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931.
Bo-Hwa Lee Bo-Kyung Kim You-Jung Lee Chung-Han Chung Jin-Woo Lee 《Enzyme and microbial technology》2010,46(1):127
Rice bran and yeast extract were found to be the best combination of carbon and nitrogen sources for the production of carboxymethycellulase (CMCase) by Bacillus subtilis subsp. subtlis A-53. Optimal concentrations of rice bran and yeast extract for the production of CMCase were 5.0% (w/v) and 0.10% (w/v), respectively. Optimal temperature and initial pH of medium for cell growth of B. subtilus subsp. subtilis A-53 were 35 °C and 7.3, whereas those for the production of CMCase by B. subtilus subsp. subtilis A-53 were 30 °C and 6.8. Optimal agitation speed and aeration rate in a 7 L bioreactor were 300 rpm and 1.0 vvm, respectively. The optimal agitation speed and aeration rate for the production of CMCase by B. subtilus subsp. subtilis A-53 were lower than those for cell growth. The highest productions of CMCase by B. subtilus subsp. subtilis A-53 in 7 and 100 L bioreactors were 150.3 and 196.8 U mL−1, respectively. 相似文献
932.
Ming Kei Chung He Li Evan R. Williams Stephen M. Rappaport 《Analytical biochemistry》2010,400(1):123-129
Adducts of benzo[a]pyrene-diolepoxide (BPDE) with blood nucleophiles have been used as biomarkers of exposure to polycyclic aromatic hydrocarbons (PAHs). The most popular such assay is a competitive enzyme-linked immunosorbent assay (ELISA) that employs monoclonal antibody 8E11 to detect benzo[a]pyrene tetrols following hydrolysis of BPDE adducts from lymphocyte DNA or human serum albumin (HSA). Here we used 8E11 as the capture antibody in a sandwich ELISA to detect BPDE-HSA adducts directly in 1-mg samples of HSA or 20 μl of serum/plasma. The assay employs an anti-HSA antibody for detection, and this is amplified by an avidin/biotinylated horseradish peroxidase complex. The sandwich ELISA has advantages of specificity and simplicity and is approximately 10 times more sensitive than the competitive ELISA. To validate the assay, HSA samples were assayed from three populations with known high PAH exposures (coke oven workers), medium PAH exposures (steel factory control workers), and low PAH exposures (volunteer subjects) (n = 30). The respective geometric mean levels of BPDE-HSA adducts—67.8, 14.7, and 1.93 ng/mg HSA (1010, 220, and 28.9 fmol BPDE equiv/mg HSA)—were significantly different (P < 0.05). The sandwich ELISA will be useful for screening PAH exposures in large epidemiologic studies and can be extended to other adducts for which capture antibodies are available. 相似文献
933.
Mi Heon Ryu Hyung Mok Park Jin Chung Hae Ryoun Park 《Biochemical and biophysical research communications》2010,393(1):11-8
With progressive and rapid growth of malignant tumors, cancer cells in an ischemic condition are expected to develop an increased potential for local invasive growth. To address this hypothesis, we first examined the effect of hypoxia on the invasiveness of oral squamous cell carcinoma (OSCC) cells using the Matrigel invasion assay. We then investigated the effect of hypoxia on the protein and mRNA expression of α5 integrin and fibronectin, which are major factors involved in tumor cell invasion. We showed that (i) hypoxia increased the invasiveness of OSCC cells, (ii) α5 integrin and fibronectin protein and mRNA expression levels were increased in OSCC cells under hypoxic conditions, (iii) hypoxia stimulated autocrine secretion of fibronectin in OSCC cells, (iv) administration of siRNAHIF-1α caused a significant decrease in α5 integrin and fibronectin protein, confirming that HIF-1α plays a role in their induction, and (v) siRNAHIF-1α abrogated hypoxia-induced cell invasion. Collectively, these data suggest that hypoxia promotes OSCC cell invasion that is elicited by HIF-1α-dependent α5 integrin and fibronectin induction. 相似文献
934.
