• Proceedings of the Korean Society of Sericultural Science Conference
• /
• 2003.04a
• /
• pp.31-32
• /
• 2003

Bacillus thuringiensis produces insecticidal parasporal inclusions (crystal protein) used as a major ingredient of most microbial insecticides. Although many B. thuringiensis strains and their crystal proteins have been isolated and characterized, such findings have limitation of usefulness. For enhanced toxicity, fast effects, and the delay of resistance development, research on genetic manipulation of crystal genes and proteins by genetic engineering should be continued. (omitted)

• Journal of Sericultural and Entomological Science
• /
• v.36 no.2
• /
• pp.157-161
• /
• 1994

To investigate the morphology of Bacillus thuringiensis crystal proteins, two type crystal protein genes, cryIA(c) gene under the control of cryIA(b) gene promoter and cryIIA gene under the control of its own promoter, were transformed in B. thuringiensis acrystalliferous mutant strain and the transformants were characterized by SDS-PAGE and scanning electron microscopy. The expression and formation of crystal proteins in B. thuringiensis subsp. kurstaki Cry-B revealed that crystal proteins appear to have same molecular weight and morphology to those of wild type strain's, suggesting that the expression and formation of crystal proteins affected not by host cell or recombination of cryIA(e) gene under the control of cryIA(b) gene promoter but by only structural fragment of protoxin.

• Bulletin of the Korean Chemical Society
• /
• v.33 no.5
• /
• pp.1577-1580
• /
• 2012

The orientational and dynamic behavior of liquid crystal molecules on the alignment layer surfaces of liquid crystal display (LCD) devices is crucial to their performance, but there are only a few methods of experimentally elucidating the interactions between the liquid crystals and the alignment layers. Inspired by the natural and technical similarities between membrane proteins in lipid bilayers and liquid crystals in LCDs, we employed solid-state NMR methodologies originally developed for the study of membrane proteins in lipid bilayers for the in-situ analysis of liquid crystal display panels. In this article, we present a home-built 500 MHz narrowbore (NB) The orientational and dynamic behavior of liquid crystal molecules on the alignment layer surfaces of liquid crystal display (LCD) devices is crucial to their performance, but there are only a few methods of experimentally elucidating the interactions between the liquid crystals and the alignment layers. Inspired by the natural and technical similarities between membrane proteins in lipid bilayers and liquid crystals in LCDs, we employed solid-state NMR methodologies originally developed for the study of membrane proteins in lipid bilayers for the in-situ analysis of liquid crystal display panels. In this article, we present a home-built 500 MHz narrowbore (NB) $^{19}F-^{13}C$ double resonance solid-state NMR probe with a flat-square coil and the first application of this probe for the in-situ analysis of LCD panel samples. double resonance solid-state NMR probe with a flat-square coil and the first application of this probe for the in-situ analysis of LCD panel samples.

• Bulletin of the Korean Chemical Society
• /
• v.31 no.9
• /
• pp.2627-2632
• /
• 2010

Hormone sensitive lipase (HSL) plays a major role in energy homeostasis and lipid metabolism. Several crystal structures of HSL-homolog proteins have been identified, which has led to a better understanding of its molecular function. HSL-homolog proteins exit as both monomer and dimer, but the biochemical and structural basis for such oligomeric states has not been successfully elucidated. Therefore, we determined the crystal structure of HSL-homolog protein EstE7 from a metagenome library at $2.2\;{\AA}$ resolution and characterized the oligomeric states of EstE7 both structurally and biochemically. EstE7 protein prefers the dimeric state in solution, which is supported by its higher enzymatic activity in the dimeric state. In the crystal form, EstE7 protein shows two-types of dimeric interface. Specifically, dimerization via the external ${beta}8$-strand occurred through tight association between two pseudosymmetric folds via salt bridges, hydrogen bonds and van der Waals interactions. This dimer formation was similar to that of other HSL-homolog protein structures such as AFEST, BEFA, and EstE1. We anticipate that our results will provide insight into the oligomeric state of HSL-homolog proteins.

• Journal of Life Science
• /
• v.6 no.4
• /
• pp.293-298
• /
• 1996

Thirteen subspecies of Bacillus thuringiensis including B. t. israelensis, B. t. morrisoni PG-14 and B.t. darmstadoemsos known to be toxic to dipteran insects were treated on the mushroom (Flammulina velutipes) compost to estimate the biological control effect of a sciarid fly, Lycoriella sp. According to the results, it was found that there were no significant effects of the tested strains of B, thuringiensis on the control of Lycoriella sp. For further confirmation, larval gut juice of Lycoriella sp. and trypsin were respectively treated into the parasporal crystal proteins of three subspecies of B. t. israelensis, B. t. morrisoni PG-14, and B. t. darmstadiensis. The proteins were separated by SDS-PAGE. According to the results, the major parasporal crystal proteins were respectively produced by B. t. morrisoni as the amount of 52 kd, B. y. israelensis as 37kd and B. t. darmstadiensis as 39kd, but the activity of these proteins could not be unfortunately confirmed in this study.

