• Journal of the Korean Vacuum Society
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• v.17 no.6
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• pp.549-554
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• 2008

Nickel Chloride coated protein chip plates were developed by using a spin coating method after $H_2$ plasma treatment. The adsorption ability of histidine tagged protein was investigated at various times of plasma treatment. The properties of the nickel chloride and protein on the surface of the slides were assayed using particle size analysis and the extent of the protein adsorption was determined by using a bio imaging analyzer system. The results show that the ability of protein adsorption decreased as increasing the time of $H_2$ plasma treatment. The mechanism on the ability of protein adsorption at the plate surface is discussed on results and discussions. The results also suggest that the surface stabilization of protein chip plates treated by plasma technology may be applicable in biosensor markets.

• Journal of the Korean institute of surface engineering
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• v.37 no.2
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• pp.76-79
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• 2004

Nickel chloride coated protein chip plate was developed by using a spin coating method. The ability of histidine tagged protein adsorption was investigated at various solvents. The surface of plate has a large aggregated nickel complex with high density in water. However, the surface of plate has a very small size of aggregated nickel complex with low density in isopropanol. The ability of protein adsorption decreased as increasing the size of alkyl chain in various alcohol solvents. The mechanism on the ability of protein adsorption at the plate surface is discussed.

• Journal of the Korean institute of surface engineering
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• v.40 no.2
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• pp.98-102
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• 2007

[ $NiCl_2$ ] and poly-L-lysine coated protein chip plates have been fabricated using a spin coating system. Water has been used as solvent and scratching effects on glass slides and ITO have been investigated. We also observed the surface properties of $NiCl_2$ and poly-L-lysine coated slides by using PSA(Particle size analyzer) and AFM(Atomic force microscope). The AFM results imply that the surface patterns created in the spin coating system determine the protein adsorption. Adsorption of histidine-tagged KRS proteins immobilized on glass slides and ITO was analyzed using a BAS image system. The results suggest that the scratching effect was increased ability of protein adsorption.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.554-556
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• 2003

This research was focused on expression, purification and characterization of ubiquitin-specific protease 1 (UBP1) expressed in recombinant Escherichia coli. Various systems were constructed by fusing polycationic fusion tails or fusion partners to the C- or N-terminus of the product protein. In particular, UBP1 containing 6 histidine residues at the N-terminal end showed best results in terms of expression level and purification efficiency. The N-terminal $6{\times}His-tagged$ UBP1 was overproduced in recombinant E. coli using high cell density cultivation technology and purified using immobilized metal affinity chromatography. The molecular weight of UBP1 was found to be 83,500 daltons. The optimum temperature and pH for the enzyme reaction when ubiquitin-human growth hormone (hGH) was used as a substrate were $40^{\circ}C$ and pH 8.0, respectively.

• Journal of Life Science
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• v.15 no.3 s.70
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• pp.415-422
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• 2005

library of the mutants was prepared by transposon mutagenesis of the Mycobacterium bovis BCG. We screened this library for the resistance to an anti-tuberculosis antibiotic, PA-824. Most of the mutants resistant to the PA-824 were not able to synthesize the coenzyme $F_{420}$ which is normally produced by the wild type M. bovis BCG strains. HPLC analysis of the cellular extract showed that one of those mutants which lost the ability to synthesize $F_{420}$ still produced F0. The insertion site of the transposon in this mutant was determined by an inverse PCR and the transposon was found to be inserted in the Rv2435c open reading frame (ORF). Rv2435c ORF is predicted to encode an 80.3 kDa protein. Rv2435c protein appears to be bound to the cytoplasmic membrane, its N-terminal present in the periplasm and C-terminal in the cytoplasm. The C-terminal portion of this protein is highly homologous with the adenylyl cyclases of both prokaryotes and eukaryotes. There are 15 ORFs which have homology with the class III AC proteins in the genome of the M. tuberculosis and M. bovis. Two of those, Rv1625c and Rv2435c, are highly homologous with the mammalian ACs. We cloned the cytoplasmic domain of the Rv2435c ORF and expressed it with six histidine residues attached on its C-terminal in Escherichia coli to find out if this protein is a genuine AC. Production of that protein in E. coli was proved by purifying the histidine-tagged protein by using the Ni-NTA resin. This protein, however, failed to complement the cya mutation in E. coli, indicating that this protein lacks the AC activity. All of the further attempts to convert this protein to a functional AC by a mutagenesis with UV or hydroxylamine, or construction of several different fusion proteins with Rv1625c failed. It is, therefore, possible that Rv2435c protein might affect the conversion of F0 to $F_{420}$ not by synthesizing cAMP but by some other way.

• Biomolecules & Therapeutics
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• v.9 no.2
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• pp.79-87
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• 2001

Heat shock proteins serve as chaperone by preventing the aggregation of denatured proteins and promote survival of pathogens in harsh environments. In this study, heat shock gene encoding a 84-kDa (p84) protein, which is one of the three major heat shock proteins in S. pneumoniae, was cloned and characterized. PCR with a forward primer derived from N-terminal amino acid sequence of the p84 and a reverse primer derived from the conserved second ATP-binding region of Clp family was used for amplification of the gene encoding the p84 and subsequently the PCR product was used for sequence determination. Sequence analysis of the p84 gene demonstrated that it is a member of ClpL. The deduced amino acid sequence of pneumococcal ClpL shows homology with other members of the Clp family, and particularly, even in variable leader region, with bovine Clp-like protein and L. lactis ClpL. S. pneumoniae clpL is the smallest clop member (701 amono acids) containing the two conserved ATP-binding regions, and hydrophilic N-terminal variable region of pneu-mococcal Clp ATPase is much shorter than any known Clp ATPases. Histidine tagged ClpL was overexpressed and purified from E. coli. Immunoblot analysis employing antisera raised against pneumococcus p84 demonstrated no cross-reactivity with Clp analog in Eschericha coli, Staphylococcus aureus and human HeLa cells. Preimmunization of mice with ClpL extended mice life partially but did not protect them from death.

• Korean Journal of Microbiology
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• v.42 no.1
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• pp.1-6
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• 2006

Saccharomyces cerevisiae Dna2 helicase/endonuclease plays an essential role in removing DNA primers during Okazaki fragment processing in eukaryotic DNA replication. Genome-wide scale co-immunoprecipitation experiments predicted that Dna2 interacts with a novel protein YHR122W (1). In this study, we observed that overexpression of YHR122W gene suppressed the temperature-sensitive phenotype of $dna2\Delta405N$ mutation. To investigate direct interaction between these two proteins, a histidine-tagged recombinant YHR122W protein was expressed and purified from E. coli. Physical interaction between the purified YHR122W and Dna2 proteins was detected by enzyme-linked immunosorbent assays. Further more, the complex formation was most efficient at physiological salt concentration, 150 mM NaCl. The genetic and physical interactions between YHR122W and Dna2 shown in this study suggest that the biological functions of these two proteins may be closely related each other.