• 한국발생생물학회지:발생과생식
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• 제16권4호
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• pp.379-384
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• 2012

Lhx8 (LIM homeobox 8) gene encodes a LIM homeodomain transcriptional regulator that is preferentially expressed in germ cells and critical for mammalian folliculogenesis. However, Lhx8 DNA binding sequences are not characterized yet. We aimed to identify and characterize a cis-acting sequence of germ-cell specific transcriptional factor, Lhx8. To identify Lhx8 DNA binding element, Cyclic Amplification of Sequence Target (CAST) Analysis was performed. Electrophoretic Mobility Shift Assay (EMSA) was processed for the binding specificity of Lhx8. Luciferase assay was for the transcriptional activity of Lhx8 through identified DNA binding site. We identified a putative cis-acting sequence, TGATTG as Lhx8 DNA binding element (LBE). In addition, Lhx8 binds to the LBE with high affinity and augments transcriptional activity of luciferase reporter driven by artificial promoter containing the Lhx8 binding element. These findings indicate that Lhx8 directly regulates the transcription of genes containing Lhx8 binding element in oocytes during early folliculogenesis.

• Journal of Microbiology and Biotechnology
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• 제17권7호
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• pp.1191-1197
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• 2007

The detection and kinetics of mucosal pathogenic bacteria binding on polysaccharide ligands were studied using a surface plasmon resonance biosensor. The kinetic model applied curve-fitting to the experimental surface plasmon resonance sensorgrams to evaluate the binding interactions. The kinetic parameters for the mucosal pathogenic bacteria (Pseudomonas aeruginosa, Pseudomonas fluorescens, Serratia marcescens) with the alginate ligand were determined from a kinetic model. In addition, the binding interactions of the mucosal pathogenic bacteria with polysaccharide binding pairs (Pseudomonas aeruginosa/alginate, Streptococcus pneumoniae/pneumococcal polysaccharide, Staphylococcus aureus/pectin) were also compared with their kinetic parameters. The rate constants of association for Pseudomonas aeruginosa with the alginate ligand were higher than those for Pseudomonas fluorescens. Serratia marcescens had no detectable interaction with the alginate ligand. The adhesion affinity of Pseudomonas aeruginosa with alginate was higher than that for the other binding pairs. The binding affinities of the pathogenic bacteria with their own polysaccharide were higher than that of Staphylococcus aureus with pectin. Measuring the contact angle was found to be a feasible method for detecting binding interactions between analytes and ligands.

• Biotechnology and Bioprocess Engineering:BBE
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• 제6권2호
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• pp.89-94
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• 2001

The binding of cellobiohydrolases to cullulose is a crucial initial step in cellulose hydrolysis. In the search for a detailed understanding of the function of cellobiohydrolases, much information concerning how the enzymes and their constituent catalytic and cellulose-binding changes during hydrolysis is still needed. The adsorption of purified two cellobiohydrolases (Ce17A and Ce16A) from Trichoderma reesei cellulase to microcrystalline cellulose has been studied. Cellobiohydrolase II (Ce16A) does not affect the adsorption of cellobiohydrolase I (Ce17A) significantly, and there are specific binding sites for both Ce17A and Ce16A. The adsorption affinity and tightness of the cullulase binding domain (CBD) for Ce17A are larger than those of the CBD for Ce16A. The CBD for Ce17A binds more rapidly and tightly to Avicel than the CBD for Ce16A. The decrease in adsorption observed when the two cellobihydrolases are studied together would appear to be the result of competition for binding sites on the cellulose. Ce17A competes more efficiently for binding sites than Ce16A. Competition for binding sites is the dominating factor when the two enzymes are acting together, furthermore adsorption to sites specific for Ce17A and Ce16A, also contributes to the total adsorption.

• BMB Reports
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• 제29권6호
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• pp.525-529
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• 1996

Ligand binding properties of muscarinic acetylcholine receptors (mAChRs) in the nematode Caenorhabditis elegans (C. elegans) were characterized by using filtration binding assays. Scatchard analysis using $[^{3}H]N-methylscopolamine$ ($[^{3}H]NMS$) showed that the dissociation constant ($K_d$) and the maximum binding value ($B_{max}$) were $3.3{\pm}0.8{\times}10^{10}$ M and $9.0{\pm}1.1$ fmol/mg protein, respectively. Binding competition experiments indicated that the affinities of C. elegans mAChRs to atropine, scopolamine, and oxotremorine were similar to those of mammalian mAChRs. Pirenzepine binding experiments revealed that the binding pattern of mAChRs in C. elegans closely resembled that of mAChRs in rat brain, suggesting that the receptors consist primarily of Ml subtype. The affinity of mAChRs for oxotrernorine was significantly affected by guanylylimidodiphosphate (Gpp(NH)p), a non hydrolyzable GTP analog, suggesting that mAChRs in C. elegans might be coupled to G proteins. The data presented here indicate the possibility that C. elegans provides a living animal model to study the action mode of the muscarinic cholinergic system.

