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991.
Haidong Ding Aying Zhang Jinxiang Wang Rui Lu Hong Zhang Jianhua Zhang Mingyi Jiang 《Planta》2009,230(2):239-251
Mitogen-activated protein kinase (MAPK) cascades have been shown to be important components in abscisic acid (ABA) signal
transduction pathway. In this study, a 46 kDa MAPK (p46MAPK) induced by ABA was partially purified from maize (Zea mays) by Q-Sepharose FF, Phenyl-Sepharose FF, Resource Q, Mono QTM 5/50 GL, poly-l-lysine-agarose, and Superdex 75 prep-grade columns, and was identified as ZmMAPK5 (gi|4239889) by the matrix-assisted laser
desorption/ionization time-of-flight/time-of-flight (MALDI-TOF/TOF) mass spectrometry. Furthermore, the kinase showed optimal
activity at pH 8.0, 30°C, and 10 mM MgCl2; the K
m
for myelin basic protein (MBP) substrate and ATP were 0.13 μg μl−1 and 62 μM, respectively. MBP was the preferred substrate, of which the threonine residue was phosphorylated. Finally, the
kinase was found to respond to diverse extracelluar stimuli. These results enable us to further reveal the function of the
ZmMAPK5 in ABA signaling.
The authors Haidong Ding and Aying Zhang contributed equally to the work. 相似文献
992.
993.
994.
利对重组枯草芽孢杆菌(pBES-pss)表达的磷脂酰丝氨酸合成酶进行分离纯化及酶学性质研究.pBES-pss发酵后的粗酶液经硫酸铵盐析、中空纤维膜除盐浓缩、SP-Sepharose HP离子交换层析和Sephadex G-75凝胶层析,基本获得电泳纯的重组磷脂酰丝氨酸合成酶,比活力可达13.62 U/mg,分子量约为53 kD.酶学性质研究表明,该酶催化卵磷脂水解反应的最适pH8.0,最适温度为35℃.稳定性研究表明:该酶在pH 6.5~9.5 区间和低于45℃温度下稳定.表面活性剂及金属离子对该酶水解活性的影响结果表明,SDS、Tween20、Tween80对该酶有抑制作用,Triton X-100对该酶有增强作用;Mg2+、Zn2+、K+对该酶有抑制作用,Ca2+、Mn2+和EDTA对该酶有增强作用. 相似文献
995.
中国苜蓿植物资源概述 总被引:1,自引:0,他引:1
综述了中国苜蓿属植物资源、品种资源及利用概况,并对苜蓿植物资源的进一步利用前景进行了探讨。 相似文献
996.
噬菌体裂解酶的抗菌特性 总被引:3,自引:0,他引:3
摘要:噬菌体裂解酶是一类细胞壁水解酶,可水解肽聚糖,造成细菌的破裂。裂解酶一般具有两到三个结构域,参与对底物的催化和结合。作为一种新型的杀菌制剂,裂解酶已被越来越多地应用于化脓链球菌、肺炎链球菌、金黄色葡萄球菌等革兰氏阳性细菌病的治疗。与抗生素治疗相比,裂解酶不易使细菌产生抗性且作用相对专一,这可能是解决现在日趋严重的细菌耐药性的一种可行方法。另外,裂解酶还具有高效性,作用协同性,且自身抗体不削弱其作用等优势,使之成为未来预防、控制致病菌一种可能的新途径。 相似文献
997.
固定化脂肪酶催化毛油合成生物柴油 总被引:5,自引:0,他引:5
本研究开发了一种用石油醚提取毛油的工艺,研究了以提取的毛油和甲醇为原料,用固定化Candida sp.99-125脂肪酶催化合成脂肪酸甲酯(FAMEs)的可行性。同时考察了磷脂对固定化酶活性、反应起始速率、固定化酶使用批次的影响以及毛油和精炼油对固定化酶使用批次等的影响。研究结果表明,用磷脂质量分数为1%的石油醚悬液浸泡过的脂肪酶比仅用石油醚浸泡过的脂肪酶初始转酯化速率显著下降。当大豆油中无磷脂时,15min时FAMEs的产率为26.2%;磷脂质量分数为5%时,FAMEs降为12.4%。当大豆油中磷脂质量分数小于1%时,固定化酶使用10个批次,FAMEs产率无明显变化。固定化脂肪酶催化石油醚浸提得到的大豆和小桐子毛油,经过10个批次反应FAMEs产率都保持在70%以上,该固定化酶直接催化毛油生产生物柴油具有良好的工业化前景。 相似文献
998.
999.
Background
Large conductance calcium-activated potassium channel (BKCa) plays an important role in the control of uterine contractility during pregnancy. The change from uterine quiescence to enhanced contractile activity may be associated with the spatial and temporal expression of BKCa within myometrium. The objectives of this study were to examine the expression of BKCa alpha- and beta-subunit in upper segment (US) and lower segment (LS) regions of uterus, and to investigate for the possibly differential expression of these proteins in US and LS myometrium obtained from three functional states: (1) non-pregnant (NP); (2) term pregnant not in labour (TNL) and (3) term pregnant in labour (TL). 相似文献1000.
Isolation and Characterization of Taiwanese Heterotrophic Microalgae: Screening of Strains for Docosahexaenoic Acid (DHA) Production 总被引:1,自引:0,他引:1
Huey-Lang Yang Chung-Kuang Lu Shu-Fen Chen Young-Mao Chen Yi-Min Chen 《Marine biotechnology (New York, N.Y.)》2010,12(2):173-185
Marine heterotrophic microalgal species which are potentially rich in docosahexaenoic acid (DHA, C22:6n−3) have been found in Taiwan; however, there was a lack of detailed analysis and characterization of these indigenous algae
which is needed for the development of commercial applications. Hence, the objective of this study was to screen DHA-rich
heterotrophic microalgae species indigenous to Taiwan for commercial purposes. Heterotrophic microalgae from a variety of
marine habitats were isolated, cultivated, and then identified according to their 18S rRNA gene sequences and morphological
characteristics. A comparison was made of their fatty acid profiles, fatty acid content, and amount of biomass. For the strain
with highest DHA yield, the optimal growth conditions were determined in order to establish the best fermentation conditions
for scale-up. In this study, 25 heterotrophic microalgal strains were successfully isolated from marine habitats around Taiwan.
All of the isolated strains showed a close phylogenic relationship with the Thraustochytriaceae family according to their
18S rRNA gene sequences. GC/MS analysis discerned seven distinctive fatty acid profiles of these strains, with the production
of eicosapentaenoic acid (C20:5n−3) ranging from 0.02 to 2.61 mg L−1, and DHA ranging from 0.8 to 18.0 mg L−1. An Aurantiochytrium strain BL10 with high DHA production was subsequently chosen for further manipulation. Under optimal growth conditions it
could produce up to 59.0 g of dry biomass per liter of culture, with dry biomass containing 73% total fatty acid and 29% DHA,
revealing BL10 as an excellent source of microbial DHA. 相似文献