妊娠相关蛋白A的纯化及鉴定研究

目的:对比G200凝胶过滤、反向亲和层析、DEAE离子交换等不同的方法纯化孕妇血清中的妊娠相关蛋白A(PAPP-A),为下一步的临床应用研究奠定基础。方法:把正常男性血清过G200凝胶过滤纯化后免疫家兔得到兔抗人抗体,连接溴化氰活化G25凝胶制备反向免疫层析柱。收集足月孕妇血清,离心后依次应用G200凝胶过滤、反向亲和层析及离子交换层析柱纯化。用ELISA检测试剂盒检测各个洗脱峰的PAPP-A活性,SDS-PAGE检测纯化蛋白的纯度。结果:稀释兔抗人血清抗体至浓度为1∶16,双向扩散有明显沉淀线,可以用于制备抗体,蛋白A亲和层析洗脱pH3.0洗脱峰,G200凝胶过滤第一个洗脱峰,反向亲和层析的0.1 mol/LPBS洗脱峰,离子交换层析的0.45 mol/L NaCl洗脱峰中PAPP-A活性均较高。SDS-PAGE结果显示,孕妇血清用G200凝胶过滤处理后杂蛋白条带较多,反向亲和层析或者DEAE分别处理后同样存在杂蛋白条带,三种纯化方法结合应用杂蛋白条带明显减少,Western blot鉴定显示三种方法结合应用后纯化蛋白样品条带单一。结论:本研究用三种层析方式相结合的方法得到纯度较高的PAPP-A抗原,鉴定显示可以到达制备单克隆抗体(mAb)的要求,为mAb的制备以及酶联免疫试剂盒的建立奠定了基础,使PAPP-A在临床应用方面前景广阔。     

人survivin蛋白的原核表达、纯化及抗原活性鉴定

目的 构建人肿瘤抗原survivin的原核表达载体,优化在大肠杆菌中的表达条件,并对survivin/His融合蛋白进行纯化和抗原活性鉴定.方法 设计针对survivin基因序列的特异引物,通过聚合酶链式反应(PCR)扩增人survivin全长基因序列(538 bp)克隆至原核表达载体pET28a(+),构建重组表达载体pET28 a-survivin,并将该载体转化大肠杆菌BL21(DE3),经IPTG诱导表达survivin/His融合蛋白,并采用Ni亲和层析凝胶纯化重组蛋白.纯化后的重组蛋白经Western blot法、ELISA鉴定其抗原活性.结果 重组表达载体经BamH Ⅰ和HindⅢ鉴定正确;IPTG诱导后经SDS-PAGE分析表明获得了相对分子质量(Mr)24000大小的重组蛋白;纯化后的蛋白纯度达到90％.Western blot法和ELISA检测证实纯化的survivin蛋白能够与特异性抗体发生反应,表明其具有良好的抗原活性.结论 成功构建了原核表达载体pET28 a-survivin,利用大肠杆菌表达系统实现了融合蛋白的可溶性表达并进行纯化,纯化后survivin蛋白经鉴定具备较高的抗原活性.     

CAD基因原核表达载体的构建及表达产物的活性鉴定

目的 构建pCool-GST-ICAD/CAD的表达载体,并在大肠杆菌BL21(DE3)中表达具有生物学活性的CAD核酸酶.方法 用PCR扩增CAD基因, 将扩增产物克隆入pCool-GST-ICAD载体中构建出pCool-GST-ICAD/CAD表达载体.经酶切和电泳鉴定正确后,在大肠杆菌BL21(DE3)中诱导表达,表达产物经亲和层析、离子交换层析及凝胶过滤等方法分离纯化,最后用SDS-PAGE和DNA降解实验进行鉴定.结果 构建了pCool-GST-ICAD/CAD原核表达载体,重组载体转化后表达出毫克级水平的GST-ICAD/CAD蛋白复合体.经分离纯化后得到纯度很好的CAD-ICAD蛋白复合体,在SDS-PAGE电泳上呈现清晰的两条蛋白带.经DNA降解实验证明纯化所得的CAD蛋白具有非特异性降解DNA的核酸酶作用.结论 成功制备了具有生物学活性的CAD核酸酶,为进一步研究细胞凋亡的作用机制提供了有效的制剂.     

