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1.
新型噬菌粒展示载体pCANTAB5L的构建   总被引:4,自引:2,他引:4  
目的:将柔性多肽接头和多克隆位点引入噬菌粒载体pCANTAB5X中,构建适用于展示各种随机肽库、功能靶蛋白、功能靶蛋白变异体库和大分子量(>300个氨基酸)功能蛋白的新型噬菌粒展示载体。方法:应用5′端含XbaⅠ、StuⅠ、SalⅠ、KpnⅠ识别序列的引物,PCR扩增获得XbaⅠ-StuⅠ-SalⅠ-KpnⅠ-[G4S]3-NotⅠ衔接片段,将该PCR产物克隆到pMD-18T中,再将该片段插入pCANTAB5X中构建成新型噬菌粒展示载体pCANTAB5L。结果:限制性内切酶酶谱及DNA序列分析证明[G4S]3多肽接头和限制性内酶切位点XbaⅠ、StuⅠ、SalⅠ、KpnⅠ序列被引入到新构建的噬菌粒载体pCANTAB5L中。结论:成功构建了新型噬菌粒展示载体pCANTAB5L,并能有效展示功能靶蛋白、功能靶蛋白变异体库和大分子量功能蛋白。  相似文献   

2.
目的 构建免疫球蛋白结合分子金黄色葡萄球菌蛋白A(SPA)和链球菌蛋白G(SPG)单结构域随机组合噬菌体展示文库,为研究其分子功能与结构的关系奠定基础.方法 PCR扩增制备SPA的A、B、C 、D、 E结构域和SPG的B2结构域核苷酸片段,在片段两端通过引物引入XbaⅠ酶切位点和保护碱基,3′端引入3个氨基酸大小的随机连接肽核苷酸序列,各结构域核苷酸片段经XbaⅠ酶消化,在T4连接酶作用下随机相互连接并克隆于噬菌体展示载体pCANTAB5S,克隆产物转化E.coli DH5α,提取原代库质粒转化E.coli TG1,经M13K07辅助噬菌体拯救,构建成SPA和SPG单结构域随机组合噬菌体展示文库.结果 该噬菌体展示文库库容量为1.87×107 cfu,滴度为1.3×1014 TU/ml,文库的片段插入率近100%,其中插入多个结构域的阳性克隆占21.7%,序列分析显示各结构域之间的连接和随机连接肽序列具有随机性.结论 成功地构建了SPA和SPG单结构域随机组合噬菌体展示文库,该文库在库容量、多样性和随机性方面满足体外分子进化研究的要求.  相似文献   

3.
目的:构建HIV-1 Gag PR蛋白P2/NC切割位点序列随机化的噬菌体展示文库,研究HIV-1蛋白酶(protease PR)耐药性突变对其敏感切割序列的影响.方法:PCR扩增制备重组HIV-1 gag基因上的CAP2和NC片段,在CAP2片段5′端引入StuⅠ酶切位点,3′端PR切割位点处的氨基酸序列进行随机化;在NC片段5′端设计重叠区域,3′端引入SalⅠ酶切位点.应用Overlapping PCR将CAP2和NC片段拼接并克隆于噬菌体展示载体LD3-pCANTAB5S上,建立HIV-1PR靶蛋白CAP2和NC之间切割位点随机化的噬菌体展示文库.结果:该噬菌体展示文库库容量为2.1×106,滴度为3.0×1012TU/ml,CAP2/NC片段插入率为52.1%;12个样品的序列分析显示切割位点中随机化的核苷酸与氨基酸均呈随机性分布; 10个阳性单克隆噬菌体CAP2/NC-LD3-pCANTAB5S样品中9个与IgG特异结合.结论:成功地对HIV-1PR靶蛋白CAP2和NC之间切割位点进行了随机化并展示于噬菌体表面,构建了其噬菌体展示文库,为筛选耐药性突变的PR敏感切割序列及构建蛋白酶抑制剂噬菌体筛选模型打下基础.  相似文献   

4.
人胸腺素原α的克隆、表达和活性初步研究   总被引:2,自引:0,他引:2  
目的:构建由免疫球蛋白结合分子单结构域随机组合的噬菌体展示文库,为应用各种类型免疫球蛋白对该文库进行体外分子进化筛选研究打下基础.方法:PCR扩增制备分别编码Protein A的A、D结构域、Protein G的B2结构域和Protein L的B3结构域的序列片段,片段两端引入Xba Ⅰ酶切位点,3′端引入分别编码0、1、2、3个氨基酸大小随机连接肽的序列,并克隆于pMD-18T载体构建重组质粒.以上述16种重组质粒为模板,PCR扩增分别制备各种单结构域片段及两端部分T载体序列,XbaⅠ酶切,各种酶切片段混合后连接,并克隆于噬菌体展示载体pCANTAB5S,构建噬菌体展示免疫球蛋白结合分子单结构域随机组合文库,挑取单克隆进行序列测定,评价文库的随机性.结果:噬菌体展示免疫球蛋白结合分子单结构域随机组合文库库容量为2×107,滴度为1.3×1011;文库中含77%以上的阳性克隆,其中由2个以上单结构域组成的阳性克隆占24%;序列分析显示组合文库包含上述4种单结构域序列,连接方式符合随机连接的特点,随机连接肽的编码核酸也呈随机分布.结论:成功构建了免疫球蛋白结合分子单结构域随机组合文库,该文库库容、多样性和随机性完全可满足进行体外分子进化研究的要求.  相似文献   

