• Title, Summary, Keyword: 249ser

Search Result 6, Processing Time 0.027 seconds

Effects of R100 Mutant MerR on Regulation of mer Operon from Shigella flexneri

  • Yoon, Kyung-Pyo
    • Journal of Microbiology and Biotechnology
    • /
    • v.4 no.4
    • /
    • pp.245-249
    • /
    • 1994
  • An amino-terminal 14 amino acids deletion and three site-directed mutations were created to investigate the mechanism of induction and repression of MerR regulatory protein in R100 mer operon from gramnegative Shigella flexneri. The amino-terminal 14 amino acids deletion, Cysl17Ser, and Cys126Ser mutations abolished the inducibility of the mer operon and the Hisl18Ala mutation resulted in the reduction of inducibility (about 9.1 % remaining) in complementation experiment in the presence of $Hg^{2+}$ at subtoxic level ($1\mu M$). The complementation experiment with $Hg^{2+}$ absent showed that Hisl18Ala, Cys126Ser, and wild-type MerR could repress the operon but Cysl17Ser could not, and the amino-terminal deletion mutant could neither induce nor repress the R100 mer operon.

  • PDF

Purification and Characterization of the Anabolic Acetolactate Synthase III from Serratia marcescens ATCC 25419

  • Joo, Han-Seung;Kim, Soung-Soo
    • BMB Reports
    • /
    • v.34 no.3
    • /
    • pp.244-249
    • /
    • 2001
  • The anabolic acetolactate synthase III was purified to homogeneity from Serratia marcescens using DEAE-Sepharose, Phenyl-Sepharose, and hydroxylapatite column chromatography The native molecular weight of the enzyme was approximately 165 kDa. The enzyme is composed of two large and two small subunits with molecular weights of 64 and 15 kDa, respectively. The N-terminal sequence of the large and small subunit of the enzyme was Ser-Ala-Thr-Pro-Gln-Pro-Ser-Thr-Arg-Phe-Thr-Cys-Ala-Gln-Leu-Ile-Ala-His-Leu and Met-Leu-Gln-Pro-Gln-Asp-Lys-Pro-Gln-Val-Ile-Leu-Glu-Leu-Ala-Val-Arg-Asn-His-Pro-Gly-Val-Met-Ser-His-Val, respectively. The optimum pH and pI value were 7.5 and 5.5, respectively The $IC_{50}$ values were $20\;{\mu}M$ and $14\;{\mu}M$ for valine and herbicide SU7, respectively. The substrate specificity ratio, R value, was determined to be approximately 40, which suggests that this enzyme prefers the formation of $\alpha$-aceto-$\alpha$-hydroxybutyrate leading to the synthesis of isoleucine.

  • PDF

Effects on Phase Noise of QSPK, MQAM, OFDM-QPSK, OFDM-MQAM, and 8-VSB Modulations (QPSK, MQAM, OFDM-QPSK, OFDM-MQAM 및 8-VSB 변조방식에 대한 위상잡음의 영향)

  • Kwon, Joh-Ann;Kim, Ihn-Seok
    • The Journal of Advanced Navigation Technology
    • /
    • v.10 no.3
    • /
    • pp.235-249
    • /
    • 2006
  • In this paper, SER(Symbol Error Rate) variation and effects on SER by phase noise at various frequency offset of the local oscillator in digital communication systems are gerneralyzed for QPSK(Quadrature Phase Shift Keying), MQAM(M-ary Quadrature Amplitude Modulation), OFDM(Orthogonal Frequency Division Multiplex)-MQAM, OFDM-QPSK and 8-VSB(Vestigal Side Bands) modulation methods and compared those with the ideal cases, which have no phase noise, through the MATLAB simulation. And the ration between modulation bandwidths and the SER on the various frequency offsets on the above modulation methods have been analyzed for the system requirement of minimum phase noise characteristics. From this study, we have confirmed that the most sensitive modulation method on the phase noise is OFDM-MQAM and that the relatively insensitive method 8-VSB.

  • PDF

Prevalence of Aflatoxin Induced p53 Mutation at Codon 249 (R249s) in Hepatocellular Carcinoma Patients with and without Hepatitis B Surface Antigen (HBsAg)

