphylococcus aureus) and gram-negative bacteria (Pseudomonas aeruginosa) and yeast (Candida albicans).
Inhibitory Effects of Brown Algae Extracts on Histamine Production in Mackerel Muscle via Inhibition of Growth and Histidine Decarboxylase Activity of Morganella morganii
Kim, Dong Hyun ; Kim, Koth Bong Woo Ri ; Cho, Ji Young ; Ahn, Dong Hyun ;
Journal of Microbiology and Biotechnology, volume 24, issue 4, 2014, Pages 465~474
DOI : 10.4014/jmb.1309.09071
This study was performed to investigate the inhibitory effects of brown algae extracts on histamine production in mackerel muscle. First, antimicrobial activities of brown algae extracts against Morganella morganii were investigated using a disk diffusion method. An ethanol extract of Ecklonia cava (ECEE) exhibited strong antimicrobial activity. The minimum inhibitory concentration (MIC) of ECEE was 2 mg/ml. Furthermore, the brown algae extracts were examined for their ability to inhibit crude histidine decarboxylase (HDC) of M. morganii. The ethanol extract of Eisenia bicyclis (EBEE) and ECEE exhibited significant inhibitory activities (19.82% and 33.79%, respectively) at a concentration of 1 mg/ml. To obtain the phlorotannin dieckol, ECEE and EBEE were subjected to liquid-liquid extraction, silica gel column chromatography, and HPLC. Dieckol exhibited substantial inhibitory activity with an
value of 0.61 mg/ml, and exhibited competitive inhibition. These extracts were also tested on mackerel muscle. The viable cell counts and histamine production in mackerel muscle inoculated with M. morganii treated with
MIC of ECEE (weight basis) were highly inhibited compared with the untreated sample. Furthermore, treatment of crude HD-Cinoculated mackerel muscle with 0.5% ECEE and 0.5% EBEE (weight basis), which exhibited excellent inhibitory activities against crude HDC, reduced the overall histamine production by 46.29% and 56.89%, respectively, compared with the untreated sample. Thus, these inhibitory effects of ECEE and EBEE should be helpful in enhancing the safety of mackerel by suppressing histamine production in this fish species.
Biotransformation of Eugenol via Protocatechuic Acid by Thermophilic Geobacillus sp. AY 946034 Strain
Giedraityte, Grazina ; Kalediene, Lilija ;
Journal of Microbiology and Biotechnology, volume 24, issue 4, 2014, Pages 475~482
DOI : 10.4014/jmb.1309.09069
The metabolic pathway of eugenol degradation by thermophilic Geobacillus sp. AY 946034 strain was analyzed based on the lack of data about eugenol degradation by thermophiles. TLC, GC-MS, and biotransformation with resting cells showed that eugenol was oxidized through coniferyl alcohol, and ferulic and vanillic acids to protocatechuic acid before the aromatic ring was cleaved. The cell-free extract of Geobacillus sp. AY 946034 strain grown on eugenol showed a high activity of eugenol hydroxylase, feruloyl-CoA synthetase, vanillate-O-demethylase, and protocatechuate 3,4-dioxygenase. The key enzyme, protocatechuate 3,4-dioxygenase, which plays a crucial role in the degradation of various aromatic compounds, was purified 135-fold to homogeneity with a 34% overall recovery from Geobacillus sp. AY 946034. The relative molecular mass of the native enzyme was about
kDa and was composed of the non-identical subunits. The pH and temperature optima for enzyme activity were 8 and
, respectively. The half-life of protocatechuate 3,4-dioxygenase at the optimum temperature was 50 min.
