• BMB Reports
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• v.40 no.5
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• pp.783-790
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• 2007

Receptor binding plays an important role in determining host specificity of the Bacillus thuringiensis Cry $\delta$-endotoxins. Mutations in domains II and III have suggested the participation of certain residues in receptor recognition and insect specificity. In the present study, we expressed the cloned domain II-III fragment of Cry4Ba and examined its binding characteristics to mosquito-larval midgut proteins. The 43-kDa Cry4Ba-domain II-III protein over-expressed in Escherichia coli as inclusion bodies was only soluble when carbonate buffer, pH 10.0 was supplemented with 4M urea. After renaturation via stepwise dialysis and subsequent purification, the refolded domain II-III protein, which specifically reacts with anti Cry4Ba-domain III monoclonal antibody, predominantly exists as a $\beta$-sheet structure determined by circular dichroism spectroscopy. In vitro binding analysis to both histological midgut tissue sections and brush border membrane proteins prepared from susceptible Aedes aegypti mosquito-larvae revealed that the isolated Cry4Ba-domain II-III protein showed binding functionality comparable to the 65-kDa full-length active toxin. Altogether, the data present the 43-kDa Cry4Ba fragment comprising domains II and III that was produced in isolation was able to retain its receptor-binding characteristics to the target larval midgut proteins.

• Bulletin of the Korean Chemical Society
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• v.29 no.2
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• pp.381-388
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• 2008

An X-linked skeletal disorder, SEDT (spondyloepiphyseal dysplasia tarda) is a genetic disease characterized by a disproportionately short trunk and short stature caused by mutations in the SEDL gene. This gene is evolutionarily conserved from yeast to human. The yeast SEDL protein ortholog, Trs20p, has been isolated as a member of a large multi-protein complex called the transport protein particle (TRAPP), which is involved in endoplasmic reticulum (ER)-to-Golgi transport. The interaction between SEDL and partner proteins is important in order to understand the molecular mechanism of SEDL functions. We isolated several SEDL-binding proteins derived from rat cells by an immobilized GST-fusion method. Furthermore, the SEDL-homologue proteins were identified using motif based methods. Common motifs between SEDL-binding proteins and SEDL-homologue proteins were classified into seven types and 78 common motifs were revealed. Sequence similarities were contracted to seven types using phylogenetic trees. In general, types I-III and VI were classified as having the function of acetyl-CoA carboxylase, glycogen phosphorylase, isocitrate dehydrogenase, and enolase, respectively, and type IV was found to be functionally related to the GST protein. Types V and VII were found to contribute to TRAPP vesicle trafficking.

• Proceedings of the Korean Biophysical Society Conference
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• 2001.06a
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• pp.43-43
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• 2001

In cells of the eukaryotic microorganism Dictyostelium discoideum, at least eight small, four-EF hand calcium-binding proteins respectively are expressed at specific stages during development. One of these proteins, calcium-binding protein 3 (CBP3), first appears just prior to cell aggregation and then maintains relatively constant levels throughout development.(omitted)

• YAKHAK HOEJI
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• v.39 no.4
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• pp.380-384
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• 1995

The isoelelectric points of Cd-BP(l) and Cd-BP(II), cadmium-binding proteins, were 6.01 and 5.35, respectively. Both of them contained zinc. As for the amino acid composition, Cd-BP(I) contained a lot of glycine and lysine but none of such aromatic amino acids as tyrosine and phenylalanine.. On the other hand, Cd-BP(II) contained leucine, histidine, asparti cacid and alanine but no aromatic amino acids.

• Molecules and Cells
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• v.20 no.2
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• pp.297-302
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• 2005

The integrity and proper functioning of telomeres require association of telomeric DNA sequences with specific binding proteins. We have characterized PLP-1, a $PUR{\alpha}$ homolog encoded by F45E4.2, which we previously identified as a candidate double stranded telomere binding protein, by affinity chromatography followed by mass spectrometry. PLP-1 bound double-stranded telomeric DNA in vitro as shown by competition assays. Core binding was provided by the third and fourth nucleotides of the TTAGGC telomeric repeat. This is quite different from the binding sequence of CEH-37, another C. elegans telomere binding protein, suggesting that multiple proteins may bind nematode telomeric DNA simultaneously in vivo.

