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1.
目的 研究茵陈中3个香豆素小分子与牛血清白蛋白(BSA)结合作用的机制.方法 荧光猝灭法和紫外吸收光谱法.结果 茵陈香豆素类小分子能够插入牛血清白蛋白内部与牛血清白蛋白形成复合物导致牛血清白蛋白内源性荧光猝灭,药物分子的极性对内源性荧光猝灭有一定的影响,猝灭机制主要为静态猝灭和非辐射能量转移.结合过程的热力学参数变化表明,上述相互作用过程是一个熵增的自发分子间作用过程.结论 牛血清白蛋白与茵陈香豆素类小分子间有较强的结合作用,且结合力以疏水作用为主,其中东莨菪内酯还存在偶极-偶极作用.  相似文献   

2.
目的研究咪唑斯汀与牛血清白蛋白(BSA)的相互作用机制和作用类型。方法用荧光光谱法检测Stern-Volmer猝灭常数,用紫外分光光度法(UV)和圆二色谱法(CD)检测咪唑斯汀对牛血清白蛋白构象的影响。结果用上述检测方法获得不同温度下咪唑斯汀与牛血清白蛋白的猝灭常数和热动力学参数。结论静态猝灭是咪唑斯汀导致BSA荧光猝灭的主要原因。不同温度下计算的热动力学参数表明,咪唑斯汀与牛血清白蛋白分子间的结合力以疏水作用力为主。上述二者的结合导致BSA的构象发生改变。  相似文献   

3.
目的:研究红花忍冬黄酮类成分与牛血清白蛋白(BSA)结合作用的机制。方法:采用荧光猝灭法和紫外吸收光谱法计算黄酮类分子与BSA的结合常数和结合距离,并根据热力学参数确定它们之间的主要作用力类型。结果:红花忍冬黄酮类小分子能够插入BSA内部与BSA形成复合物,导致BSA内源性荧光猝灭,黄酮分子中羟基对内源性荧光猝灭有一定的影响,猝灭机理主要为静态猝灭和非辐射能量转移。结合过程的热力学参数变化表明上述过程是一个熵增的自发分子间作用过程。结论:BSA与红花忍冬黄酮类小分子间有较强的结合作用,且结合以疏水作用为主,同时还存在偶极-偶极作用。  相似文献   

4.
黄芩苷与牛血清白蛋白的相互作用   总被引:4,自引:2,他引:4  
目的:研究生理pH值下黄芩苷与牛血清白蛋白(BSA)间的相互作用机制.方法:主要应用了荧光猝灭法及能量转移原理.结果:黄芩苷对BSA荧光猝灭方式是静态猝灭;结合距离小于7 nm.结论:黄芩苷与BSA间有较强的结合作用,可以被血清白蛋白储存和转运.  相似文献   

5.
目的:研究灯盏花素与牛血清白蛋白相互作用的荧光猝灭类型、结合位点、结合常数和作用力类型。方法:采用紫外-可见分光光度法和荧光光谱法研究两者的相互作用,并通过计算得到相关参数。结果:通过紫外-可见分光光度法发现,在灯盏花素的作用下,牛血清白蛋白的最大吸收峰发生了轻微蓝移,蛋白质疏水性增强;通过荧光光谱法发现,灯盏花素与牛血清白蛋白作用的猝灭类型为静态-动态联合猝灭,其中静态猝灭起主导作用。通过计算热力学参数,得到两者的相互作用力主要为静电引力。结论:阐明了灯盏花素和牛血清白蛋白相互作用的机制,建立了灯盏花素和牛血清白蛋白的结合模型。  相似文献   

6.
目的研究山萘酚(kaem pferol,KF)与牛血清白蛋白(bovine serumal bumin,BSA)相互作用的特征。方法应用荧光光谱法检测KF对BSA内源性荧光的猝灭作用,应用校正的Stern-Volmer方程计算动态荧光猝灭常数和静态猝灭常数,应用荧光猝灭双对数方程计算KF与BSA之间的结合位点数,并且根据热力学参数,推断结合反应的主要作用力类型,在此基础上根据Frster的偶极-偶极非辐射能量转移理论计算KF与BSA结合时供体-受体之间的结合距离和能量转移效率。结果 KF对BSA荧光猝灭机制为静态猝灭和动态猝灭的复合方式,结合常数KA在108数量级,结合位点数接近2,结合距离r=1.45nm,能量转移效率E=0.73,作用力类型为疏水作用。结论 KF可通过动态和静态猝灭结合的机制对BSA的内源性荧光产生明显的猝灭作用,两者之间的结合力为疏水作用。  相似文献   