Thermostable Sites and Catalytic Characterization of Xylanase XYNB of Aspergillus niger SCTCC 400264
Li, Xin Ran ; Xu, Hui ; Xie, Jie ; Yi, Qiao Fu ; Li, Wei ; Qiao, Dai Rong ; Cao, Yi ; Cao, Yu ;
Journal of Microbiology and Biotechnology, volume 24, issue 4, 2014, Pages 483~488
DOI : 10.4014/jmb.1307.07086
In order to improve the expression of heat-resistant xylanase XYNB from Aspergillus niger SCTCC 400264, XynB has been cloned into Pichia pastoris secretary vector pPIC9K. The XynB production of recombinant P. pastoris was four times that of E. coli, and the
and specific activity of XynB reached
and 4,757 U/mg, respectively. XynB still had 74% residual enzyme activity after 30 min of heat treatment at
. From the van der Waals force analysis of XYNB (ACN89393 and AAS67299), there is one more oxygen radical in AAS67299 in their catalytic site, indicating that the local cavity is much more free, and it is more optimal for substrate binding, affinity reaction, and proton transfer, etc, and eventually increasing enzyme activity. The H-bonds analysis of XYNB indicated that there are two more H-bonds in the 33rd Ser of XYNB (AAS67299) than in the 33rd Ala(ACN89393 ), and two H-bonds between Ser70 and Asp67.
Purification and Characterization of a Thermostable Xylanase from Paenibacillus sp. NF1 and its Application in Xylooligosaccharides Production
Zheng, Hong-Chen ; Sun, Ming-Zhe ; Meng, Ling-Cai ; Pei, Hai-Sheng ; Zhang, Xiu-Qing ; Yan, Zheng ; Zeng, Wen-Hui ; Zhang, Jing-Sheng ; Hu, Jin-Rong ; Lu, Fu-Ping ; Sun, Jun-She ;
Journal of Microbiology and Biotechnology, volume 24, issue 4, 2014, Pages 489~496
DOI : 10.4014/jmb.1312.12072
High levels of extracellular xylanase activity (211.79 IU/mg) produced by Paenibacillus sp. NF1 were detected when it was submerged-cultured. After three consecutive purification steps using Octyl-Sepharose, Sephadex G75, and Q-Sepharose columns, a thermostable xylanase (XynNF) was purified to homogeneity and showed a molecular mass of 37 kDa according to SDS-PAGE. The specific activity of the purified XynNF was up to 3,081.05 IU/mg with a 14.55-fold purification. The activity of XynNF was stimulated by
, DTT, and
-mercaptoethanol, but was inhibited by
, SDS, and EDTA. The purified XynNF displayed a greater affinity for oat spelt xylan with the maximal enzymatic activity at
and pH 6.0. XynNF, which was shown to be cellulose-free, with high stability at high temperature (
) and low pH range (pH 4.0-7.0), is potentially valuable for various industrial applications. The enzyme hydrolyzed oat spelt xylan to yield mainly xylooligosaccharides (95.8%) of 2-4 degree of polymerization (DP2-4). Moreover, the majority of the xylooligosacharides (DP2-4) products was xylobiose (61.5%). The thermostable xylanase (XynNF) thus seems potentially usefull in the production of xylooligosaccharides.
Lipid and Citric Acid Production by Wild Yeasts Grown in Glycerol
Souza, Karla Silva Teixeira ; Schwan, Rosane Freitas ; Dias, Disney Ribeiro ;
Journal of Microbiology and Biotechnology, volume 24, issue 4, 2014, Pages 497~506
DOI : 10.4014/jmb.1310.10084
In this study, crude glycerol was used as a carbon source in the cultivation of wild yeasts, aiming at the production of microbial lipids and citric acid. Forty yeasts of different sources were tested concerning their growth in crude and commercial glycerol. Four yeasts (Lindnera saturnus UFLA CES-Y677, Yarrowia lipolytica UFLA CM-Y9.4, Rhodotorula glutinis NCYC 2439, and Cryptococcus curvatus NCYC 476) were then selected owing to their ability to grow in pure (
2.133, 1.633, 2.055, and 2.049, respectively) and crude (
2.354, 1.753, 2.316, and 2.281, respectively) glycerol (10%, 20%, and 30%). Y. lipolytica UFLA CM-Y9.4 was selected for its ability to maintain cell viability in concentrations of 30% of crude glycerol, and high glycerol intake (18.907 g/l). This yeast was submitted to lipid production in 30 g/l of crude glycerol, and therefore obtained 63.4% of microbial lipids. In the fatty acid profile, there was a predominance of stearic (C18:0) and palmitic (C16:0) acids in the concentrations of 87.64% and 74.67%, respectively. We also performed optimization of the parameters for the production of citric acid, which yielded a production of 0.19 g/l of citric acid in optimum conditions (38.4 g/l of crude glycerol, agitation of 184 rpm, and temperature of
). Yarrowia lipolytica UFLA CM-Y9.4 presented good lipid production when in the concentration of 30 g/l of glycerol. These data may be used for production in large quantities for the application of industrial biodiesel.
