• Journal of Microbiology
• /
• 제45권6호
• /
• pp.534-540
• /
• 2007

The Streptomyces coelicolor A3(2) genome contains six operons (rrnA to F) for ribosomal RNA synthesis. Transcription from rrnD occurs from four promoters (p1 to p4). We found that transcripts from the p1 and p3 promoters were most abundant in vivo in the early exponential phase. However, at later phases of exponential and stationary growth, transcripts from the p1 promoter decreased drastically, with the p3 and p4 transcripts constituting the major forms. Partially purified RNA polymerase supported transcription from the p3 and p4 promoters, whereas pure reconstituted RNA polymerase with core enzyme (E) and the major vegetative sigma factor ${\sigma}^{HrdB}$ ($E{\cdot}{\sigma}^{HrdB}$) did not. In order to assess any potential requirement for additional factor(s) that allow transcription from the p3 and p4 promoters, we fractionated a partially purified RNA polymerase preparation by denaturing gel filtration chromatography. We found that transcription from the p3 and p4 promoters required factor(s) of about 30-35 kDa in addition to RNAP holoenzyme ($E{\cdot}{\sigma}^{HrdB}$). Therefore, transcription from the p3 and p4 promoters, which contain a consensus -10 region but no -35 for ${\sigma}^{HrdB}$ recognition, are likely to be regulated by transcription factor(s) that modulate RNA polymerase holoenzyme activity in S. coelicolor.

• 한국작물학회지
• /
• 제43권2호
• /
• pp.89-94
• /
• 1998

Granule bound starch synthase (GBSS), also known as the '"waxy protein'", is responsible for the synthesis of amylose in the amyloplasts of cereal crops. In hexaploid wheat (Triticum aestivum L.), GBSS is involved in amylose synthesis and rolls as an important factor to determine flour quality and end-use quality in food products. Genes on three Wx loci have been found to encode GBSS in common wheats. We developed techniques for the purification and separation of GBSS in wheat. Three major GBSS isoforms, which were encoded by the genes on three loci, Wx-A1, Wx-B1, and Wx-D1 migrating differently by one dimensional SDS-po-lyacrylamide gel electrophoresis (1D SDS-PAGE), were identified. GBSS from 66 Korean hard and soft winter wheats were purified and determined for their Wx loci and four of them were identified possessing a null allele either at the Wx-A1 and Wx-B1 loci. With help of identification of three GBSS isoforms using 1D SDS-PAGE system, we are able to identify and monitor Wx gene expressions in breeding materials for developing waxy or partial waxy wheats without experiencing consecutive selecting generations.cting generations.

• 한국식품영양학회지
• /
• 제10권4호
• /
• pp.503-508
• /
• 1997

L. edodes의 배양액 및 균사체로부터 항암작용이 있는 단백 다당류의 추출 및 정제방법에 관한 실험을 실시하였다. 단백다당류 추출에서 비이온성 계명 활성제인 2% Triton X-100 용액으로 추출할 경우 상온에서 추출하여도 통상의 10$0^{\circ}C$ 열수 추출을 통해 얻을 수 있는 것보다 수율이 높았다. 그러나 계명활성제 용액에 4N NaCl을 첨가하여 추출하면 ethanol 침전과정에서 단백다당류의 침전물을 얻을 수 없었다. 열수 추출에 있어서 추출 온도는 10$0^{\circ}C$가 효과적이고 추출 시간은 4시간 정도면 충분하였다. 열수 추출 결과 ethanol 침전 및 동결건조를 통하여 얻어진 조단백 다당류의 정제 실험에서는 alumina를 충전제로 하는 gel filtration보다 sephadex에 의한 gel filtration 또는 DEAE-cellulose, DEAE-sephadex를 이용한 ion exchange chromatography가 보다 효과적이다.

• Journal of Microbiology and Biotechnology
• /
• 제16권7호
• /
• pp.1017-1025
• /
• 2006

Hantaviruses possess three RNA segments of negative sense. Co-infection of closely related hantaviruses may result in generation of a progeny virus with genomic polyploidy, containing a partial or complete set of genome originated from more than one parental virus. To characterize the formation of viral genomic polyploidy, cultured Vero-E6 cells were co-infected with two closely related hantaviruses, Hantaan and Maaji, and the progeny viruses examined. The genotype of plaque-purified viruses was analyzed by a virus-specific RT-PCR. Seventy percent (67/96) of the progeny virus was categorized as Hantaan and 3.3% (2/96) was classified as Maaji, whereas 20% (21/96) was considered polyploidy as they contained both types of the S RNA segment. Most of the polyploidy progeny viruses were unstable and gave rise to either one of the parental viruses or a reassortant after several rounds of plaque purification. No recombination between the heterologous pair of S RNA was observed for those polyploid viruses during three consecutive plaque-to-plaque passages. These data suggest that the viral polyploidy formation constitutes a primary mechanism underlying the generation of a newly emerged hantavirus.