• Proceedings of the Korean Biophysical Society Conference
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• 1996.07a
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• pp.9-9
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• 1996

The immunosuppressive and cell cycle arrest agent rapamycin works by binding together two proteins: the FK506 binding protein (FKBP12) and the FKBP-rapamycin associated protein (FRAP). A 2.7 $\AA$ resolution crystal structure of the triple complex of human FK506 binding protein (FKBP12), rapamycin, and FKBP12-rapamycin binding domain (FRB) of FRAP, reveals two proteins bound together through rapamycin' s ability to simultaneously occupy two different hydrophobic binding pockets. (omitted)

• Journal of Microbiology
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• v.33 no.3
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• pp.191-195
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• 1995

IciA protein has been shown as an inhibitor for the initiation of E. coli chromosomal DNA replication at oriC. IciA protein binds the AT-rich region in oriC and then blocks the initiation of chromosomal DNA replication. Two binding sites for IciA protein were identified in dnaA gene, encoding the initiator for the E. coli chromosomal replication, promoter region by gel-shift assay and DNase I footprinting, One, named as IciA site I, is located upstream of the dnaA promoter 1P. The other, named as IciA site II, is located downstream of the dnaA promoter 2P. The sequence comparison of the regions protected from the DNase I cleavage did not result in a clear consensus sequence for the binding of IciA protein, suggesting that IciA protein may be a member of multimeric complex dsDNA binding proteins. This study provided information about the binding mode of IciA protein. Even though the IciA site II and IciA binding site in oriC seem to be composed of two IciA binding units, one binding unit is likely enough to cause the binding of IciA protein to the IciA site I. The binding of IciA protein to the dna4 promoter implies that IciA protein may involve not only the control of the initiation of chromosomal DNA replication but also the control of the dna4 gene expression.

• Biomedical Science Letters
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• v.10 no.4
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• pp.407-413
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• 2004

Heterotrimeric GTP binding proteins (G proteins) transduce signals of a variety of hormones and neurotransmitters. Go is one of the most abundant G proteins in the brain and classified as the Gi/Go family due to their sequence homology to Gi proteins. While the Gi proteins inhibit adenylyl cyclase and decrease the intracellular cAMP concentration, the functions of Go is not clearly understood despite their sequence homology to Gi. The promeylocytic leukemia zinc finger protein (PLZF) is a DNA binding transcription factor and is expressed highly in central nervous system (CNS). Several studies reported that PLZF may be involved in regulation segmentation/differentiation during CNS development. Here, I report that the alpha subunit of Go (Go ) interacts with PLZF. The interaction between Goa and PLZF was verified by using GST pulldown assay and co-immunoprecipitation. Our findings indicate that Goa could modulate gene expression via interaction with PLZF during neuronal or brain development.

• Journal of Korean Neurosurgical Society
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• v.45 no.4
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• pp.231-235
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• 2009

Objective : While many factors contribute to aging, changes in calcium homeostasis and calcium related neuronal processes are likely to be important. High intracellular calcium is toxic to cells and alterations in calcium homeostasis are associated with changes in calcium-binding proteins, which confine free $Ca^{2+}$. We therefore assayed the expression of the calcium binding proteins calretinin and calbindin in the central auditory nervous system of rats. Methods : Using antibodies to calretinin and calbindin, we assayed their expression in the cochlear nucleus, superior olivary nucleus, inferior colliculus, medial geniculate body and auditory cortex of young (4 months old) and aged (24 months old) rats. Results : Calretinin and calbindin staining intensity in neurons of the cochlear nucleus was significantly higher in aged than in young rats (p<0.05) The number and staining intensity of calretinin-positive neurons in the inferior colliculus, and of calbindin-positive neurons in the superior olivary nucleus were greater in aged than in young rats (p<0.05). Conclusion : These results suggest that auditory processing is altered during aging, which may be due to increased intracellular $Ca^{2+}$ concentration, consequently leading to increased immunoreactivity toward calcium-binding proteins.

• Journal of the Korean Wood Science and Technology
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• v.33 no.1 s.129
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• pp.1-6
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• 2005

This research was performed to investigate the expression patterns of odorant-binding proteins (OBPs) migrating hydrophobic semiochemicals such as pheromone to the olfactory receptors in a termite (Reticulitermes speratus). Antennas and legs were cut from soldier and worker termites, respectively, and RT-PCR were conducted to investigate the existence of the OBPs reported up to now. Blast search suggested that the OBPs obtained were highly homologues of the OBPs reported. In worker termites, OBP-1 was expressed in both antennas and legs, OBP-2 and OBP-3 were observed only in antennas. And in soldier termites, OBP-1 was shown in both antennas and legs, OBP-2 were not observed, and OBP-3 was found in both antennas and legs. The differences of expression patterns of OBPs between worker and soldier termites may be explained by their specialized peculiarity.