Development of a High Efficient "Dual Bt-Plus" Insecticide Using a Primary Form of an Entomopathogenic Bacterium, Xenorhabdus nematophila
Eom, Seonghyeon ; Park, Youngjin ; Kim, Hyeonghwan ; Kim, Yonggyun ;
Journal of Microbiology and Biotechnology, volume 24, issue 4, 2014, Pages 507~521
DOI : 10.4014/jmb.1310.10116
A phase variation has been reported in an entomopathogenic bacterium, Xenorhabdus nematophila. Compared with a wild-type primary form, a secondary form usually loses several physiological and biochemical characters. This study showed that the phase variation of X. nematophila caused a significant alteration in its immunosuppressive activity and subsequent entomopathogenicity. A secondary form of X. nematophila was detected in laboratory colonies and exhibited significant differences in dye absorption and entomopathogenicity. In addition, the secondary form was different in its production of eicosanoid-biosynthesis inhibitors (EBIs) compared with the primary form of X. nematophila. Production of oxindole and p-hydroxypropionic acid was significantly reduced in the culture broth of the secondary form of X. nematophila. The reduced EBI production resulted in significant suppression in the inhibitory effects on cellular nodule formation and phenoloxidase activity. Culture broth of the primary form of X. nematophila enhanced the pathogenicity of Bacillus thuringiensis ( Bt) significantly more than the culture broth of the secondary form. Furthermore, this study developed a highly efficient "Dual Bt-Plus: to control both lepidopteran insect pests Plutella xylostella and Spodoptera exigua, by mixing two effective Bt strains along with the addition of potent bacterial metabolites or 100-fold concentrated X. nematophila culture broth.
Microalga Scenedesmus sp.: A Potential Low-Cost Green Machine for Silver Nanoparticle Synthesis
Jena, Jayashree ; Pradhan, Nilotpala ; Nayak, Rati Ranjan ; Dash, Bishnu P. ; Sukla, Lala Behari ; Panda, Prasanna K. ; Mishra, Barada K. ;
Journal of Microbiology and Biotechnology, volume 24, issue 4, 2014, Pages 522~533
DOI : 10.4014/jmb.1306.06014
Bionanotechnology has revolutionized nanomaterial synthesis by providing a green synthetic platform using biological systems. Among such biological systems, microalgae have tremendous potential to take up metal ions and produce nanoparticles by a detoxification process. The present study explores the intracellular and extracellular biogenic syntheses of silver nanoparticles (SNPs) using the unicellular green microalga Scenedesmus sp. Biosynthesized SNPs were characterized by AAS, UV-Vis spectroscopy, TEM, XRD, FTIR, DLS, and TGA studies and finally checked for antibacterial activity. Intracellular nanoparticle biosynthesis was initiated by a high rate of
ion accumulation in the microalgal biomass and subsequent formation of spherical crystalline SNPs (average size, 15-20 nm) due to the biochemical reduction of
ions. The synthesized nanoparticles were intracellular, as confirmed by the UV-Vis spectra of the outside medium. Furthermore, extracellular synthesis using boiled extract showed the formation of well scattered, highly stable, spherical SNPs with an average size of 5-10 nm. The size and morphology of the nanoparticles were confirmed by TEM. The crystalline nature of the SNPs was evident from the diffraction peaks of XRD and bright circular ring pattern of SAED. FTIR and UV-Vis spectra showed that biomolecules, proteins and peptides, are mainly responsible for the formation and stabilization of SNPs. Furthermore, the synthesized nanoparticles exhibited high antimicrobial activity against pathogenic gram-negative and gram-positive bacteria. Use of such a microalgal system provides a simple, cost-effective alternative template for the biosynthesis of nanomaterials in a large-scale system that could be of great use in biomedical applications.