• 한국미생물·생명공학회지
• /
• 제8권2호
• /
• pp.125-133
• /
• 1980

토양으로부터 분리한 포도당 이성화효소를 강하게 생산하는 방사균을 Bergey's manual 8판에 따라 동정한 결과 Streptomyces antibioticus 근록의 균주이었다. 본 균의 배양액으로부터 균체를 모아서 해사를 넣고 파쇄 하여 증류수로 추출하고 Mn-처리를 하여 핵단백질을 제거한 후 황산 ammonia 분획침전(0.5∼0.8포화), 수석, DEAE-cellulose column chromatography, DEAE-sephadex (A-50) column chromatography 및 sephadex G-200에 의한 gel filtration을 거쳐 비활성도로 약 380배, 회수율 25％ 정도로 분리 정제하였다.

• Journal of Microbiology and Biotechnology
• /
• 제21권5호
• /
• pp.470-476
• /
• 2011

A potent fungus for amylase production, Chrysosporium asperatum, was isolated from among 30 different cultures obtained from wood samples collected in the Junagadh forest, India. All of the isolated cultures were screened for their ability to produce amylase by submerged fermentation. Among the selected cultures, C. asperatum (Class Euascomycetes; Onygenales; Onygenaceae) gave maximum amylase production. In all of the different media tested, potato starch was found to be a good substrate for production of amylase enzyme at $30^{\circ}C$ and pH 5.0. Production of enzyme reached the maximum when a combination of starch and 2% xylose, and organic nitrogen (1% yeast extract) and ammonium sulfate were used as carbon and nitrogen sources, respectively. There was no significant effect of metal ions on enzyme activity. The enzyme was relatively stable at $30^{\circ}C$ for 20 min, and no inhibitory effect of $Ca^{+2}$ ions on amylase production was observed.

• 한국식품영양과학회지
• /
• 제20권3호
• /
• pp.241-245
• /
• 1991

참취로부터 추출한 poluphenol oxidase의 부분정제를 $(NH_4)_2SO_4$ 처리 및 Sephadex G-150 column chromatogaphy에 의해 분리하였다. Polypenol oxidase의 최적pH와 최적온도는 각각 7.0과 $30^{\circ}C$였으며, 효소활성은 $60^{\circ}C$에서 30분간 처리시와 $70^{\circ}C$에서 5분간 처리시 완전실활하였다. 기질특이성에서는 chlorogenic acid의 기질이 높은 특이성을 나타난 반면 DL-dopa는 활성을 억제하였다. Polyphenol oxidase의 Km값은 17.6mM이었다.

• 한국식품영양과학회지
• /
• 제16권2호
• /
• pp.128-135
• /
• 1987

고온성 cellulose 분해이용세균인 Herpetosiphon geysericola CUM 317 균주가 생성하는 ${\alpha}-amylase$, ${\beta}-amylase$ 및 glucoamylase를 황산암모늄 염석, DEAE-cellulose chromatography, CM-cellulose chromatography 방법으로 각각 부분정제하였다. 이들 ${\alpha}-amylase$, ${\beta}-amylase$ 및 glucoamylase의 감자 전분에 대한 Km치는 $2.31mg/m{\ell}$, $7.69mg/m{\ell}$ 및 $8.33mg/m{\ell}$였으며, 각 분자량은 84,000 dalton, 76,000 dalton 및 80,000 dalton의 크기로 나타났다.

• BMB Reports
• /
• 제39권5호
• /
• pp.546-555
• /
• 2006

An acidic polysaccharide fraction that had high anti-complementary activity was isolated from the stems of Grey Mangrove in 0.15% yield. The final fractions was designated HAM-3-IIb-II. The polysaccharide fraction appeared to be homogenous by high performance size exclusion chromatography with an estimated molecular weight of 105 kDa. The isolated polysaccharide is more effective than polysaccharide K (PSK) in its anti-complementary activity at 58 ${\mu}g/ml$ of PSK and 23 ${\mu}g/ml$ of HAM-3-IIb-II that inhibit 50% of complement activity in the complement fixation assay. Structural studies indicated that HAM-3-IIb-II was rich in galacturonic acid along with arabinose, galactose and rhamnose, characterizing a pectin-type polysaccharide, which was also confirmed by FT-IR spectrum. The presence of rich neutral sugar side chains of arabinogalactans may have contributed to the expression of high activity. Traditionally, this mangrove plant is used for medicinal purposes and it appears to have some scientific applications.

• Toxicological Research
• /
• 제24권3호
• /
• pp.169-174
• /
• 2008

This study examined the mechanisms underlying the effects of the vasorelaxation active substance(VAS), dimethyladenosine-5'-L-arabinose, and its partial purification fraction on nitric oxide synthase in improving erectile dysfunction with particular focus on the nitric oxide (NO)-cGMP pathways. Two rat models, 9-month-old SD rats and 11-month-old SD rats, were given VAS(40 mg/kg per day) for 4 days, The aqueous fraction of silworm male pupae extract; semi-purified VAS(100 mg/kg per day) for 10 days, respectively. The NOS activities of the following three enzymes were examined: neuronal NO synthase(nNOS), inducible NOS(iNOS), endothelial NOS(eNOS), vascular endothelial growth factor on endothelial cells(VEGF) and anti-inflammation effect of Tumor necrosis factor-$\alpha$. The results showed increases in the nitric oxide synthase activities. Western blotting of the tissue homogenate showed an increase in the nNOS level in the brain and tongue, and an increase in the endothelial NO synthase(eNOS) level in penis. However, there was little association with VEGF production in HUVEC endothelial cells and no relationship with TNF-$\alpha$ which showed low levels.