• Journal of Microbiology and Biotechnology
• /
• v.12 no.5
• /
• pp.826-828
• /
• 2002

In our previous studies, we have cloned and characterized a gene region from Bradyrhizobium japonicum ,which is involved in the synthesis of lipopolysaccharide (LPS). In this study, we have expanded the sequence analysis of the region and found an additional open reading frame (orf), which appeared to be divergently transcribed from the rfaF gene. Sequence alignment of the orf revealed a significant similarity with rfaD genes of Salmonella typhimurium , Escherichia coli, and Neisseria gonorrhoeae. These genes encode a heptose-6-epimerase, which catalyzes the interconversion of ADP -D -glycerol-D-manno-heptose to ADP-L-glycero-D-manno-heptose. This divergent organization of the rfaF and rfaD genes is different from that of other Gram-negative bacteria where two genes form an operon. A rfaD- mutant of E. coli was successfully transformed with plasmid constructs containing the rfaD gene of B. japonicum. Novobiocin sensitivity test showed that the rfaD gene from B. japonicum could complement the rfaD mutation in E. coli, which confirms the functionality of the cloned B. japonicum gene.

• Journal of The Korean Society of Inherited Metabolic disease
• /
• v.13 no.2
• /
• pp.126-130
• /
• 2013

Galactosemia is a metabolic disorder inherited by the recessive autosome, and appears by the deficiency of one enzyme out of GALT (Galactose-1-Phosphate Uridyltransferase), GALK (galactokinase), and GALE (epimerase) enzymes, among which the GALT deficiency disease is denominated as classical galactosemia and known to have symptoms such as severe nausea, jaundice, hepatomegaly, sucking difficulty and so on. We report the case of a 16-day-old female baby with the new p.A101D mutation together with p.N413d in the GALT gene analysis found in the neonatal screening test and diagnosed to have galactosemia by the GALT deficiency through the enzyme analysis. For the prognosis prediction, the treatment, the genetic counseling and the prenatal diagnosis of the patients, more detailed genetic diagnosis is required by performing GALT gene analysis, and it is deemed to be necessary to analyze the correlation between the phenotype and the genotype of the domestic galactosemia patients.

• Journal of The Korean Society of Inherited Metabolic disease
• /
• v.13 no.2
• /
• pp.89-97
• /
• 2013

Purpose: We retrospectively investigated individuals who hadbeen identified by neonatal screening as potential galactosemia patients to determine the etiology of galactosemia. Methods: One hundred fifty-three patients referred to Korea Genetics Research Center due to high galactose level detected by neonatal screening test between February 2005 and May 2013 were examined. Galactose and galactose-1-phosphate levels were measured by using a fluoro metric microplate reader. Lactose free diet was initiated immediately after confirmed by urine Clinitest. If reducing sugar was negative, we employed abdominal sonogram and echocardiogram to check for possible porto-systemic shunt. Results: Fifteen patients were diagnosed with galactosemia. One patient had galactokinase (GALK) deficiency; four had UDP galactose-4-epimerase (GALE) deficiency; two had citrin deficiency; and four had porto-systemic shunt. Two had unknown causes of galactosemia. Conclusion: In addition to genetic defects of GALT, GALK and GALE, citrin deficiency or porto-systemic shunt could also cause galactosemia. It is crucial to carry out differential diagnosis to determine the cause of galactosemia.

• Plant Biotechnology Reports
• /
• v.3 no.1
• /
• pp.95-101
• /
• 2009

Tea leaves are major source of catechins—antioxidant flavonoids. Dihydroflavonol 4-reductase (DFR, EC 1.1.1.219) is one of the important enzymes that catalyzes the reduction of dihydroflavonols to leucoanthocyanins, a key ''late'' step in the biosynthesis of catechins. This manuscript reports characterization of DFR from tea (CsDFR) that comprised 1,413 bp full-length cDNA with ORF of 1,044 bp (115-1,158) and encoding a protein of 347 amino acids. Sequence comparison of CsDFR with earlier reported DFR sequences in a database indicated conservation of 69-87% among amino acid residues. In silico analysis revealed CsDFR to be a membrane-localized protein with a domain (between 16 and 218 amino acids) resembling the NAD-dependent epimerase/dehydratase family. The theoretical molecular weight and isoelectric point of the deduced amino sequence of CsDFR were 38.67 kDa and 6.22, respectively. Upon expression of CsDFR in E. coli, recombinant protein was found to be functional and showed specific activity of 42.85 nmol $min^{-1}$ mg $protein^{-1}$. Expression of CsDFR was maximum in younger rather than older leaves. Expression was down-regulated in response to drought stress and abscisic acid, unaffected by gibberellic acid treatment, but up-regulated in response to wounding, with concomitant modulation of catechins content. This is the first report of functionality of recombinant CsDFR and its expression in tea.

