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991.
992.
Youshuang Zhu Haibo Zhang Mingle Cao Zhenzhen Wei Feng Huang Peiji Gao 《Biotechnology and Bioprocess Engineering》2011,16(5):1027-1035
Production of laccase using a submerged culture of Trametes versicolor sdu-4 was optimized using a central composite design of the Response Surface Methodology. Optimized conditions gave a laccase
yield of 4,213 U/L which was approximately three times of that in basal medium. The laccase was purified to homogeneity using
a three-step process. The overall yield of the purification was 58%, with a purification fold of 11.4 and a specific activity
of 1320.7 U/mg protein. The molecular mass of the laccase was 60 kDa. The optimum pH values of the enzyme were 2.2, 3.7, and
7 for the oxidations of ABTS, DMP, and syringaldazine, respectively. The enzyme had adaptability to a broad pH range and high
temperature and wsa stable at pH 3.0 ∼ 10.0. The half-life of this laccase at 70°C was 2.2 h. Methyl red, 2-bromophenol, and
4-bromophenol were oxidized by the purified laccase in the absence of mediators. Purified laccase was effective in the decolorization
of several dyes and was not inhibited by Cu2+, Mn2+, Zn2+, Na+, K+, Mg2+, Ba2+, and Ca2+ at 5 mM. These excellent characteristics made it a highly attractive candidate for industrial use. 相似文献
993.
Cao Y Evans SC Soans E Malki A Liu Y Liu Y Chen X 《Apoptosis : an international journal on programmed cell death》2011,16(9):902-913
p53 is essential for cell cycle arrest and apoptosis induction while insulin receptor (IR) signaling is important for cell
metabolism and proliferation and found upregulated in cancers. While IR has recently been found to be involved in apoptosis,
p53 induction or apoptosis mediated through IR signaling activation has never been documented. Here, we report that the IR
signaling pathway, particularly the IR-MEK pathway, mediates biological and biochemical changes in p53 and apoptosis in tumor
cells. Specifically, natural compound penta-O-galloyl-α-d-glucopyranose (α-PGG), a previously characterized IR signaling activator, induced apoptosis in RKO cells without significantly
affecting its normal counterpart FHC cells. α-PGG induced apoptosis in RKO cells through p53, Bax and caspase 3. Importantly,
α-PGG’s ability to elevate p53 was diminished by IR inhibitor and IR-siRNA, suggesting a non-conventional role of IR as being
involved in p53 induction. Further studies revealed that α-PGG activated MEK, a downstream signaling factor of IR. Blocking
MEK significantly suppressed α-PGG-induced p53 and Bax elevation. All these results suggested that α-PGG induced p53, Bax,
and apoptosis through the IR-MEK signaling pathway. The unique activity of α-PGG, a novel IR phosphorylation and apoptosis
inducer, may offer a new therapeutic strategy for eliciting apoptotic signal and inhibiting cancer growth. 相似文献
994.
Zhang Y Yang Y Zhang H Jiang X Xu B Xue Y Cao Y Zhai Q Zhai Y Xu M Cooke HJ Shi Q 《Bioinformatics (Oxford, England)》2011,27(10):1436-1437
High-throughput deep-sequencing technology has generated an unprecedented number of expressed short sequence reads, presenting not only an opportunity but also a challenge for prediction of novel microRNAs. To verify the existence of candidate microRNAs, we have to show that these short sequences can be processed from candidate pre-microRNAs. However, it is laborious and time consuming to verify these using existing experimental techniques. Therefore, here, we describe a new method, miRD, which is constructed using two feature selection strategies based on support vector machines (SVMs) and boosting method. It is a high-efficiency tool for novel pre-microRNA prediction with accuracy up to 94.0% among different species. AVAILABILITY: miRD is implemented in PHP/PERL+MySQL+R and can be freely accessed at http://mcg.ustc.edu.cn/rpg/mird/mird.php. 相似文献
995.
MOTIVATION: Modeling of side chain conformations constitutes an indispensable effort in protein structure modeling, protein-protein docking and protein design. Thanks to an intensive attention to this field, many of the existing programs can achieve reasonably good and comparable prediction accuracy. Moreover, in our previous work on CIS-RR, we argued that the prediction with few atomic clashes can complement the current existing methods for subsequent analysis and refinement of protein structures. However, these recent efforts to enhance the quality of predicted side chains have been accompanied by a significant increase of computational cost. RESULTS: In this study, by mainly focusing on improving the speed of side chain conformation prediction, we present a RApid Side-chain Predictor, called RASP. To achieve a much faster speed with a comparable accuracy to the best existing methods, we not only employ the clash elimination strategy of CIS-RR, but also carefully optimize energy terms and integrate different search algorithms. In comprehensive benchmark testings, RASP is over one order of magnitude faster (~ 40 times over CIS-RR) than the recently developed methods, while achieving comparable or even better accuracy. 相似文献
996.
997.
