排序方式: 共有3条查询结果,搜索用时 4 毫秒
1
1.
目的观察血红素氧合酶-1(HO-1)与雷帕霉素对血小板源性生长因子-BB(PDGF-BB)诱导的大鼠血管平滑肌细胞(VSMCs)表型转化的作用。方法原代大鼠VSMCs给予PDGF-BB诱导表型转化。同时给予不同剂量的血红素氧合酶诱导剂氯血红素诱导HO-1的表达,和雷帕霉素共培养24h。结果PDGF-BB20nmol/ml作用原代VSMCs24h后,SM-α-actin与PCNA表达减弱,PCNA表达增强。氯血红素诱导HO-1后可以抑制PDGF-BB诱导的VSMCs表型改变,并且随剂量的增加,抑制强度增加。较低剂量的雷帕霉素可以抑制PDGF诱导的VSMCs表型转化。结论PDGF-BB亚型可以促进原代培养的大鼠VSMCs由收缩表型向合成表型转化,给予氯血红素诱导HO-1表达可以对抗PDGF-BB诱导的大鼠VSMCs表型转化,并呈剂量相关。 相似文献
2.
Peter A. Jenkins Susan Boland Paul Kavanagh Dnal Leech 《Bioelectrochemistry (Amsterdam, Netherlands)》2009,76(1-2):162
We are interested in investigating the applications of biocatalytic mediated reduction of oxygen by oxygenases in films on electrode surfaces, as such reactions can form the basis for biosensors or biocatalytic fuel cell development. Here we present approaches aimed at improving the stability and signal output of such films. These include selection of oxygen reducing biocatalysts which are active under physiological conditions and development of redox mediators which offer the opportunity to tailor the mediator to each enzyme. It was found that for each enzyme Melanocarpus albomyces laccase (MaL), Trametes hirsutus laccase (ThL) or bilirubin oxidase (MvBOD) it was the biocatalytic films mediated by Os(2,2′-bipyridine)2Cl·PVI that not only generated the highest current densities compared to Os(4,4′-dimethyl-2,2′-bipyridine)2Cl·PVI and Os(4,4′-dichloro-2,2′-bipyridine)2Cl·PVI, but also proved to be the most stable over 48 h. Under physiological conditions electrodes constructed from MvBOD generated the highest initial current densities for each of the osmium redox polymers, however these films proved to be the least stable over 48 h. Stability could be improved using surface pre-treatment. 相似文献
3.
Roberto Zazueta-Sandoval Vanesa Zazueta Novoa Hortencia Silva Jiménez Roberto Cabrera Ortiz 《Applied biochemistry and biotechnology》2003,108(1-3):725-736
A spectrophotometric method of measuring oxygenase activity in cell extracts or in zymograms was developed. It is an easy
and cheap method that allows spectrophotometric measurement of activity by a colored reaction and reveals activity bands in
a polyacrylamide gel electrophoresis (PAGE) gel as brown bands. To prove its usefulness, we report on a study with the oxygenase
present in strain YR-1, isolated from petroleum-contaminated soils, that uses hydrocarbons as its sole carbon source. Soluble
oxygenase activity was detected (under our conditions of cellular homogenization) in the mycelium of a filamentous fungus
strain named YR-1. Oxygenase activity from aerobically grown mycelium was detected in growth medium containing the hydrocarbons
decane or hexadecane; the enzyme activity exhibited similar optimum pH for the hydroxylation of different aliphatic or aromatic
substrates (decane, hexadecane, benzene, and naphthalene) to the corresponding alcohols. Zymogram analysis conducted with
partially purified fractions from cell extracts from the aerobic mycelium of the YR-1 strain indicated the existence of only
one oxygenase enzyme. Partially purified samples of enzyme, analyzed by sodium dodecyl sulfate PAGE, indicated the presence
of one major protein band with a mol wt of 56 kDa that can be a constituent of the native enzyme. In samples of the enzyme,
the 56-kDa protein gave a positive reaction in immuno-detection experiments with antibodies directed against oxygenase from
soybean. The partially purified enzyme oxidized different substrates, although higher activity was displayed with benzene.
K
m
values obtained for benzene and decane indicated a higher affinity for the latter 相似文献
1