• Journal of Microbiology and Biotechnology
• /
• v.13 no.3
• /
• pp.451-456
• /
• 2003

An expression vector system was developed for the secretory production of recombinant Bacillus stearothermophilus L1 lipase in Saccharomyces cerevisiae. The mature L1 lipase gene was fused to ${\alpha}-amylase$ signal sequence from Aspergillus oryzae for the effective secretion into the culture broth and the expression was controlled under GAL10 (the gene coding UDP-galactose epimerase of S. cerevisiae) promoter. S. cerevisiae harboring the resulting plasmid successfully secreted L1 lipase into the culture broth. To examine an optimum condition for L1 lipase expression in the fed-batch culture, L1 lipase expression was induced at three different growth phases (early, mid, and late-exponential growth phases). Maximum product on of L1 lipase (1,254,000 U/l, corresponding to 0.65/1) was found when the culture was induced at an early growth phase. Secreted recombinant L1 lipase was purified only through CM-Sepharose chromatography, and the purified enzyme showed 1,963 U/mg of specific activity and thermoalkalophilic properties similar to those reported for the enzyme expressed in Escherichia coli.

• 한국생물공학회:학술대회논문집
• /
• 2000.11a
• /
• pp.660-664
• /
• 2000

To clone genes related UK-58,852 production, genomic DNA of strain Actinodura roseorufa was used for the construction of genomic library using pOJ446 cosmid vector. The genomic library was screened rising dehydratase PCR product and eryA gene as a DNA hybridization probe. pHD54 was isolated, which contained an approximately 35kb of inserted DNA. BamHI, SmaI and sonicater fragments hybridized to eryA probe. All of pHD54 BgmHI, SmaI and sonicater fragments were subcloned into pGEM7 and some fragments which hybridized to eryA probe were sequenced. The nucleotide sequence was analysed using BLAST program. The sequence identities were observed in KS,AT, KR, ER and PKS loading domains. Also oxidoreductase showed similarity to rifamycin module10, and dTDP-D-glucose 4,6 dehydratase and TDP-D-glucose synthase involved in biosynthesis of sugar showed similarity to Streptomyces argillaceus.

• Journal of Microbiology and Biotechnology
• /
• v.18 no.1
• /
• pp.88-94
• /
• 2008

Two sugar biosynthetic cassette plasm ids were used to direct the biosynthesis of a deoxyaminosugar. The pOTBP1 plasmid containing TDP-glucose synthase (desIII), TDP-glucose-4,6-dehydratase (desIV), and glycosyltransferase (desVII/desVIII) was constructed and transformed into S. venezuelae YJ003, a strain in which the entire gene cluster of desosamine biosynthesis is deleted. The expression plasmid pOTBP3 containing 4-aminotransferase (gerB) and 3,5-epimerase (orf9) was transformed again into S. venezuelae YJ003-OTBP1 to obtain S. venezuelae YJ003-OTBP3 for the production of 4-amino-4,6-dideoxy-L-glucose derivatives. The crude extracts obtained from S. venezuelae ATCC 15439, S. venezuelae YJ003, and S. venezuelae YJ003-OTBP3 were further analyzed by TLC, bioassay, HPLC, ESI/MS, LC/MS, and MS/MS. The results of our study clearly shows that S. venezuelae YJ003-OTBP3 constructs other new hybrid macrolide derivatives including 4-amino-4,6-dideoxy-L-glycosylated YC-17 (3, [M+ $Na^+$] m/z=464.5), methymycin (4, m/z=480.5), novamethymycin (6, m/z=496.5), and pikromycin (5, m/z=536.5) from a 12-membered ring aglycon (10-deoxymethynolide, 1) and a 14-membered ring aglycon (narbonolide, 2). These results suggest a successful engineering of a deoxysugar pathway to generate novel hybrid macrolide derivatives, including deoxyaminosugar.

