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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal DOI :
Korean Society for Biochemistry and Molecular Biology
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Volume & Issues
Volume 33, Issue 6 - Nov 2000
Volume 33, Issue 5 - Sep 2000
Volume 33, Issue 4 - Jul 2000
Volume 33, Issue 3 - May 2000
Volume 33, Issue 2 - Mar 2000
Volume 33, Issue 1 - Jan 2000
Selecting the target year
Duggleby, Ronald G. ; Pang, Siew Siew ;
BMB Reports , volume 33, issue 1, 2000, Pages 1~36
Acetohydroxyacid synthase (EC 184.108.40.206) catalyses the first reaction in the pathway for synthesis of the branched-chain amino acids. The enzyme is inhibited by several commercial herbicides and has been subjected to detailed study over the last 20 to 30 years. Here we review the progress that has been made in understanding its structure, regulation, mechanism, and inhibition.
Laccase of Lentinus edodes Catalyzed Oxidation of Amines and Phenolic Compounds: A Semiempirical Quantum Chemical Consideration
Pankratov, Alexei N. ; Tsivileva, Olga M. ; Nikitina, Valentina E. ;
BMB Reports , volume 33, issue 1, 2000, Pages 37~42
Based on the study by Leatham and Stabmann concerned with the rates (v) of amines and phenolic compounds oxidation catalyzed by laccase of basidiomycete Lentinus edodes (Berk.) Sing., as well as on the results of semiempirical quantum chemical computations using the PM3 method, the linear correlations of v and lnv values with first vertical ionization potentials of the substrates molecules and radicals derived from them, spin densities on N and O atoms of the above radicals, and with the radicals reorganization energies have been found.
Structural Arrangement for Functional Requirements of Brain Recombinant 4-Aminobutyrate Aminotransferase
Sung, Bo-Kyung ; Kim, Young-Tae ;
BMB Reports , volume 33, issue 1, 2000, Pages 43~48
4-Aminobutyrate aminotransferase is a key enzyme of the 4-aminobutyric acid shunt. It converts the neurotransmitter 4-aminobutyric acid to succinic semialdehyde. In order to study the structural and functional aspects of catalytically active Cys residues of pig brain 4-aminobutyrate aminotransferase, we purified the active form in E. coli by coproduction of thioredoxin. The structural arrangement for functional requirements of a dimeric protein using a bifunctional sultbydryl reagent was then characterized, and the spatial proximity between the essential SH groups and a cofactor (pyridoxal-5'-phosphate) binding site was determined. The bifunctional sultbydryl reagent DMDS reacted with the enzyme at the ratio of one molecule per enzyme dimer. This resulted in an approximately 50% loss of enzymatic activity. The spatial proximity of the distance between the essential SH groups and the cofactor-binding site was determined by the energy transfer measurement technique. The result (approximate 20
) suggested that cross-linking of two sulfhydryl groups with DMDS is not near a PLP binding site.
Structure and Antibiotic Activity of a Porcine Myeloid Antibacterial Peptide, PMAP-23 and its Analogues
Shin, Song-Yub ; Kang, Joo-Hyun ; Jang, So-Yun ; Kim, Kil-Lyong ; Hahm, Kyung-Soo ;
BMB Reports , volume 33, issue 1, 2000, Pages 49~53
PMAP-23 is a 23-residue antimicrobial peptide derived from porcine myloid cells. In order to investigate the effects of two Pro residues at positions 12 and 15 of PMAP-23 on antibiotic activity, two analogues in which Ala was substituted for Pro residue at position 12 or 15 were synthesized.
(PMAP2) substitution in PMAP-23 caused a significant reduction on antitumor and phospholipid vesicle-disrupting activities, but did not cause a significant effect on antibacterial activity. PMAP-23 displayed the type I
structure with a negative ellipticity at near 205 om in SDS micelle, whereas PMAP1 and PMAP2 had a somewhat
propensity in TFE solution, as compared to PMAP-23. These results suggest that two Pro residues of positions 12 and 15 in PMAP-23 play important roles in the formation of
structure on lipid membrane and its
structure may be essential for antibiotic activity including phospholipid vesicle-disrupting property.