截短型BAP31/GST基因重组质粒的构建及融合蛋白的表达、纯化和鉴定

目的构建编码截短型肿瘤抗原BAP31(△BAP31)与GST融合基因的原核表达载体,在大肠杆菌中表达并对融合蛋白(△BAP31/GST)进行纯化和初步鉴定。方法 PCR扩增编码△BAP31的基因片段,上下游分别引入EcoR I及Xho I酶切位点,亚克隆至含有GST标签的原核表达载体pGEX4T-1中,构建重组表达载体pGEX4T1-△BAP31,将该载体转化大肠杆菌DH5α,IPTG诱导表达△BAP31/GST,用GST亲和层析分离纯化原核表达的△BAP31/GST,表达产物分别用SDS-PAGE和West-ern blot进行鉴定。结果重组质粒经限制性内切酶EcoR I和Xho I双酶切鉴定和IPTG诱导表达△BAP31/GST的SDS-PAGE分析表明,表达产物的相对分子质量为40 000,与理论值相符,并主要以可溶性蛋白形式存在;经过对融合蛋白表达条件的优化,在IPTG浓度为1 mmol/L,诱导6 h目的蛋白表达量最高;灰度扫描分析发现,融合蛋白表达量占菌体蛋白总量的70.6%,纯化产物的纯度最高可达94.5%,Western blot证实该△BAP31/GST可与抗GST单克隆抗体(mAb)发生特异性结合反应,分子量为△BAP31与GST分子量之和,提示为融合蛋白。结论成功构建了编码△BAP31基因原核表达载体pGEX4T1-△BAP31,利用大肠杆菌表达系统和GST亲和层析,获得了较高纯度的△BAP31/GST融合蛋白,为进一步研究肿瘤抗原BAP31的功能及开发以BAP31作为靶点的肿瘤疫苗提供了试验基础。     

重组葡激酶-人HC蛋白融合蛋白的原核表达、纯化及鉴定

目的:表达和纯化重组葡激酶-人HC蛋白融合蛋白,并初步鉴定其生物学活性.方法:利用重叠延伸PCR方法使基因重组获得目的基因片段,插入带有GST标签的原核高效可溶性表达载体pEGX-6P-1中,构建重组表达质粒pEGX-6P-1-SAK-HC,将重组表达质粒转化大肠杆菌B834,经IPTG诱导目的蛋白表达;对融合蛋白用谷胱甘肽琼脂糖凝胶柱(GST)亲和层析柱及DEAE离子交换柱纯化,用PreScission蛋白酶切除GST标签,SDS-PAGE分析该融合蛋白的表达量和纯度,应用纤维蛋白平板溶圈法测定评价其生物学活性.结果:构建的重组表达质粒经PCR、内切酶鉴定及基因序列测定证实,目的蛋白在大肠杆菌中获得表达,SDS-PAGE显示相对分子质量(Mr)为36000;对表达产物进行了亲和层析纯化,从上清中获得了纯度较高的葡激酶-人HC蛋白融合蛋白,体外实验显示其纤溶活性为9.4×104 IU/mg.结论:获得了可溶性的葡激酶-人HC蛋白融合蛋白,且其纤溶活性与尿激酶标准品相当.为下一步进行融合蛋白免疫原性鉴定奠定了基础.     

人源抗狂犬病毒二硫键稳定抗体在大肠杆菌中的融合表达

目的在大肠杆菌pMAL-P2x系统中表达anti-rabiesMBP-ScdsFv融合蛋白,酶切获得目的蛋白ScdsFv,进行纯化、鉴定及简单活性分析。方法利用DNA重组技术,将全长的ScdsFv蛋白基因克隆至原核表达载体pMAL-p2x中,重组质粒转化大肠杆菌E.coliER2566,IPTG诱导表达。表达产物经Xa酶切后,经Ni柱、AmyloseResin亲和层析进行纯化,SDS-PAGE和Western blot对其进行鉴定,ELISA检测其结合活性。结果成功地构建了重组质粒pMAL-ScdsFv,经诱导表达、蛋白酶切、亲和纯化后获得目的蛋白。ELISA检测其具有抗原特异结合活性,其热稳定性有显著提高。结论抗狂犬病毒ScdsFv蛋白具有良好的结合活性和生物学活性稳定性,可作为候选分子用于狂犬病的防治研究。     

Golph2蛋白质的原核表达及多克隆抗体制备

目的:新近发现Golph2蛋白与肝癌关系密切,制备Golph2重组蛋白质和多克隆抗体,建立Western blot检测技术,为后续研究提供基础.方法:RT-PCR从人肝癌细胞株WBF44钓取Golph2基因序列,PCR回复突变制备全长完整基因(1 206 bp),将其插入至原核表达载体pET-21、转化大肠杆菌DH5a,IPTG诱导表达,镍柱亲和层析纯化蛋白,SDS-PAGE鉴定.将纯化蛋白质免疫家兔,制备多克隆抗血清.建立Western blot 鉴定重组蛋白和抗血清特异性,测定临床血清标本中Golph2蛋白水平.结果:从肝癌细胞中钓取的基因,出现2个碱基置换突变和1个碱基缺失突变,经回复突变,获得与NM 177937完全一致序列.SDS-PAGE和Western blot证实,重组Golph2蛋白质与预期结果一致.抗血清能够特异地识别52 kD重组蛋白质和73 kD血清蛋白质.结论:Golph2蛋白质表达和抗血清制备完全成功,可以用于后续研究     