• Natural Product Sciences
• /
• v.23 no.1
• /
• pp.35-39
• /
• 2017

D-chiro-inositol (DCI) is a secondary messenger in insulin signal transduction. It is produced in vivo from myo-inositol via action of epimerase. In this study, we evaluated antitumor activity of DCI against human breast cancer both in vitro and in vivo. In order to determine the inhibitory effects of DCI on growth of human breast cancer cells (MDA-MB-231), two different assessment methods were implemented: MTT assay and mouse xenograft assay. MTT assay demonstrated downturn in cell proliferation by DCI treatment (1, 5, 10, 20 and 40 mM) groups by 18.3% (p < 0.05), 17.2% (p < 0.05), 17.5% (p < 0.05), 18.4% (p < 0.05), and 24.9% (p < 0.01), respectively. Also, inhibition of tumor growth was investigated in mouse xenograft model. DCI was administered orally at the dose of 500 mg/kg and 1000 mg/kg body weight to treat nude mouse for 45 consecutive days. On the 45th day, tumor growth of DCI (500 mg/kg and 1000 mg/kg) groups was suppressed by 22.1% and 67.6% as mean tumor volumes were $9313.8{\pm}474.1mm^3$ and $3879.1{\pm}1044.1mm^3$, respectively. Furthermore, breast cancer stem cell (CSC) phenotype ($CD44^+/C24^-$) was measured using flow cytometry. On the 46th day, CSC ratios of DCI (500 mg/kg) and co-treatment with doxorubicin (4 mg/kg) and DCI (500 mg/kg) group decreased by 24.7% and 53.9% (p < 0.01), respectively. Finally, from tumor recurrence assay, delay of 5 days in the co-treatment group compared to doxorubicin (4 mg/kg) alone group was observed. Based on these findings, we propose that DCI holds potential as an anti-cancer drug for treatment of breast cancer.

• Neonatal Medicine
• /
• v.17 no.1
• /
• pp.136-140
• /
• 2010

Galactosemia is a group of inherited enzyme deficiencies characterized by increase in the blood galactose levels. This condition may be associated with deficiencies of galactose-1-phosphate uridyl transferase, galactokinase, or uridine diphosphate galactose-4-epimerase. However, the elevated galactose identified by neonatal screening tests has several other possible etiologies, including hepatic hemangioendothelioma, hepatic hemangioma, and patent ductus venosus with hypoplasia of the portal vein. We report a 13-day-old Korean male with hepatic hemangioendothelioma, which was incidentally detected during the evaluation for suspected galactosemia. Laboratory studies revealed that mildly elevated levels of galactose, galactose-1-phosphate and alpha- fetoprotein, at the time of admission, were graduallydecreased to the normal range over the 6 months of observation. Ultrasonography showed a well-defined heterogeneous hypoechoic mass in the liver, and magnetic resonance imaging study showed multiple enhanced mass lesions, which was compatible with the diagnosis of a hepatic hemangioendothelioma. Thus, hepatic imaging, especially ultrasonography, should be performed if neonatal screening suggests galactosemia.

• Journal of Applied Biological Chemistry
• /
• v.58 no.3
• /
• pp.227-232
• /
• 2015

A microarray study has been employed to understand changes of gene expression in E. coli KD43162 resistant to ampicillin, ampicillin-sulbactam, piperacillin, piperacillin-tazobactam, cefazolin, cefepime, aztreonam, imipenem, meropenem, gentamicin, tobramycin, ciprofloxacin, levofloxacin, moxifloxacin, fosfomycin, and trimethoprim-sulfamethoxazole except for amikacin using disk diffusion assay. Using Sodium dodecyl sulphate-polyacrylamide gel electrophoresis and MALDI-TOF MS analyses, 36 kDa of outer membrane proteins (OMPs) was found to be deleted in the multidrug resistant E. coli KD 43162. Microarray analysis was used to determine up- and down-regulated genes in relation to multidrug resistant E. coli KD43162. Among the up-regulated genes, these genes were corresponded to express the proteins as penicillin-binding proteins (PBPs), tartronate semialdehyde reductase, ethanolamine utilization protein, shikimate kinase I, allantoinase, predicted SAM-dependent methyltransferase, L-glutamine: D-fructose-6-phosphate aminotransferase (GFAT), phospho-glucosamine mutase, predicted N-acetylmannosamine kinase, and predicted N-acetylmannosamine-6-P epimerase. Up-regulation of PBPs, one of primary target sites of antibiotics, might be responsible for the multidrug resistance in E. coli with increasing amount of target sites. Up-regulation of GFAT enzyme may be related to the up-regulation of PBPs because GFAT produces N-acetylglucosamine, a precursor of peptidoglycans. One of GFAT inhibitors, azaserine, showed a potent inhibition on the growth of E. coli KD43162. In conclusion, up-regulation of PBPs and GFATs with the loss of 36 kDa OMP refers the multidrug resistance in E. coli KD 43162.