Molecular Dynamic Simulations of the Fatty Acid Bilayer Containing Very Long Chain Transmembrane Dicarboxylic Acids
Choi, Yong-Hoon ; Yang, Chul-Hak ; Kim, Hyun-Won ; Jung, Seun-Ho ;
BMB Reports , volume 33, issue 1, 2000, Pages 54~58
Recent research results regarding the very long chain transmembrane
components in the membrane of extremophilic eubacteria, such as Sarcina ventriculi, Thennotoga maritima, and Thermoanaerobacter ethanolicus have raised interesting questions concerning the physical and biochemical function on these components in the membrane. In order to understand the dynamic characteristics of these acids which reside in the bilayer membrane, 580 ps molecular dynamic simulations at 300 K were performed for two model systems. These systems were the bilayer with regular chain (C16:0 or C18:1) fatty acid methyl esters and the fatty acid bilayer containing very long chain transmembrane dicarboxylic acid methyl esters (
dimethyl ester; C32:0). Our analyses indicate that very long chain transmembrane dicarboxylic acids have a noticeable influence on the bilayer dynamics at a sub-nanosecond time scale. The center-ofmass mean-squared-displacement (MSD) of regular chain fatty acids adjacent to the very long chain transmembrane dicarboxylic acids decreased, the long-axis order parameter increased, and the reorientational motions of methylene groups were slowed along the hydrocarbon chains. These results indicate that the very long chain transmembrane dicarboxylic acids reduce the molecular order of the whole bilayer membrane.
Identification of a Cellular Protein Interacting with RNA Polymerase of Hepatitis C Virus
Park, Kyu-Jin ; Choi, Soo-Ho ; Koh, Moon-Soo ; Kim, Sung-Wan ; Hwang, Soon-Bong ;
BMB Reports , volume 33, issue 1, 2000, Pages 59~62
Hepatitis C virus (HCV) nonstructural 5B (NS5B) protein is an RNA-dependent RNA polymerase (RdRp). To determine whether it can contribute to viral replication by interaction with cellular proteins, the yeast two-hybrid screening system was employed to screen a human liver cDNA library. Using the HCV NS5B as a bait, we have isolated positive clones encoding a cellular protein. The NS5B interacting protein, 5BIP, is a novel cellular protein of 170 amino acids. Interaction of the HCV NS5B protein with 5BIP was confirmed by a protein-protein blotting assay. Recently, we have demonstrated that NS5B possesses an RdRp activity and thus it is possible that 5BIP, in association with NS5B, plays a role in HCV replication.
Ecdysteroid Stimulates Virus Transmission in Larvae Infected with Bombyx mori Nucleopolyhedrovirus
Kang, Kyung-Don ; Lee, Eun-Jung ; Kamita, Shizuo George ; Maeda, Susumu ; Seong, Su-Il ;
BMB Reports , volume 33, issue 1, 2000, Pages 63~68
Most baculoviruses have an ecdysteroid UDP-glucosyltransferase (egt) gene, whose product inactivates ecdysteroid within the infected host. Bomhyx mori larvae infected with BmEGTZ, a mutant B. mori nucleopolyhedrovirus (BmNPV) in which the egt gene has been inactivated, die more rapidly compared to larvae infected with wild-type BmNPV. In this study, the profile of hemolymph proteins, and progression of virus infection in BmEGTZ- and BmNPV-infected B. mori larvae, was analyzed by SDS-PAGE and histochemically. These analyses showed that virus-encoded and virus-induced proteins were expressed quicker in BmEGTZ-infected larvae than in BmNPV-infected larvae. This suggests that the decrease in time to death, following BmEGTZ infection, results from the stimulation of virus-specific protein expression. In order to examine the effect of ecdysteroid on virus transmission, the profile of hemolymph proteins, and progression of virus infection, were analyzed following an ecdysteroid injection of BmEGTZ- or BmNPV-infected larvae. In the BmNPV-infected larvae, ecdysteroid treatment had no apparent effect on hemolymph protein expression. This suggests that the injected ecdysteroid was inactivated by the BmNPV-expressed ecdysteroid UDP-glucosyltransferase. An Ecdysteroid injection into BmEGTZ-infected larvae increased the speed of virus-specific protein expression and virus transmission. These results suggest that ecdysteroid stimulates protein expression, which in tum results in the stimulation of virus transmission.
Studies on the active site of the Arabidopsis thaliana S-Adenosylmethionine Decarboxylase:
residue involvement in catalytic activity
Park, Sung-Joon ; Cho, Young-Dong ;
BMB Reports , volume 33, issue 1, 2000, Pages 69~74
The Arabidopsis thaliana S-Adenosylmethionine decarboxylase (AdoMetDC) cDNA (
U63633) was cloned, then the AdoMetDC protein was expressed and purified. The purified AdoMetDC was inactivated by salicylaldehyde in a pseudo first- order kinetics. The secondorder rate constant for inactivation was 126
with the slope of n=0.73, suggesting that inactivation is the result of the reaction of one lysine residue in the active site of AdoMetDC. Site-specific mutagenesis was performed on the AdoMetDC to introduce mutations in conserved
residues. These were chosen by examination of the conserved sequence and proved to be involved in enzymatic activity by chemical modification. Changing
to alanine showed an altered optimal pH. The substrate also provided protection against inactivation by salicylaldehyde. Considering these results, we suggest that the
residue may be involved in catalytic activity.
