• Bulletin of the Korean Chemical Society
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• v.35 no.9
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• pp.2665-2668
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• 2014

Aptamers are oligonucleotides or peptide molecules that are able to bind to their specific target molecules with high affinity via molecular recognition. In this study, we present development of aptamer-based precipitation assays (or simply aptamoprecipitation) for His-tagged proteins and thrombin to compare their purification efficiency with other conventional affinity precipitation methods. A crosslinking method was employed to immobilize thiol-functionalized aptamers onto the surface of polystyrene resins, enabling them to specifically bind to His-tag and to thrombin, respectively. The resulting aptamer-functionalized resins were successfully applied via a one-step experiment to purification of His-tagged proteins from complex E. coli and to thrombin extraction, exhibiting superior or at least comparable purification results to the conventional immobilized metal affinity precipitation or immunoprecipitation.

• BMB Reports
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• v.49 no.6
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• pp.319-324
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• 2016

RNA polymerase II C-terminal domain phosphatases are newly emerging family of phosphatases that contain FCPH domain with Mg⁺²-binding DXDX(T/V) signature motif. Its subfamily includes small CTD phosphatases (SCPs). Recently, we identified several interacting partners of human SCP1 with appearance of dephosphorylation and O-GlcNAcylation. In this study, using an established cell line with inducible CTDSPL2 protein (a member of the new phosphatase family), proteomic screening was conducted to identify binding partners of CTDSPL2 in nuclear extract through immunoprecipitation of CTDSPL2 with its associated. This approach led to the identification of several interacting partners of CTDSPL2. This will provide a better understanding on CTDSPL2.

• Journal of Microbiology and Biotechnology
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• v.1 no.4
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• pp.232-239
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• 1991

Caboxymethyl cellulase (CMCase) I was purified from the induced culture filtrate of Penicllium verruculosum F-3 by ammonium sulfate precipitation, DEAE-Sephadex A-50 chromatography and Bio-gel P-150 filtration. The purified enzyme was assumed to be a glycoprotein consisting of 8.5% carbohydrate and having a molecular weight of 70.000 in SDS-polycrylamide gel electrophoresis (SDS-PAGE). The purified enzyme-specific anti-CMCase I IgG was obtained by rabbit immunization and protein A-sepharose CL-4B chromatography. The fungal poly($A^+$) RNA was isolated from the total RNA of the mycelium grown under cellulase induction conditions by oligo(dT)-cellulosse chromatography. The translation products in vitro were prepared by translating the isolated poly ($A^+$) RNA in rabbit reticulocyte lysate and analyzed by SDS-PAGE and fluorography. Of the translation products, CMCase I was identified by the immunoprecipitation against anti-CMCase I IgG.

• Genomics & Informatics
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• v.12 no.4
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• pp.145-150
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• 2014

Recent technical advances, such as chromatin immunoprecipitation combined with DNA microarrays (ChIp-chip) and chromatin immunoprecipitation-sequencing (ChIP-seq), have generated large quantities of high-throughput data. Considering that epigenomic datasets are arranged over chromosomes, their analysis must account for spatial or temporal characteristics. In that sense, simple clustering or classification methodologies are inadequate for the analysis of multi-track ChIP-chip or ChIP-seq data. Approaches that are based on hidden Markov models (HMMs) can integrate dependencies between directly adjacent measurements in the genome. Here, we review three HMM-based studies that have contributed to epigenetic research, from a computational perspective. We also give a brief tutorial on HMM modelling-targeted at bioinformaticians who are new to the field.

• YAKHAK HOEJI
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• v.50 no.4
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• pp.263-267
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• 2006

CD1d is an unique antigen presenting molecule which provides antigenic repertoires to NKT cells. To examine molecules required for CD1d antigen presentation, we determined an interaction between CD1d and several endoplasmic reticulum (ER) resident molecular chaperones by co-immunoprecipitation. Results indicated that calnexin and calreticulin seem to be bound to mouse CD1d, but TAP and tapasin do not bind. Further, we screened an yeat two hybrid system to identify proteins that help mouse CD1d transportation in the cytosol. We found that two proteins, heat shock protein a sub-unit $(Hsp90{\alpha})$ and protein kinase C and casein kinase substrate in neurons 3 (PACSIN-3), interact with CD1d. Future study will be focus on the role of these molecules during the CD1d antigen presentation.