5.
目的构建噬菌体展示IgA亲和体随机组合文库,研究IgA结合分子结构与功能的关系。方法基因合成IgA亲和体ZA1、ZA2片段。片段两端引入Kpn I酶切位点,3′端引入随机连接肽序列,Kpn I酶切,随机连接,克隆于噬菌粒展示载体pCANTAB5S的Kpn I克隆位点上,转化大肠杆菌TGI,辅助噬菌体M13K07拯救,构建噬菌体展示随机组合文库。结果基因合成IgA亲和体;构建噬菌体展示IgA亲和体随机组合文库,容量为3·4×107,滴度为1·6×1012TU/L;文库中含79%以上的阳性克隆;序列分析显示组合文库由ZA1、ZA2随机组合而成,连接方式符合随机连接的特点,各亲和体之间连接肽序列也呈随机分布。结论合成IgA亲和体,构建噬菌体展示IgA亲和体随机组合文库,该文库库容量、多样性和随机性可满足体外分子进化研究的要求。  相似文献   

6.
目的构建噬菌体展示免疫球蛋白结合分子定点随机突变组合文库,为应用各种类型免疫球蛋白对该文库进行体外分子进化筛选及结构和功能的研究打下基础。方法应用overlapping PCR制备Protein A的Z结构域。用含随机核苷酸序列的引物,制备对Z结构域的第10、13、27、28、31和32位氨基酸进行随机突变的定点随机突变体库。并在突变体片段两端引入KpnⅠ位点,3′端引入3个氨基酸大小随机连接肽的序列。经KpnⅠ酶切后随机连接,克隆于噬菌粒展示载体pCANTAB5S。克隆产物转化大肠杆菌TG1,辅助噬菌体M13K07拯救,构建噬菌体展示定点随机突变组合文库。结果该定点随机突变组合文库的转化子数目为6.4×106个,滴度为1.4×1015TU/L;文库中含0.72以上的阳性克隆,其中有2个单结构域的阳性克隆占0.15;15个样品的序列分析显示各突变位点和随机连接肽的氨基酸序列呈随机性分布。结论成功构建了噬菌体展示免疫球蛋白结合分子定点随机突变组合文库,该库库容量在一级结构上具有良好的随机性和多样性,可满足体外分子进化研究的要求。  相似文献   

7.
HCV核心蛋白噬菌体随机展示肽库的构建   总被引:3,自引:2,他引:3  
目的 :为了探讨噬菌体展示技术在筛选和鉴定病毒抗原表位研究中的应用前景。 方法 :利用随机引物 PCR法以HCV核心基因为模板合成随机 DNA片段 ,再经特定引物二次扩增后获得高丰度的 HCV核心蛋白随机 DNA片段 ,将该片段插入噬菌粒载体 p CANTAB5 X的 Xba 位点 ,转化大肠杆菌 TG1,辅助噬菌体拯救 ,建立噬菌体随机肽展示文库。结果 :所构建的随机文库含 1.2 3× 10 5个不同克隆 ,库容噬菌体滴度为 2× 10 1 2 TU/ m l(转导单位 / ml) ,PCR法检测插入阳性为 2 8.1% ,核酸杂交证实 40 %的克隆为 HCV核心基因阳性克隆。 结论 :所建的随机文库有足够大的库容和较好的多样性 ,可以满足HCV C抗原表位的筛选。  相似文献   

8.
随机多肽噬菌体展示载体pCANTAB5X的构建   总被引:6,自引:5,他引:6  
构建适用于外源性随机多肽的噬菌体展示载体,方法在引物中加入XbaⅠ识别序列,将用该引物扩增的PCR产物克隆到pGEM-T中,再将该片段插入pCANTAB5E中构建成噬菌体展示载体pCANTAB5X。结果限制酶切点XbaI和HGVC片段被引入到新构建的噬菌粒载体pCANTAB5X中。  相似文献   

9.
目的 应用噬菌体展示技术构建抗重组人肿瘤坏死因子-α(rhTNF-α)的单链抗体库.方法 利用噬菌体表面展示技术、绕过杂交瘤技术,提取经免疫BALB/c小鼠淋巴细胞总RNA,用相应引物扩增小鼠免疫球蛋白VH基因和VL基因,构建VH、VL抗体库.由Linker-primer mix经重叠延伸反应将重链可变区基因与轻链可变区基因拼接成单链抗体.再用RS primer mix以单链抗体为模板进行第二次聚合酶链反应,从而获得全套抗rhTNF-α的单链抗体基因.以SfiⅠ/NotⅠ,位点定向插入pCANTAB-5E噬菌粒载体,转化大肠杆菌TG1后,经M13KO7辅助噬菌体拯救,构建成全套抗rhTNF-α单链抗体表面展示文库.结果 成功构建了rhTNF-α全套单链抗体噬菌体表面展示文库.经M13KO7超感染后,噬斑计数滴度为2.1×1011 pfu.结论 rhTNF-α全套单链抗体噬菌体表面展示文库的构建,为研究rhTNF-α抗体结合位点,了解其结构与功能的关系以及研究用于临床免疫治疗的新型抗体打下了基础.  相似文献   