• 대한수의학회지
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• 제37권2호
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• pp.301-310
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• 1997

Diabetes mellitus is associated with a wide range of pathophysiological in the kidney. This study was designed to examine the effects of high glucose concentration on IGF-I binding and glucose transporters in renal proximal tubule cells. The results were as follows : The binding of $^{125}I-IGF-I$ reached the peak at the 30 minutes and gradually decreased by the time dependent manner. The binding of $^{125}I-IGF-I$ was inhibited by the unlabelled IGF-I($10^{-14}{\sim}10^{-8}M$) in a concentration dependent manner. The relative affinity of IGF-I receptor for IGF-I, IGF-II and insulin exhibited typical type 1 binding(IGF-I > insulin > IGF-II). However IGF-II did not compete for the cultured cell membrane $^{125}I-IGF-I$ binding site at $10^{-14}{\sim}10^{-8}M$. Under optimal conditions, IGF-I binding to the membranes from 5mM and 20mM glucose treated cells was analyzed. It was found that 20mM glucose treated cells exhibited higher binding activity for IGF-I. In order to further substantiate this increase in IGF-I binding sites, we performed affinity-labelling studies. The cross-linked cell membrane subjected to SDS-PAGE; labelled material was detected by autoradiography. 20mM glucose treated cells exhibited higher levels. The initial rate of $methyl-{\alpha}-D-glucopyranoside({\alpha}-MG)$ uptake was significantly lower($74.41{\pm}6.71%$) in monolayers treated with 20mM glucose than those of 5mM glucose. However, 3-O-methyl-D-glucose(3-O-MG) uptake was not affected by glucose concentration in culture media. IGF-I significantly increased ${\alpha}-MG$ uptake in both 5mM and 20mM glucose treated cells. However, 3-O-MG uptake was not affected by IGF-I in both conditions. In conclusion, 20mM glucose increased binding sites of $^{125}I-IGF-I$, inhibited Na/glucose cotransporter activity. But 20mM glucose did not change facilitated glucose transporter.

• 미생물학회지
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• 제27권2호
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• pp.108-116
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• 1989

액포에 존재하는 arginine 운반체의 인식 특이성에 근거하여 NBZ arginyl diazomethane을 합성, affinity label로 사용하였다. 이 arginyl derivative는 ATP-dependent와 ATP-indepndent에 의한 arginine 운반작용을 억제하였다. 액포에의 결합은 비역가적이며, 강한 염기에 의해 분리되었다. Cysteine을 blocking 시키면, 결합은 일어나지 않았다.

• 약학회지
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• 제47권3호
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• pp.176-179
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• 2003

A library of unlimited number of novel lectins with diverse specificities has been previously generated by randomly mutating the carbohydrate-recognition domain of Maackia amurensis hemagglutinin (MAH). To establish the experimental environment capable of selecting high affinity mutant lectins in E. coli, phage display system was adapted. Carbohydrate binding capacity of two phagemid vectors, pComb3 and pComb8 displaying wild-type MAH lectin was assessed. Specific bindings of pComb3 and pComb8 phages expressing w.t. MAH to affinity-purified polyclonal anti-MAH antibody and to glycophorin was demonstrated. Both phages also showed strong hemagglutinating activity to intact but not sialidase-treated human erythrocytes, which is consistent to the specificity of native MAH. Taken together, two different phage display vectors successfully allowed the expression of active MAH as a fusion protein on the surface of bacteriophage, which will lead to preparation of unique plant lectins with high affinity toward a variety of carbohydrate chains.

• KSBB Journal
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• 제15권1호
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• pp.96-99
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• 2000

Octadetkanubc으로 수식된 아미노산을 DPPC 혹은 DSPC와 혼합하여 리포솜-아미노산 결합체를 제조하였다. 리포솜의 크기는 100nm이고 구형이었다. DPPC와 글루탐산을 혼합하여 제조한 리포솜-아미노산 결합체가 글루타민이나 아스파라긴을 사용했을 때보다 포도당과의 친화성이 컸다. 제조한 리포솜의 안정성 면에서도 DPPC와 glucamic acid으로 구성된 리포솜-아미노산 결합체의 안정성이 높았다. 결국 포도당 친화성과 안정성을 갖춘 리포솜은 DPPC 와 글루탐산의 비가 7 : 3 으로 제조된 리포솜이었다.

• Journal of Microbiology
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• 제44권5호
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• pp.508-514
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• 2006

In this study, the double-stranded DNA-dependent activities of Deinococcus radiodurans RecA protein (Dr RecA) were characterized. The interactions of the Dr RecA protein with double-stranded DNA were determined, especially dsDNA-dependent ATP hydrolysis by the Dr RecA protein and the DNA strand exchange reaction, in which multiple branch points exist on a single RecA protein-DNA complex. A nucleotide cofactor (ATP or dATP ) was required for the Dr RecA protein binding to duplex DNA. In the presence of dATP, the nucleation step in the binding process occurred more rapidly than in the presence of ATP. Salts inhibited the binding of the Dr RecA protein to double-stranded DNA. Double-stranded DNA-dependent ATPase activities showed a different sensitivity to anion species. Glutamate had only a minimal effect on the double-stranded DNA-dependent ATPase activities, up to a concentration of 0.7 M. In the competition experiment for Dr RecA protein binding, the Dr RecA protein manifested a higher affinity to double-stranded DNA than was observed for single-stranded DNA.

• 대한수의학회지
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• 제37권4호
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• pp.875-882
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• 1997

To produce the recombinant fibronectin-binding protein(FnBP) for development of subunit vaccine against Staphylococcus aureus. The fnbp gene was amplified from the chromosomal DNA of S aureus KNU 196 strain using the polymerase chain reaction, and cloned into pGEX-4T-2. Then, the recombinant FnBP fused with glutathione-S-transferase was produced in E coli, purified by affinity chromatography, and identified its antigenicity and immunogenicity by Western blot. The recombinant FnBP produced in this study is considered to have the same property of native FnBP purified from S aureus, and is expected to be useful as a candidate for S aureus subunit vaccine.