7.
曲克芦丁与牛血清白蛋白相互作用的光谱研究   总被引:1,自引:0,他引:1  
目的: 应用光谱技术研究曲克芦丁(troxerutin, TRO)与牛血清白蛋白(bovine serum albumin,BSA) 间结合作用机制.方法:通过荧光光谱法确定曲克芦丁对BSA的荧光猝灭机制.依据热力学参数讨论两者之间的主要作用力类型.利用同步荧光光谱考察曲克芦丁对BSA构象的影响.结果: 曲克芦丁对BSA的荧光猝灭机制为静态猝灭;反应的热力学参数ΔH=-77.06 KJ/mol,ΔS=-152.20 J/(mol·K).结论: 曲克芦丁与BSA之间的主要作用力是范德华力;曲克芦丁的加入使BSA构象发生了变化.  相似文献   

8.
为了从分子水平上认识有机小分子与牛血清白蛋白(BSA)的作用机制,本研究运用荧光光谱法和紫外光谱法研究了人体生理pH值条件下6-氨基-4-(4-氯)苯基-5-氰基-3-甲基-1-苯基吡啶[2,3-c]并吡唑(Ⅰ)对BSA的荧光猝灭和两分子间的相互结合反应.获得了不同温度下Ⅰ与BSA作用的猝灭常数(KSV)、结合常数(K)和结合位点数(n),得出分子间的结合距离(r)和能量转移效率(E),证实Ⅰ与BSA的相互结合作用为单一的静态猝灭过程,彼此作用力强,大约以1∶ 1相结合,并且主要以疏水作用力为主.  相似文献   

9.
目的为新型噻吩并嘧啶的开发与应用提供重要信息。方法应用荧光光谱、紫外可见光谱方法研究了2-环己氨基噻吩并[2,3-d]嘧啶-4(3H)-酮(HJA)与牛血清白蛋白(BSA)的相互作用。结果HJA能强烈猝灭BSA的荧光强度,其荧光猝灭机理为动态猝灭。在此基础上计算了二者相互作用的结合常数、结合位点数及热力学参数等。结论HJA分子与BSA分子以摩尔比1∶1结合,其结合反应主要是熵驱动,主要作用力是疏水力。  相似文献   

10.
目的研究新型光敏剂五聚赖氨酸-2-羰基酞菁锌(ZnPc-(Lys)5)与牛血清白蛋白(BSA)之间的相互作用。方法从BSA角度采用荧光光谱法和紫外可见光谱法通过荧光猝灭实验探讨ZnPc-(Lys)5与BSA相互作用的猝灭机制、结合常数及结合位点;从ZnPc-(Lys)5角度采用胶束荧光增敏法测定ZnPc-(Lys)5浓度通过Scatchard方程计算ZnPc-(Lys)5与BSA相互作用的结合常数和结合位点数。结果荧光猝灭实验结果表明ZnPc-(Lys)5对BSA的荧光有强烈的猝灭作用,猝灭机制主要是静态猝灭形成基态配合物。不同温度(298,303,308,313,318 K)的结合常数K1分别为12.1×104L/mol,7.69×104L/mol,6.12×104L/mol,4.57×104L/mol,3.76×104L/mol,结合位点数分别为0.93,1.02,1.07,1.13,1.17。Scatchard方程计算出298 K结合常数K2为1.557×105L/mol,结合位点数位1.07。结论从两个方面计算的结合常数和结合位点数基本一致,ZnPc-(Lys)5与血清白蛋白之间主要通过形成基态配合物的方式相互作用,进入血清白蛋白中1个结合位点。  相似文献   

11.
Objective To observe blood pressure change with age in salt-sensitive teenagers whose salt sensitivity were determined by repeated testing.Methods Salt sensitivity was determined through intravenous infusion of normal saline combined with volume-depletion by oral diuretic furosemide in 55 teenagers. After five years, salt sensitivity was re-examined and subject blood pressure was followed up. Blood pressure changes in salt-sensitive teenagers were compared to that of non-salt sensitive teenagers over five years.Results After 5 years, the repetition rate of salt sensitivity determined by intravenous saline loading is 92.7%. In teenagers with salt sensitivity on the baseline, both the systolic blood pressure increments and increment rates were much higher than non-salt sensitive teenagers (12.7±12.1 mmHg vs. 2.8±5.2 mmHg, P< 0.01; 12.2%± 12.0% vs. 2.5% ±4.4%, P< 0.001,respectively). There was a similar trend for diastolic blood pressure (8.4 ± 6.4 mmHg vs. 3.7 ± 6.4 mmHg, P = 0.052; 13.2% ±10.6 % vs. 6.8%± 10.1%, P = 0.053, respectively).Conclusions Salt sensitivity determined by intravenous saline loading showed good reproducibility. Blood pressure increments with age were much higher in salt-sensitive teenagers than non-salt sensitive teenagers, especially in terms of systolic blood pressure.  相似文献   