Effects of Microbial Iron Reduction and Oxidation on the Immobilization and Mobilization of Copper in Synthesized Fe(III) Minerals and Fe-Rich Soils
Hu, Chaohua ; Zhang, Youchi ; Zhang, Lei ; Luo, Wensui ;
Journal of Microbiology and Biotechnology, volume 24, issue 4, 2014, Pages 534~544
DOI : 10.4014/jmb.1310.10001
The effects of microbial iron reduction and oxidation on the immobilization and mobilization of copper were investigated in a high concentration of sulfate with synthesized Fe(III) minerals and red earth soils rich in amorphous Fe (hydr)oxides. Batch microcosm experiments showed that red earth soil inoculated with subsurface sediments had a faster Fe(III) bioreduction rate than pure amorphous Fe(III) minerals and resulted in quicker immobilization of Cu in the aqueous fraction. Coinciding with the decrease of aqueous Cu,
in the inoculated red earth soil decreased acutely after incubation. The shift in the microbial community composite in the inoculated soil was analyzed through denaturing gradient gel electrophoresis. Results revealed the potential cooperative effect of microbial Fe(III) reduction and sulfate reduction on copper immobilization. After exposure to air for 144 h, more than 50% of the immobilized Cu was remobilized from the anaerobic matrices; aqueous sulfate increased significantly. Sequential extraction analysis demonstrated that the organic matter/sulfide-bound Cu increased by 52% after anaerobic incubation relative to the abiotic treatment but decreased by 32% after oxidation, indicating the generation and oxidation of Cu-sulfide coprecipitates in the inoculated red earth soil. These findings suggest that the immobilization of copper could be enhanced by mediating microbial Fe(III) reduction with sulfate reduction under anaerobic conditions. The findings have an important implication for bioremediation in Cu-contaminated and Fe-rich soils, especially in acid-mine-drainage-affected sites.
Comparison of Two Laccases from Trametes versicolor for Application in the Decolorization of Dyes
Li, Qi ; Ge, Lin ; Cai, Junli ; Pei, Jianjun ; Xie, Jingcong ; Zhao, Linguo ;
Journal of Microbiology and Biotechnology, volume 24, issue 4, 2014, Pages 545~555
DOI : 10.4014/jmb.1310.10079
It has been previously demonstrated that laccases exhibit great potential for use in several industrial and environmental applications. In this paper, two laccase isoenzyme genes, lccB and lccC, were cloned and expressed in Pichia pastoris GS115. The sequence analysis indicated that the lccB and lccC genes consisted of 1,563 and 1,584 bp, and their open reading frames encoded 520 and 527 amino acids, respectively. They had 72.7% degree of identity in nucleotides and 86.7% in amino acids. The expression levels of LccB and LccC were up to 32,479 and 34,231 U/l, respectively. The recombinant laccases were purified by ultrafiltration and
precipitation, showing a single band on SDS-PAGE, which had a molecular mass of 58 kDa. The optimal pH and temperature for LccB were 2.0 and
with 2,2'-azinobis-[ 3-ethylbenzthiazolinesulfonic acid (ABTS) as a substrate, whereas LccC exhibited optimal pH and temperature at 3.0 and
. The apparent kinetic parameters of LccB were 0.43 mM for ABTS with a
value of 51.28 U/mg, and the Km and
values for LccC were 0.29 mM and 62.89 U/mg. The recombinant laccases were able to decolorize five types of dyes. Acid Violet 43 (100 g/ml) was completely decolorized by LccB or LccC (2 U/ml), and the decolorization of Reactive Blue KN-R (100 g/ml) was 91.6% by LccC (2 U/ml). Thus, the study characterizes useful laccase isoenzymes from T. versicolor that have the capability of being incorporated into the treatment of similar azo and anthraquinone dyes from dyeing industries.
Occurrence and Molecular Characterization of Noroviruses in Korean Surface Water Between 2007 and 2010
Lee, Gyu-Cheol ; Kim, Min-Jeong ; Kim, Jong Ik ; Lee, Chan Hee ;
Journal of Microbiology and Biotechnology, volume 24, issue 4, 2014, Pages 556~562
DOI : 10.4014/jmb.1311.11089
The occurrence of human norovirus (NoV) genogroup I (GI) and genogroup II (GII) strains was investigated in Korea. Between 2007 and 2010, 265 samples were collected from 89 Korean water source locations. NoV GI was detected in 4.5% and NoV GII in 1.5%. Samples collected in winter had the highest occurrence; 9.4% for NoV GI and 6.3% for NoV GII. NoV GI detection was highest in groundwater, with the next highest in river water and the lowest in lake water (5.9%, 5.4%, and 1.6%, respectively), and NoV GII was found only in river water. When three representative Korean basin systems (Han (H)-, Geum/Seom (G/S)-, and Nakdong (N)-river basins) were compared, both NoV genogroups were high in the G/S-, but absent in the H- river basin. The most prevalent genotypes within the GI and GII groups were GI.5 and GII.4, respectively. The NoVs found in surface water were identical to those found in patients and those found in groundwater. The NoVs appeared to be transmitted from the patient to the surface water, and then to the groundwater, suggesting a fecal-oral route of transmission. This is the first nationwide surveillance of NoV in major Korean water sources.