10.
利用质粒pBI121为载体,通过对其酶切位点的改造,引入一个目的基因(204 bp),构建成一个新的质粒pBI190。方法:用Sac I和Xba I分别对质粒pBI121进行酶切,0.8%低熔点琼脂糖凝胶电泳回收所需片段,将已知DNA片段用引物进行PCR扩增后,使用T4 DNA连接酶将上述得到的DNA片段与酶切回收的质粒pBI121 DNA进行连接。结果:将连接产物转化大肠杆菌DH5α及筛选与测序公司进行鉴定,最终符合目的要求。结论:本实验将质粒pBI121进行了改造,构建了新的表达载体pBI190,并且分析了实验过程中遇到的相关问题。  相似文献   

11.
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   

12.
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   

13.
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   

14.
目的:评价使用安心颗粒对急诊经皮冠状动脉介入术(PPCI)术后生活质量的影响.方法:将160例接受PPCI的急性ST段抬高型心肌梗死患者随机分为安心颗粒组(术前顿服安心颗粒8.8g,术后安心颗粒4.4 g/次,每日2次)和对照组(仅接受基础药物治疗).所有患者均服用阿司匹林、氯吡格雷和阿托伐他汀.分别在入院时、出院前1d、出院后180 d时,应用心肌梗死多维度量表(MIDAS)、中文版SF-36评价量表对患者生活质量评分.并观察术后30 d以内的出血并发症、血小板减少症发生情况.结果:入院时和出院前1d,两组患者的心肌梗死MIDAS、SF-36量表评分比较无差异(P>0.05);出院后180 d时,与对照组比较,安心颗粒组MIDAS、SF-36评分明显减低(P<0.05);组内与入院时比较,两组出院前1d、出院后180 d时,MIDAS、SF-36评分均降低(P<0.05).两组患者在随访期间均无大量出血、少量出血、重度和极重度血小板减少症发生,安心颗粒组有4例、对照组有7例发生不明显出血(P>0.05).两组发生轻度血小板减少症的患者数比较无差异(P>0.05).结论:PPCI使用安心颗粒,能改善急性ST段抬高型心肌梗死患者的生活质量,且不增加出血风险.  相似文献   

15.
Objective:To investigate the influences of urapidil and nicardipine on rabbit sinus function,atrio-ventricular node function and hemodynamics.Methods:Thirty-two Angora's rabbits were selected and randomly divided into four groups.U1 group:urapidil 0.25 mg/kg;U2 group:urapidil 0.5 mg/kg;N1 group:nicardipine 10 μg/kg;N2 group:nicardipine 20 μg/kg.All these medicine were administrated within 30 seconds.Measurements were taken before and after the administration of urapidil or nicardipine for the following data:mean blood pressure(MAP),heart rate(HR),sino-atrial conduction time(SACT),maximal sinoatrial recovery time(SNRTmax)corrected sinus node recovery time(CSNRT),index of sinus node recovery time(SNRTI),Wenckebach A-V conduction frequency (WB),and P-R interval.Results:Significant MAP and HR changes were identified in all of the four groups before and after administration of both urapidil and nicardipine.No significant changes could be found in the rest of the parameters.Intergroup analysis showed that SACT and CSNRT of N1 and N2 groups were shorter than those of the U2 group(P<0.01);the MAP decreased(P<0.01)and the HR increased drastically(P<0.01).Conclusions:Neither urapidil(0.25 mg/kg,0.5 mg/kg)nor nicardipine(10μg/kg,20μg/kg)has any significant influence on rabbit sinus function or rabbit atrio-ventricular node function.Nicardipine could be a better choice than urapidil for parafunctional sinus node patients.  相似文献   

16.
Objective:To investigate the gene expression of osteoprotegerin(OPG) and osteoclast differentiation factor(ODF) in the bone tissue of patients with hip fracture due to osteoporosis. Methods:OPGmRNA and ODFmRNA in the bone tissue in 50 cases of osteoporosis sufferers(over 50 years old) with hip fracture(Observer Group) and 30 cases of hip facture sufferers with no osteoporosis(Control group) were analyzed with the Semi-Quantitative RT-PCR method. Results:The mRNA expressed of ODF, OPG were both high in the patients with hip fracture. In the control group, the expression of OPG mRNA was observed, while the expression of ODF mRNA was very slight. Conclusion:Aged patients contained all signals including OPG, ODF that are essential for inducing osteoclastogenesis and promoting bone resorption.  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.
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   

19.
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   

20.
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   

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