Tauroursodeoxycholate (TUDCA), chemical chaperone, enhances function of islets by reducing ER stress
Yeon Yi Lee Shin Hee Hong Ye Jin Lee Sung Soo Chung Hye Seung Jung Sang Gyu Park Kyong Soo Park 《Biochemical and biophysical research communications》2010,397(4):735-739
The exposure to acute or chronic endoplasmic reticulum (ER) stress has been known to induce dysfunction of islets, leading to apoptosis. The reduction of ER stress in islet isolation for transplantation is critical for islet protection. In this study, we investigated whether tauroursodeoxycholate (TUDCA) could inhibit ER stress induced by thapsigargin, and restore the decreased glucose stimulation index of islets. In pig islets, thapsigargin decreased the insulin secretion by high glucose stimulation in a time-dependent manner (1 h, 1.35 ± 0.16; 2 h, 1.21 ± 0.13; 4 h, 1.17 ± 0.16 vs. 0 h, 1.81 ± 0.15, n = 4, p < 0.05, respectively). However, the treatment of TUDCA restored the decreased insulin secretion index induced by thapsigargin (thapsigargin, 1.25 ± 0.12 vs. thapsigargin + TUDCA, 2.13 ± 0.19, n = 5, p < 0.05). Furthermore, the culture of isolated islets for 24 h with TUDCA significantly reduced the rate of islet regression (37.4 ± 5.8% vs. 14.5 ± 6.4%, n = 12, p < 0.05). The treatment of TUDCA enhanced ATP contents in islets (27.2 ± 3.2 pmol/20IEQs vs. 21.7 ± 2.8 pmol/20IEQs, n = 9, p < 0.05). The insulin secretion index by high glucose stimulation is also increased by treatment of TUDCA (2.42 ± 0.15 vs. 1.92 ± 0.12, n = 12, p < 0.05). Taken together, we suggest that TUDCA could be a useful agent for islet protection in islet isolation for transplantation. 相似文献
935.
936.
S. -Y. Kang K. J. Lee G. -J. Lee J. -B. Kim S. -J. Chung J. Y. Song B. -M. Lee D. S. Kim 《Biologia Plantarum》2010,54(1):61-68
Among the 400 soybean (Glycine max) landraces, we selected 3 tolerant (KAS150-9, KAS160-15, and KAS170-9) and 3 susceptible lines (KAS160-14, KAS160-20, and
KAS201-6-1) by the survival percentage and injury scores. Susceptible lines showed decrease in chlorophyll content and increase
in glucose and malondialdehyde (MDA) contents under waterlogging stress, while tolerant lines did not change significantly.
For AFLP analysis, 8 EcoRI (+3) and 8 MseI (+3) primers used in 32 primer combinations generated a total of 2 566 bands with a mean of 80 bands per primer combination,
of which 1 117 (43.5 %) were clearly polymorphic between the tolerant and susceptible lines. A genetic similarity coefficient,
based on cluster analysis using an unweighted pair grouping method of average (UPGMA), was 0.79 for the tolerant group, while
the susceptible landraces were genetically less related, with a genetic similarity coefficient of 0.17. The 10 reproducible
polymorphic PCR products present in the 3 tolerant or susceptible lines were sequenced and converted into sequence tagged
site (STS) markers. These STS primer sets were designated GmWT01-GmWT06 and GmWS01-GmWS04. Two STS primer sets, GmWT06 and
GmWS02, generated a single monomorphic PCR product identical in size to the original AFLP fragments. For the broad application
of these STS markers in marker-assisted selection (MAS) for soybean genotypes tolerant to waterlogging stress, two developed
STS markers are being evaluated with putative waterlogging tolerant mutant lines induced by γ-radiation in soybean mutation
breeding programs. 相似文献
937.
938.