12.
Objective: To evaluatel the value of D-dimers in patients with acute aortic dissection (AAD). Methods: This study consisted of 16 patients with AAD and 27 non-AAD patients. Serum D-dimets were measured by Sta-Liatest D-DI immunoturbidimetric assay. Results: D-dimer level was higher (P < 0.001) in patients with AAD(7.91 ± 5.52 μg/ml) than that in non- AAD group(1.57±1.24 μg/ml). D-dimer was positive (>0.4 μg/ml) in all patients with AAD and in 10 control group patients (37%). Among patients with acute AAD, D-dimers tended to be higher in Stanford A than in Stanford B (8.67 ± 4.31 μg/ml vs. 3.24±1.27 μg/ml, P <0.01). D-dimer values tended to be higher in more extended disease(3.84 ± 1.65 μg/ml, 8.57 ± 3.58 μg/ml and 11.87 ± 5.69 μg/ml in thoracic aorta, thoracic and abdominal aorta, thoracic and abdominal aorta and iliacal arteries, respectively, P < 0.05 for both 8.57 ± 3.58 and 11.87 ± 5.69 vs. 3.84 ± 1.65 ). Including the control group into the analysis, we found a sensitivity of 100%, a negative predictive value of 100%, and a specificity of 66% and a positive predictive value of 64% for D-dimer in diagnosis of AAD in our patients with suspected AAD. Conclusion: D-dimer was elevated in patients with AAD. A negative D-dimer test result could be useful in excluding AAD.  相似文献   

13.
Objective: To set up a simple and reliable rat model of combined liver-kidney transplantation. Methods: SD rats served as both donors and recipients. 4℃ sodium lactate Ringer's was infused from portal veins to donated livers,and from abdominal aorta to donated kidneys, respectively. Anastomosis of the portal vein and the inferior vena cava (IVC) inferior to the right kidney between the graft and the recipient was performed by a double cuff method, then the superior hepatic vena cava with suture. A patch of donated renal artery was anastomosed to the recipient abdominal aorta. The urethra and bile duct were reconstructed with a simple inside bracket. Results: Among 65 cases of combined liver-kidney transplantation, the success rate in the late 40 cases was 77.5%. The function of the grafted liver and kidney remained normal. Conclusion: This rat model of combined liver-kidney transplantation can be established in common laboratory conditions with high success rate and meet the needs of renal transplantation experiment.  相似文献   

14.
Increasing maternal age is the only etiological factor unequivocally linked to Down's syndrome in humans. The occurrence rate of newborns with Down's syndrome is about 1/220 in women over 35 years old. However, the occurrence rate in embryos fertilized in vitro, of the elder woman is unclear. Using FISH we screened the number of chromosome 21 in preimplanted embryos of 5 elderly women (average age, 38.4 years) to study the feasibility and necessity of screening trisomy 21 in embryos in patients over 35 years old at the in vitro fertilization (IVF) center.  相似文献   

15.
Real-time three-dimensional echocardiography (RT3DE)is a new ultrasound technique that enables dynamic threedimensional visualization and quantification of the heart in real time. Investigation of feasibility and methodology of RT3DE in determining left ventricular (LV) and right ventricular (RV) volumes, RT3DE was performed in 35 normal adults using Philips SONOS 7500 system with a 2-4 MHz matrix array transducer. The 60°×60° "pyramid" volume database was obtained and analyzed on a TomTec echo workstation. Both LV and RV volumes were calculated with four 3DE methods (i.e. apical 2, 4, 8, and 16-plane) through manually tracing ventricular endocardial borders in end diastole and end systole. Stroke volumes were then calculated. LV volume was also measured by 2DE Simpson's rule using GE VIVID 7 ultrasound machine.  相似文献   

16.
A clinical guideline for the therapeutic interventions of integrative medicine may be defined as a written document which states a series of recommendations on therapeutic interventions of integrative medicine for a special disease or condition. The guideline may provide assistance to medical professionals in making clinical decisions aimed at improving the clinical outcome of patients and reducing the costs of medical care(~'4~. Recommendations issued by a guideline should be based on the best available evidence in both Western and Chinese medicine. For fulfilling this purpose, the development of clinical guidelines for therapeutic interventions in the field of integrative medicine should follow scientific principles and undergo a rigorous processes.  相似文献   