• Journal of Microbiology and Biotechnology
• /
• v.17 no.9
• /
• pp.1498-1503
• /
• 2007

To identify novel crystal proteins, Bacillus thuringiensis 2385-1 was isolated from Korean soil samples and characterized. The H-serotype of 2385-1 was identical to that of subsp. kenyae (H4a4c), and its crystal toxin was bipyramidal-shaped. However, 2385-1 showed a much higher toxicity towards Plutella xylostella and Spodoptera exigua larvae than subsp. kenyae. In addition, the crystal protein profile and plasmid DNA pattern of 2385-1 differed from those of subsp. kenyae. To verify the crystal protein gene types of 2385-1, a PCR-RFLP analysis was performed, and the results revealed that 2385-1 contained two novel cry1-type crystal protein genes, cryl-5 and cry1-12, in addition to the crylJal gene. The deduced amino acid sequences of cryl-5 and cry1-12 showed a 97.9% and 75.7% sequence similarity with the CrylAb and CrylJa crystal proteins, respectively. Among the novel crystal proteins, Cry1-5 showed a high toxicity towards P. xylostella and S. exigua larvae. In conclusion, B. thuringiensis 2385-1 is a new isolate in terms of its gene types, and should be a promising source for an insecticide to control lepidopteran larvae.

• Applied Biological Chemistry
• /
• v.39 no.3
• /
• pp.177-182
• /
• 1996

Effects of 14 carbohydrates supplied as carbon sources on cell growth and sporulation of, and the production of insecticidal crystal proteins by Bacillus thuringiensis strains were investigated in liquid cultures. Strains grew well in media containing any one of the 14 carbohydrates supplied, reaching maximum cell densities of $10^7{\sim}10^8\;cells/ml$ in 16.7 to 22 hours after inoculation depending on the strain. Spores first appeared in 16.7 to 24.7 hours after inoculation, and 80% sporulation was reached in 28 to 51.3 hours after inoculation depending on the strain. No change in pH of media was observed after cell multiplication. The production of total protein was highest when supplied with sucrose and was lowest with starch. More insecticidal crystal proteins were produced when supplied with glucose, lactose, maltose, or sucrose. The amount of insecticidal crystal proteins produced by the strains was proportional to that of the total protein. The relative amount of individual insecticidal crystal protein species produced by B.t. kurstaki and B.t. israelensis was not influenced by the carbohydrates supplied.

• Proceedings of the Korea Crystallographic Association Conference
• /
• 2003.05a
• /
• pp.15-15
• /
• 2003

To discover new drugs more quickly and more efficiently, pharmaceutical companies and biotechnology firms are increasingly turning to the genomics and the structural proteomics technologies. Structural-proteomics can provide a foundation for this through the determination and analysis for protein structure on a genomics scale. Among many structures determined by CGI, we will present with the representative examples drawn from our work on novel structures or complex structures of the disease-related proteins. The alpha subunit of Hypoxia-inducible factor (HIF) is targeted for degradation under normoxic conditions by an ubiquitin-ligase complex that recognizes a hydroxylated proline residue in HIF. Hydroxylation is catalysed by HIF prolyl 4-hydroxylases (HIFPH) which are fe(II) and 2-oxoglutarate (2-OG) dependent oxygenases. Here, we discuss the first crystal structure of the catalytic domain of HIFPH in complexes, with the Fe(II)/2-OG at 1.8Å. These structures suggest that the Ll region (residues 236-253), which is also conserved in mammals, form a 'lid' that closes over the active site. The structural and mutagenesis analyses allow us to provide a focus for understanding cellular responses to hypoxia and a target for the therapeutic manipulation.

• Proceedings of the Korean Biophysical Society Conference
• /
• 2003.06a
• /
• pp.28-28
• /
• 2003

To discover new drugs more quickly and more efficiently, pharmaceutical companies and biotechnology firms are increasingly turning to the genomics and the structural proteomics technologies. Structural-proteomics can provide a foundation for this through the determination and analysis for protein structure on a genomics scale. Among many structures determined by CGI, we will present with the representative examples drawn from our work on novel structures or complex structures of the disease-related proteins. The alpha subunit of Hypoxia-inducible factor (HIF) is targeted for degradation under normoxic conditions by an ubiquitin-ligase complex that recognizes a hydroxylated proline residue in HIF, Hydroxylation is catalysed by HIF prolyl 4-hydroxylases (HIFPH) which are Fe(II) and 2-oxoglutarate (2-OG) dependent oxygenases. Here, we discuss the first crystal structure of the catalytic domain of HIFPH in complexes, with the Fe(II)/2-OG at 1.8 ${\AA}$. These structures suggest that the L1 region (residues 236-253), which is also conserved in mammals, form a ‘lid’ that closes over the active site. The structural and mutagenesis analyses allow us to provide a focus for understanding cellular responses to hypoxia and a target for the therapeutic manipulation.

• Journal of Sericultural and Entomological Science
• /
• v.37 no.2
• /
• pp.176-180
• /
• 1995

To characterize expression and formation of three type crystal proteins in transformant, Bacillus thruingiensis PT0529 was analysed by transmission electron microscope and SDS-PAGE according to growth. The results showed that the introduced crystal protein genes, rcyIVD and cytA, were well expressed at earlier stage than resident crystal proteins were also expressed with their own morphology. However, resident crystal protein of B. thuringiensis PT0529 was smaller than that of wild type B. thuringiensis NT0423, suggesting that resident crystal protein production was interfered with introduced two type crystal protein genes.