Gaoneng Shao Shaoqing Tang Ju Luo Guiai Jiao Xiangjin Wei Ao Tang Jianli Wu Jieyun Zhuang Peisong Hu 《遗传学报》2010,37(8):523-531
A residual heterozygous line(RHL)carrying a heterozygous segment between two SSR loci RM11 and RM134 on the rice chromosome 7 was selected from a set of recombinant inbred lines from the cross D50(javanica)/HB277(indica).The former parent produces much longer grains than the latter.Selfed progenies of this selection were analyzed genotypically(SSRs)and phenotypically(grain length).Grain length was discontinuously variable in the mapping populations,allowing for the placement of this QTL qGL7-2 within a~4.8 cM interval defined by RM351 and RM234.A set of new markers within this region were developed,which narrowed the QTL to a 278 kb region defined by the markers Indel1 and RM21945.This region contains 49 predicted genes.The results also suggest that the novel allele for grain length will be used for the application of marker assisted selection for the improvement of grain length. 相似文献
939.
Jong‐Rok Jeon Eun‐Ju Kim Kumarasamy Murugesan Hyo‐Keun Park Young‐Mo Kim Jung‐Hee Kwon Wang‐Gi Kim Ji‐Yeon Lee Yoon‐Seok Chang 《Microbial biotechnology》2010,3(3):324-335
Laccase efficiently catalyses polymerization of phenolic compounds. However, knowledge on applications of polymers synthesized in this manner remains scarce. Here, the potential of laccase-catalysed polymerization of natural phenols to form products useful in hair dyeing was investigated. All 15 tested phenols yielded coloured products after laccase treatment and colour diversity was attained by using mixtures of two phenolic monomers. After exploring colour differentiation pattern of 120 different reactions with statistical regression analysis, three monomer combinations, namely gallic acid and syringic acid, catechin and catechol, and ferulic acid and syringic acid, giving rise to brown, black, and red materials, respectively, were further characterized because such colours are commercially important for grey hair dyeing. Selected polymers could strongly absorb visible light and their hydrodynamic sizes ranged from 100 to 400 nm. Analyses of enzyme kinetic constants, liquid chromatography and electrospray ionization-mass spectrometry (ESI-MS) coupled with collision-induced dissociation MS/MS indicate that both monomers in reactions involving catechin and catechol, and ferulic acid and syringic acid, are coloured by heteropolymer synthesis, but the gallic acid/syringic acid combination is based on homopolymer mixture formation. Comparison of colour parameters from these three reactions with those of corresponding artificial homopolymer mixtures also supported the idea that laccase may catalyse either hetero- or homo-polymer synthesis. We finally used selected materials to dye grey hair. Each material coloured hair appropriately and the dyeing showed excellent resistance to conventional shampooing. Our study indicates that laccase-catalysed polymerization of natural phenols is applicable to the development of new cosmetic pigments. 相似文献
940.
Nan Jiang Eun-Hee Jeon Jung-Hun Pak Tae-Joung Ha In-Youl Baek Woo-Suk Jung Jai-Heon Lee Doh-Hoon Kim Hong-Kyu Choi Zheng Cui Young-Soo Chung 《Plant biotechnology reports》2010,4(4):253-260
Plant secondary metabolites have always been a focus of study due to their important roles in human medicine and nutrition. We transferred the isoflavone synthase (IFS) gene into soybean [Glycine max (L.) Merr.] using the Agrobacterium-mediated transformation method in an attempt to produce transformed soybean plants which produced increased levels of the secondary metabolite, isoflavone. Although the trial to produce transgenic plant failed due to unestablished hygromycin selection, transformed callus cell lines were obtained. The induction rate and degree of callus were similar among the three cultivars tested, but light illumination positively influenced the frequency of callus formation, resulting in a callus induction rate of 74% for Kwangan, 67% for Sojin, and 73% for Duyou. Following seven to eight subcultures on selection media, the isoflavone content of the transformed callus lines were analyzed by high-performance liquid chromatography. The total amount of isoflavone in the transformed callus cell lines was three- to sixfold higher than that in control callus or seeds. Given the many positive effects of isoflavone on human health, it may be possible to adapt our transformed callus lines for industrialization through an alternative cell culture system to produce high concentrations of isoflavones. 相似文献