Tb3+离子发光探针研究Ca2+,La3+和Al3+与拟南芥钙调素的竞争结合

利用Tb3 离子的发光, 研究了Tb3 与拟南芥钙调素 (CaM)结合的荧光光谱及荧光滴定曲线特点, 然后利用Tb3 4*CaM系统在221 nm直接激发和280 nm敏化激发的光谱变化研究了Ca2 , La3 和Al3 与拟南芥钙调素 (CaM) 的竞争结合作用. 结果表明: Tb3 , La3 与钙调素的竞争结合能力强于Ca2 , 而Tb3 的竞争结合力又大于La3 , Ca2 与钙调素的结合力远大于Al3 . 竞争实验的结果从分子水平上揭示了Tb3 , La3 和Al3 等金属离子生物效应可能的分子机制.     

Raman spectroscopy of CaM2+Ge2O6 (M2+ = Mg,Mn, Fe,Co, Ni,Zn) clinopyroxenes

The Raman spectra of Ge‐clinopyroxenes CaM²⁺Ge₂O₆ (M²⁺ = Mg, Mn, Fe, Co, Ni, Zn), general formula M2M1T₂O₆, are reported for the first time. Their spectral features are discussed in comparison with corresponding Si‐pyroxenes. The vibrational wavenumbers of germanates may be roughly obtained by a scale factor of about ~0.8 by those of the corresponding silicates, due to the Ge‐Si mass difference. The main peaks in the germanate Raman spectra at ~850 and ~540 cm⁻¹ may be related to Ge‐O tetrahedral stretching and chain bending, respectively; minor peaks between 200 and 400 cm⁻¹ are ascribed to bending and stretching of the non‐tetrahedral cations. Within Ge‐pyroxenes, possible correlations between crystallographic parameters and the vibrational wavenumbers are investigated. The main stretching mode at ~850 cm⁻¹ shows wavenumber changes with M²⁺ substitutions, but no simple correlation can be found with M²⁺ cation mass or size. On the other hand, the chain bending wavenumber linearly decreases with increasing ionic radius of the M²⁺ cation: the expansion of the M1 polyhedron reduces the chain kinking angle and the Ge‐Ge distances correspondingly increase. Copyright © 2015 John Wiley & Sons, Ltd.     

ＣaＭ激酶及其在植物体内的功能

介绍了CaM激酶的结构和生化特点，以及植物体内CaM激酶的研究进展。从植物细胞信号转导、发育和基因表达等３个方面讨论了CaM激酶激酶在植物体内的生理功能。     

ABA与Ca~(2+)-CaM对草莓叶片抗氧化防护酶系统影响

用外源植物激素脱落酸ABA(abscisic acid,ABA)处理草莓叶片,草莓体细胞的抗氧化防护酶活性升高,表明ABA作为植物信号分子可以诱导草莓这一对干旱较为敏感的植物的逆境响应.Fluridone处理未能抑制草莓细胞对外源ABA的响应.进一步研究表明,钙调素(Calmodulin,CaM)作为Ca2+传感蛋白,介导了草莓叶片细胞ABA的下游信号事件.     

蚯蚓钙调素结合蛋白的研究

以赤子爱胜蚓(Eisenia Foetida)为材料,通过DEAE-Fast Flow离子交换层析、CaM-Sepharose亲和层析,分离纯化得到蚯蚓钙调素结合蛋白(CaMBPs)。纯化的CaMBPs对CaM激活的环核苷酸磷酸二酯酶活性有抑制作用,而且这种抑制作用可通过加入过量的CaM达到完全恢复。SDS-PAGE显示CaMBPs有3条明显主带,在EGTA存在时表现分子量分别为62, 49和30kD。紫外扫描测定含量分别为7.17%,7.31%和51.8%。用生物素-CaM覆盖法检测到3种CaM结合蛋白,与SDS-PAGE结果一致。酶活性测定实验表明在蚯蚓CaMBPs中有Ca²⁺-ATPase活性,但无NAD激酶活性。     

钙调素特异性拮抗剂(TFP)对大鼠着床的影响

在大鼠孕４ｄ宫腔内一次性注入钙调素特异性拮抗剂－三氟拉嗪,每侧子宫角０．０５ｍＬ,具有显著的抗着床作用,抗着床率高达１００％,而注入等容量生理盐水的对照组为０％。     

硝酸铈对钙调素及调节蛋白Ca~(2 )-ATP酶基因表达的影响

运用逆转录聚合酶链式反应研究了硝酸铈对大白鼠肝脏CaMⅠ ,PMCA1b基因表达的影响。腹腔注射高、低浓度硝酸铈均不会引起CaMⅠ ,PMCA1b基因表达的变化 ,提示硝酸铈对钙调素、Ca2 ATP酶的影响可能仅处于转录后水平。     

番茄碱对棉铃虫毒性分析

本文主要研究了番茄碱对棉铃虫的毒性作用．实验结果表明：（1）用不同浓度的番茄碱（tomatine）浸泡的棉花叶饲喂棉铃虫时，随浓度的增加及时间的延长，对棉铃虫的杀伤力增强．结果显示：饲喂第三天时，1mmol／L的浓度引起48％死亡，2mmol／L时60％死亡，4mmol／L时76％死亡，其IC50为1．78mmol／L．（2）用紫外光谱分析测得虫体内钙调蛋白的含量，结果显示：tomatine对其体内钙调蛋白的影响较大，随tomatine浓度的增加，钙调蛋白的含量逐渐降低．（3）紫外光谱图谱显示：番茄碱与钙调蛋白形成了一种新的物质（其特征吸收峰在190nm-220nm）．说明tomatine对棉铃虫的杀伤作用与钙调蛋白有关，此项研究为进一步探讨tomatine的作用分子机制提供了科学参数．     

Involvement of Ca<Superscript>2+</Superscript>/CaM in the signal transduction of acetylcholine regulating stomatal movement

It has been known that the neurotransmitter acetylcholine (ACh) also exists in plants and is able to regulate the movement of stomata.In another aspect,Ca^2 /CaM as the second messengers have a critical role of signal transduction in stomatal guard-cell,Here we showed that Ca^2 /CaM were also involved in the ACh regulated stomatal movement,In the medium containing Ca^2 ,the Ca^2 channel blockers (NIF and Ver)and CaM inhibitors (TFP and W7 ) could neutralize the ACh induced stomatal opening,however,they are ineffective in the medium containing K^ ,Those results indicated that Ca^2 /CaM were involved in the signal transduction pathway of ACh regulating stomatal movement.