  • Chittmittrapap, Salyavit;Chieochansin, Thaweesak;Chaiteerakij, Roongruedee;Treeprasertsuk, Sombat;Klaikaew, Naruemon;Tangkijvanich, Pisit;Komolmit, Piyawat;Poovorawan, Yong
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.14 no.12
    • /
    • pp.7675-7679
    • /
    • 2013
  • Background: A missense mutation in exon 7 (R249S) of the p53 tumor suppressor gene is characteristic of aflatoxin B1 (AFB1) exposure. AFB1 is believed to have a synergistic effect on hepatitis virus B (HBV) carcinogenesis. However, results of studies comparing R249S prevalence among patients are conflicting. The aim of this study was to determine the prevalence of the R249S mutation in hepatocellular carcinoma (HCC) patients with or without positive HBsAg. Materials and Methods: Paraffin embedded liver tissues were obtained from 124 HCC patients who underwent liver resection and liver biopsy in King Chulalongkorn Memorial Hospital. Restriction fragment length polymorphism (RFLP) was utilized to detect the R249S mutation. Positive results were confirmed by direct sequencing. Results: Sixty four (52%) patients were positive for HBsAg and 18 (15%) were anti-HCV positive. 12 specimens tested positive by RFLP. Ten HCC patients (8.1%) were confirmed to be R249S positive by Sanger sequencing (AGG to AGT). Out of these 10, six were HBsAg positive, and out of the remaining 4, two were anti-HCV positive. The R249S prevalence among HCC patients with positive HBsAg was 9.4% compared to 6.7% for HBsAg negative samples. Patients with the R249S mutation were younger ($55{\pm}10$ vs $60{\pm}13$ year-old) and tended to have a more advanced Edmonson-Steiner grade of HCC, although differences did not reach statistical significance. Conclusions: Our study shows moderate prevalence of aflatoxin B1-related p53 mutation (R249S) in HCC with or without HBsAg. HBsAg positive status was not associated with R249S prevalence.

Cloning and Nucleotide Sequence of a cDNA Encoding the Rat Triosephosphate Isomerase

  • Lee, Kyunglim;Ryu, Jiwon
    • Archives of Pharmacal Research
    • /
    • v.19 no.6
    • /
    • pp.497-501
    • /
    • 1996
  • A gene coding for triosephosphate isomerase (TPI) from a rat skeletal muscle cDNA library was cloned and its nucleotide sequence was determined. The 1, 348-bp cDNA clone contains 24 bp $5^I$ noncoding region, the entire 750 bp coding region corresponding to a protein of 249 amino acids, $547bp 3^I$ noncoding region and part of a poly(A) tail. It also contains a polyadenylation signal, AATAAA, starting from 17 bp upstream of the poly(A) tail. The calculated molecular weight of rat TPI is 27.8 kDa and the net charge is +4. The deduced amino acid sequence from rat TPI CDNA sequence has 93% and 94% homology with that of mouse and human clones, respectively. The amino acids at the residue of Asn12, Lys14, His96, Glu 166, His96, His101, Ala177, Tyr165, Glu13O, Tyr2O9, and Ser212 in catalytic site are completely identical, confirming that the functional residues in TPI proteins are highly conserved throughout evolution. The most profound characteristic of rat TPI enzyme, compared with other TPIs, is that there are five cysteine substitutions at the residue of 21, 27, 159, 195 and 204. A Glu123 instead of Gly was found in rabbit, rhesus, mouse and human sequences. Through the method of RT-PCR, the mRNA transcription level of TPI gene was found to be different among various tissues and was highest in muscle.

  • PDF

Quality Characteristics of Chun Ma (Gastrodiae rhizoma) Beverage Prepared Using Concentrated Extracts (천마추출액 농축 비율을 달리하여 제조한 천마음료의 품질특성)

  • Lee, Su-Won;Moon, Hye-Kyung;Moon, Jae-Nam;Yoon, Won-Jung;Kim, Gwi-Young
    • Korean Journal of Food Preservation
    • /
    • v.17 no.1
    • /
    • pp.58-65
    • /
    • 2010
  • We investigated the effect of Chun ma (Gastrodiae rhizoma) concentrated extract on the quality of mixed beverages. Chun ma beverages prepared using different concentrated extracts were divided into four groups: GCE 5 ($5^{\circ}$ Brix concentrated extracts) GCE 10 ($10^{\circ}$ Brix concentrated extracts) GCE 15 ($15^{\circ}$ Brix concentrated extracts) and GCE 20 ($20^{\circ}$ Brix concentrated extracts). The pH values ranged from a low of 4.37 in GCE 5 to a high of 4.68 in GCE 20. Soluble solid levels in GCE 20 ($19.6^{\circ}$ Brix) were higher than in the other samples. The b (yellowness) scores and the total phenolic contents of all samples increased with increasing extract concentration. The highest total phenolic contents were seen in GCE 20 samples at 232.23 mg%. Samples did not differ markedly in antiradical activity (75.07-76.00% DPPH inhibition). Free sugar levels in GCE 20 samples and organic acid concentrations of GCE 15 samples were higher than those of other preparations. Free amino acid and mineral contents of all samples increased with increasing extract concentration. The levels of free amino acids were in the order Glu > Gly > Ser > Arg > Hylys, and the Glu content was 249.15 ug/100 g for GCE-20 samples and 61 ug/100 g in GCE-5 products. The mineral contents of all samples were in the order K > Na > Mg > Ca. Higher scores for color, flavor, and overall acceptability were found in GCE 5 products compared with other extracts. These results indicate that Chun ma beverage can be prepared in various ways, as commercially desired, with reference to the above characteristics of Chun ma materials.