• Parasites, Hosts and Diseases
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• v.31 no.1
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• pp.37-42
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• 1993

Surface proteins of Trichomonqs unginnlis (T vqsinalis) were analyzed to study the antigenic variation. The surface proteins of protozoa were labelled by N- hydrokysuccinimide-biotin (NHS-biotins, the NHS-biotin-labelled proteins were immunoprecipitated with rabbit antiserum to purifjr the antigenic fractions and analysed by SDS-PAGE plus electroblotting. The results obtained in this study were as follows; Biotinylated T. uaginalis-proteins obtained from intact cell and cells disrupted prior to labelling were detected by antibiotin-peroxidase in Western blots. Labelled proteins were immunoprecipitated by T. vcqinalis-immunized rabbit serum and the six bands with, the molecular weights of 46, 60, 68, 90, 130 and 220 kDa were identified as having antigenicity. T unginalis HY-1,HY-15 and ATCC 50148 were immunoprecipitated by immune rabbit serum after biotinylation and there were no difference from antigenic bands among these strains by this tehchnique. In conclusion with the results obtained in the present study, it was assumed that surface proteins of T vaqinclis were labelled by biotinylation and the six labelled bands at 46, 60, 68, 90, 130 and 220 kDa in their molecular weight were identified as having antigenicity by immunoprecipitation (IPI and this biotinylation-IP technique may be used for further study of surface antigen of T vaginalis.

• Microbiology and Biotechnology Letters
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• v.33 no.3
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• pp.189-193
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• 2005

IgE-dependent histamine-releasing factor(HRF) was initially described as a secretagogue for secretion of histamine from IgE+ basophils from a subset of allergic donors. Previously, we identified that S98 residue of HRF was phosphorylated using anti-HRFpS98 antibody which specifically recognizes the phosphorylated serine residue of HRF and HRFS98A mutant construct. In vitro kinase assay, only wild type HRF was phosphorylated by PKC, and S98A HRF was not affected by PKC. In this study, we attempted to characterize the phosphatase which specifically dephosphorylates HRF by immunoprecipitation and pull-down assay. In RBL-2H3 cells, HRF interacted only with calcineurin (also called as PP2B, calcium/calmodulin-dependent phosphatase) but not with PP1 or PP2A. The results suggest that HRF is most likely dephosphory-lated by calcineurin.

• Korean Journal of Veterinary Research
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• v.32 no.1
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• pp.83-90
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• 1992

Monoclonal antibodies against structural proteins of bovine viral diarrhea virus(BVDV) were derived by classical hybridoma techniques. These antibodies were characterized by serum neutralization, immunoblotting and immunoprecipitation. The neutralizing monoclonal antibody reacted with the 56kd to 54kd(M.W.) viral protein in western blotting and immunoprecipitation analysis. Although there was no neutralizing activity, another monoclanal antibody reacted with the 45kd protein by immunoprecipitation and with both the 45kd and 36kd proteins in immunoblotting analysis. respectively. Densitometer scanning of purified BVDV and the immunopreipitation of whole virus particles with neutralizing monoclonal antibody revealed the presence of more than twelve viral polypeptides. Although no possible precursor form of protein was identified with the neutralizing monoclonal antibody. the presence of intact virion was detected in the infected cell supernatant immediatelty after pulse labeling, indicating rapid translational processing as well as packaging of the virus. The partial peptide mapping of 45kd and 36kd proteins with Staphylococcus aureus V 8 protease showed that these two proteins are related.

• Journal of Microbiology and Biotechnology
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• v.32 no.7
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• pp.938-948
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• 2022

Gastric cancers (GC) are generally malignant tumors, occurring with high incidence and threatening public health around the world. Circular RNAs (circRNAs) play crucial roles in modulating various cancers, including GC. However, the functions of circRNAs and their regulatory mechanism in colorectal cancer (CRC) remain largely unknown. This study focuses on both the role of circCOL1A2 in CRC progression as well as its downstream molecular mechanism. Quantitative polymerase chain reaction (qPCR) and western blot were adopted for gene expression analysis. Functional experiments were performed to study the biological functions. Fluorescence in situ hybridization (FISH) and subcellular fraction assays were employed to detect the subcellular distribution. Luciferase reporter, RNA-binding protein immunoprecipitation (RIP), co-immunoprecipitation (Co-IP), RNA pull-down, and immunofluorescence (IF) and immunoprecipitation (IP) assays were used to explore the underlying mechanisms. Our results found circCOL1A2 to be not only upregulated in GC cells, but that it also propels the migration and invasion of GC cells. CircCOL1A2 functions as a competing endogenous RNA (ceRNA) by sequestering microRNA-1286 (miR-1286) to modulate ubiquitin-specific peptidase 10 (USP10), which in turn spurs the migration and invasion of GC cells by regulating RFC2. In sum, CircCOL1A2 sponges miR-1286 to promote cell invasion and migration of GC by elevating the expression of USP10 to downregulate the level of RFC2 ubiquitination. Our study offers a potential novel target for the early diagnosis and treatment of GC.

• Bulletin of the Korean Chemical Society
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• v.33 no.5
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• pp.1765-1768
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• 2012