Characterization of dnaK Mutants in Streptococcus pneumoniae
Kim, Seung-Whan ; Pyo, Suhk-Neung ; Rhee, Dong-Kwon ;
BMB Reports , volume 33, issue 1, 2000, Pages 75~81
DnaK is a major heat shock protein and known to be highly conserved in all species. Previously, the dnaK in Streptococcus pneumoniae was cloned and the immunogenic nature characterized. In this study, dnaK mutants were generated by insertion of duplication mutagenesis and their characteristics examined. They had defective growths at all temperatures (
)and cell divisions, and formed filaments after a temperature shift from 30 to 42. A unique feature of the dnaK mutants of S. pneumoniae, unlike those of E. coli and B. subtilis, was the growth capability at high temperature (
) without producing the putative GroEL. Our results suggest that DnaK may serve as a regulator and/or modifier in GroEL gene expression.
Molecular Cloning of an Extremely Thermostable Alanine Racemase from Aquifex pyrophilus and Enzymatic Characterization of the Expressed Protein
Kim, Sang-Suk ; Yu, Yeon-Gyu ;
BMB Reports , volume 33, issue 1, 2000, Pages 82~88
A homologous gene to alanine racemase was cloned from a hyperthermophilic bacterium, Aquifex pyrophilus. The cloned gene encodes a protein of 341 amino acids, which has a significant homology to alanine racemase of Bacillus stearothermophilus, Lactobacillus brevis, and E. coli. When the gene was expressed in Escherichia coli, it produced a 40 kDa protein. The purified protein contains one mole pyridoxal 5-phosphate per one mole of protein, which is essential for catalytic activity of alanine racemase. The purified protein catalyzed racemization of L-alanine to D-alanine, or vice versa, indicating that the cloned gene encoded alanine racemase. It also showed significant racemization activity against L-serine and
acid. The A. pyrophilus alanine racemase showed strong thermostability, and it maintained catalytic activity in the presence of organic solvents.
Leucine Rich Repeat Sequence of the
Endotoxin Family of Bacillus thuringiensis
Vudayagiri, Suvarchala ; Jamil, Kaiser ;
BMB Reports , volume 33, issue 1, 2000, Pages 89~91
In this investigation we report our search for the presence of Leucine Rich Repeats (LRRs) in various Bacillus thuringiensis (Bt) sub species. Leucine rich repeats are short sequence motifs present in some proteins. The consensus sequence corresponding to the LRR was present in Crystal proteins of Bacillus thuringiensis sub species. This LRR sequence has been predicted to be involved in proteinprotein interactions or receptor binding functions, hence the importance of this study.
Characterization of KI-24, a Novel Murine Monoclonal Antibody with Specific Reactivity for the Human Immunodeficiency Virus-1 p24 Protein
Shin, Song-Yub ; Park, Jung-Hyun ; Lee, Myung-Kyu ; Jang, So-Youn ; Hahm, Kyung-Soo ;
BMB Reports , volume 33, issue 1, 2000, Pages 92~95
The HIV-1 p24(202-221) sequence ETINNEEEWDRVHPV HAGP contains a B-cell epitope with the earliest immune response and the highest antibody titer against anti-mouse sera obtained by immunization with p24 antigens. A novel mouse monoclonal antibody (mAb) was generated against the immunodominant B-cell epitope of the HIV-1 p24 capsid protein, p24(202-221). BALB/c mice were immunized with the four branched multiple antigenic peptide (MAP) containing the HIV-1p24(202-221) sequence, and antibody-secreting hybridoma were produced by fusion of mouse splenocytes with P3X63Ag8.653, mouse myeloma cells. One clone which produced the antigen-specific mAb named KI-24 (Isotype IgG1, light chain:
) was identified. mAb KI-24 was highly specific for both the p24(202-221) and p24 proteins when analyzed by ELISA and Western blotting. Since p24(202-221) also contains a cytotoxic T-lymphocyte epitope, this specfic peptide epitope and the monoclonal antibody with specific reactivity against the p24 protein and p24(202-221) can be used in peptide vaccine development and p24 antigen detection from HIV patients.