Genome Sequence and Comparative Genome Analysis of Pseudomonas syringae pv. syringae Type Strain ATCC 19310
Park, Yong-Soon ; Jeong, Haeyoung ; Sim, Young Mi ; Yi, Hwe-Su ; Ryu, Choong-Min ;
Journal of Microbiology and Biotechnology, volume 24, issue 4, 2014, Pages 563~567
DOI : 10.4014/jmb.1312.12082
Pseudomonas syringae pv. syringae (Psy) is a major bacterial pathogen of many economically important plant species. Despite the severity of its impact, the genome sequence of the type strain has not been reported. Here, we present the draft genome sequence of Psy ATCC 19310. Comparative genomic analysis revealed that Psy ATCC 19310 is closely related to Psy B728a. However, only a few type III effectors, which are key virulence factors, are shared by the two strains, indicating the possibility of host-pathogen specificity and genome dynamics, even under the pathovar level.
Construction and Characterization of an Enhanced GFP-Tagged TIM-1 Fusion Protein
Qing, Jilin ; Xiao, Haibing ; Zhao, Lin ; Qin, Guifang ; Hu, Lihua ; Chen, Zhizhong ;
Journal of Microbiology and Biotechnology, volume 24, issue 4, 2014, Pages 568~576
DOI : 10.4014/jmb.1311.11077
TIM-1 (also known as KIM-1 and HAVcr-1) is a type I transmembrane glycoprotein member of the TIM family that may play important roles in innate and adaptive immune responses. The overexpression of proteins associated with membrane proteins is a major obstacle to overcome in studies of membrane protein structures and functions. In this study, we successfully coupled the overexpression of the TIM-1 protein with a C-terminal enhanced green fluorescent protein (GFP) tag in Escherichia coli. To the best of our knowledge, this report is the first to describe the overexpression of human TIM-1 in E. coli. The purified TIM-1-EGFP fusion protein recognized and bound directly to apoptotic cells and did not to bind to viable cells. Furthermore, we confirmed that the interactions of TIM-1-EGFP with apoptotic cells were blocked by TIM-1-Fc fusion proteins. This fusion protein represents a readily obtainable source of biologically active TIM-1 that may prove useful in future studies of human TIM-1.
Comparison of the Effects of Retroviral Restriction Factors Involved in Resistance to Porcine Endogenous Retrovirus
Bae, Eun Hye ; Jung, Yong-Tae ;
Journal of Microbiology and Biotechnology, volume 24, issue 4, 2014, Pages 577~583
DOI : 10.4014/jmb.1312.12079
Three major classes of retroviral restriction factors (APOBEC3G, Tetherin, and TRIM5
) have been identified in mammals. Restriction factors are cellular proteins that are able to limit viral replication by targeting specific steps of the viral life cycle. To evaluate which restriction factor is the most effective to inhibit the replication of porcine endogenous retroviruses (PERVs), the antiviral activity of each restriction factor was compared. In pseudotype assay, the antiviral activity of human tetherin against PERV pseudotype was slightly weaker than that of human APOBEC3G (hA3G). A combination of tetherin and hA3G was more potent than each individual restriction factor. We questioned whether a combination of tetherin and hA3G could also inhibit the spreading replication of PERV. In agreement with the pseudotype assay, two restriction factors inhibit infectious PERV replication in a spreading infection. In this study, hA3G could strongly inhibit the replication of PERV, but tetherin modestly restricted it. Based on these results, we concluded that a combination of tetherin and hA3G is the most effective way to restrict PERV. A combination of different restriction factors will encourage the development of a new approach to treat retroviral disease.