A putative Type II restriction–modification system of Thermotoga neapolitana, TneDI, was cloned into Escherichia coli XL1-Blue MRF′ and characterized. Gene CTN_0339 specifies the endonuclease R.TneDI, while CTN_0340 encodes the cognate DNA methyltransferase M.TneDI. Both enzymes were purified simply by heating the cell lysates of E. coli followed by centrifugation. The enzymes were active over a broad range of temperatures, from 42°C to at least 77°C, with
the highest activities observed at 77°C. R.TneDI cleaved at the center of the recognition sequence (CG↓CG) and generated blunt-end cuts. Overexpression of R.TneDI in BL21(DE3) was confirmed by both SDS-PAGE and Western blotting. 相似文献
998.
Severe acute pancreatitis (SAP) is a common disease with a poor prognosis. Heart failure is one cause of SAP patient death.
Intermedin (IMD) is a potent endogenous cardio-protective substance. Administration of exogenous IMD showed beneficial effects
in cardiovascular diseases. The aim of this study was to investigate the myocardial damage in SAP and to determine the therapeutic
potential of IMD for SAP. Using an SAP rat model, we examined endogenous IMD expression following SAP induction, and determined
the effect of IMD on myocardial function, histological morphology, apoptosis-related gene expression, and prognosis. Our results
indicated that the cardiac function and histological structure were significantly disrupted in SAP rats. Infusion of exogenous
IMD significantly preserved cardiac function and ameliorated myocardial damage. Terminal deoxynucleotidyl transferase-mediated
dUTP nick end labeling (TUNEL) revealed that myocardial apoptosis was extensively present in SAP rats, and IMD infusion led
to increased expression of the prosurvival factor Bcl-2, but decreased pro-apoptotic factors Bax and caspase-3. In addition,
IMD infusion also reversed the change of IMD receptor systems in SAP rat heart tissue. Furthermore, we found that IMD infusion
greatly decreased mortality of SAP rats. In conclusion, administration of SAP produced therapeutic effects in SAP through
modulating apoptotic and pro-survival gene expression, inhibiting myocardial apoptosis, preserving cardiac function, and a
useful therapeutic agent for SAP, and provides us an insight for a clinical trial of IMD for treating human severe acute pancreatitis. 相似文献
999.
Zhang Y Xu P Lu C Kuang Y Zhang X Cao D Li C Chang Y Hou N Li H Wang S Sun X 《Marine biotechnology (New York, N.Y.)》2011,13(3):376-392
A genetic linkage map of common carp (Cyprinus carpio L.) was constructed using Type I and Type II microsatellite markers and a pseudo-testcross mapping strategy. The microsatellite markers were isolated from microsatellite-enriched genomic libraries and tested for their segregation in a full-sib mapping panel containing 92 individuals. A total of 161 microsatellite loci were mapped into 54 linkage groups. The total lengths of the female, male and consensus maps were 2,000, 946, and 1,852?cM, with an average marker spacing of approximately 13, 7, and 11?cM, respectively. Muscle fiber-related traits, including muscle fiber cross-section area and muscle fiber density, were mapped to the genetic map. Three QTLs for muscle fiber cross-section area and two QTLs for muscle fiber density were identified when considering both significant and suggestive QTL effects. The QTLs with largest effects for muscle fiber cross-section area and muscle fiber density were 21.9% and 18.9%, and they were located in LG3, respectively. 相似文献
1000.
Tian L Cao C He L Li M Zhang L Zhang L Liu H Liu N 《International journal of biological sciences》2011,7(6):902-911
Five BC? lines and 16 house fly mass-cross homozygous lines were generated from crosses of the pyrethroid resistant ALHF (wild-type) and susceptible aabys (bearing recessive morphological markers on each of five autosomes) strains. Each of the resulting homozygous lines had different combinations of autosomes from the resistant ALHF strain. Levels of resistance to permethrin were measured for each line to determine the autosomal linkage, interaction and, possibly, regulation in pyrethroid resistance of house flies. Results indicated that factors on autosome 4 are not involved in the development of resistance in house flies, while factors on autosomes 1, 2, 3 and 5 play important roles in pyrethroid resistance. The sodium channel gene has been mapped on autosome 3 and multiple cytochrome P450 genes overexpressed in resistant ALHF house flies have been genetically mapped on autosome 5, suggesting that P450 mediated detoxification and sodium channel-mediated target site insensitivity located on autosomes 3 and 5, respectively, are major factors related to resistance development in house flies. However, neither the factors on autosome 3 or 5 alone, nor the factors from both autosomes 3 and 5 combined could confer high levels of resistance to pyrethroid. In addition, strong synergistic effects on resistance was obtained when autosomes 1 and 2 interact with autosome 3 and/or 5, suggesting that the trans factors on autosomes 1 and 2 may interact with factors on autosomes 3 and 5, therefore, playing regulatory roles in the development of sodium channel insensitivity- and P450 detoxification-mediated resistance. 相似文献