17.
Objective:To probe into the influence of changes of ovarian hormones on the pathogenesis of the specific sub-type premenstrual syndrome(PMS)and reveal partial microcosmic mechanisms of adverse flow of liver-qi.Methods:Estradiol(E2)and progesterone(P)levels in serum were determined at different phases of menstrual cycle by radioimmunoassay.Results:In the group of PMS with adverse flow of liver-qi.the secretive peak value Of E2 and P at the follicular phase significantly decreased,and the secretive peak value at the luteal phase did not come into being.Conclusions:Low E2 and P secretive peak at the follicular phase and absence of secretive peak at the luteal phase is one of the microcosmic mechanisms of PMS with adverse flow of liver-qi.One of the pathophysiologic mechanisms of specific sub-type PMS is probably the continuous low level of E2and P.  相似文献   

18.
Journal of Nanjing Medical University (English Edition) JNMU, sponsored by Nanjing Medical University, was established in 1987. It is a bimonthly comprehensive English medical journal published locally and abroad.Since 2007, Journal of Nanjing Medical University (English Edition )was granted Elsevier the full publishing and distribution rights worldwide for the Electronic Edition, excluding the People's Republic of China.  相似文献   

19.
Objective To measure Derpl and Blot5 allergen levels in asthmatics' homes in Hongkong.Methods Seventy houses were enrolled for a mite indoor environment study. Dust samples were obtained from two sites of each patients' house: bed and floor. Derpl and Blot5 levels were quantified by a two-site monoclonal antibody-based ELISA technique.Results The levels of Derpl allergens found in bed (geometric mean (GM) 3.43 μg/g of dust; 95%CI, 1.89-4.96 μg/g)and on the floor (GM 1.12 μg/g of dust; 95%CI, 0.71-1.53 μg/g) indicated significant differences (P=0.005). However, the levels of Blot5 allergens found in bed (GM 19.00 μg/g of dust; 95%CI, 0.89-38.90 μg/g) and on the floor (GM 6.14 μg/g of dust; 95%CI, 0.40-11.90 μg/g) showed no statistically significant difference. In addition, in regards to the exposure index for Derpl and Blot5 allergens found in bed and on the floor, 17.6% in bed and 8.6% on the floor had levels of Blot5 ≥ 10 μg/g of dust, higher than those obtained for Derp1 (7.2% and 0% in bed and on the floor respectively, P< 0.05); higher percentages in bed and on the floor (25.0% and 35.7%) were observed for levels of Blot5 =0 μg/g of dust as compared with Derpl in bed and on the floor (4.3% and 14.5% respectively, P< 0.05).Conclusions Derpl and Blot5 are the major allergens found in this regional study, Blot5 is a more potent allergen in Hongkong, probably reflecting the high level of exposure to Blomia tropicalis (Bt). Bt and Dermatophagoides pteronyssinus (Dp) allergens should be included for precise diagnosis and effective immuno-therapeutic treatment of mite allergy in Hongkong.  相似文献   

20.
ANTI-PROLIFERATION EFFECT OF ORIDONIN ON HL-60 CELLS AND ITS MECHANISM   总被引:4,自引:0,他引:4  
Objcetive To investigate the anti-proliferation effect of oridonin on leukemic HL-60 cells and its mechanism. Methods HL-60 cells in vitro in culture medium were given different concentrations of oridonin. The inhibitory rate of cells were measured by microculture tetrazolium (MTT) assay, cell apoptotic rate was detected by flow cytometry (FCM), morphology of cell apoptosis was observed by hoechst 33258 fluorescence staining, and the activity of telomerase was detected using telomere repeat amplification protocol (TRAP) PCR-ELISA before and after apoptosis occurred. Results Oridonin could decrease telomerase activity, inhibit growth of HL-60 cells, and cause apoptosis significantly. The suppression was both in time- and dose-dependent manner. Marked morphological changes of cell apoptosis including condensation of chromatin and nuclear fragmentation were observed clearly by hoechst 33258 fluorescence staining especially after cells were treated 48-60 hours by oridonin. Conclusions Oridonin has apparent anti-proliferation and apoptotic effects on HL-60 cells in vitro, decreasing telomerase activity of HL-60 cells may be one of its most important mechanisms. These results will provide strong laboratory evidence of oridonin for clinical treatment of acute leukemia.  相似文献   

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