构建pCool-GST-ICAD/CAD并在大肠杆菌中表达CAD核酸酶及活性研究

目的：构建pCool-GST-ICAD/CAD的表达载体，并在大肠杆菌BL21(DE3)中表达具有生物学活性的CAD核酸酶。方法：用PCR扩增CAD核酸酶基因,将扩增产物克隆入pCool-GST-ICAD载体中构建出pCool-GST-ICAD/CAD表达质粒。经酶切和电泳鉴定正确后，在大肠杆菌BL21(DE3)中诱导表达，表达产物经亲和层析、离子交换层析及凝胶过滤等方法分离纯化，最后用SDS-PAGE和DNA降解实验进行鉴定。结果：构建了pCool-GST-ICAD/CAD原核表达质粒，重组载体转化后表达出毫克级水平的GST-ICAD/CAD蛋白复合体，经分离纯化后得到纯度很好的CAD/ICAD蛋白复合体，在SDS-PAGE电泳上呈现清晰的两条蛋白带，经DNA降解实验证明纯化所得的CAD蛋白具有非特异性降解DNA的核酸酶活性。结论：成功构建具有生物学活性的CAD核酸酶，有助于进一步研究细胞凋亡的作用机制。     

博尔纳病毒核蛋白的原核表达、纯化及鉴定

目的 构建、表达、并纯化重组博尔纳病毒核蛋白(Borna disease vires,BDV),并鉴定该蛋白.方法 通过PCR反应从博尔纳病毒cDNA中扩增博尔纳病毒核蛋白P40基因,构建博尔纳病毒核蛋白P40基因重组质粒pET-14b-BD-VP40,转化大肠杆菌,IPTG诱导融合蛋白的表达,His-tag亲和层析纯化该蛋白,SDS-PAGE分析其表达量、表达形式和纯度;Western-blot法鉴定该蛋白.结果 成功构建蓖组质粒pET-14b-BDVP40,酶切鉴定、核酸序列分析正确,亲和层析纯化后纯度可达90%,Western-blot表明重组蛋白能与博尔纳病毒核蛋白单克隆抗体特异性结合.结论 在大肠杆菌中成功表达了可溶性的pET-14b-BDVP40融合蛋白,为进一步研究博尔纳病毒核蛋白作用机制及开发相应血清学检测试剂盒提供基础.     

人核糖体蛋白S13的原核表达、纯化及多克隆抗体的制备

目的克隆人核糖体蛋白S13(ribosomal protein S13,RPS13)cDNA全长,构建原核表达质粒,诱导表达、纯化RPS13蛋白并制备其多克隆抗体。方法应用RT-PCR方法从胃癌多药耐药细胞SGC7901/VCR中扩增出RPS13的cDNA全长,利用DNA重组技术构建重组原核表达载体pET-28a( )-RPS13,双酶切及测序鉴定。将重组载体转化入大肠杆菌BL21中,筛选抗性克隆并经DNA测序证实。IPTG诱导融合蛋白的表达,利用镍离子亲和层析柱提纯融合蛋白,经SDS-PAGE和Western blot鉴定。用纯化的融合蛋白His-RPS13免疫BALB/c小鼠,ELISA法测定抗体效价,饱和硫酸铵沉淀法纯化抗体,Western blot检测抗体活性。结果RT-PCR扩增片段与预计目的基因片段大小一致;双酶切鉴定表明,重组表达载体pET-28a( )-RPS13构建成功,DNA测序结果显示所获基因序列与GenBank中收录完全相同。IPTG诱导3h后,经SDS-PAGE检测显示在Mr19000处出现一新生条带,与预计的融合白大小一致;利用抗His标签的抗体进行Western blot,结果证实融合蛋白表达成功。其免疫血清经Western blot证实可特异性的识别蛋白RPS13。结论成功地获得了RPS13的编码基因序列,并获得了纯化的RPS13蛋白质,为制备RPS13的单克隆抗体、进一步研究RPS13在肿瘤中的作用奠定了基础。     

Photoperiodicity and the function of the hypophysis and the adrenal cortex

Summary The ACTH content of the hypophysis of rats rises from a minimum in the morning to a maximum in the evening hours. These fluctuations are associated with the diurnal rhythm of light and darkness, and are abolished under conditions of continual light or darkness for 30 days. Rhythmic fluctuations of the ascorbic acid content of the adrenals are also found, with maximum values in the evening, and these are likewise abolished by maintenance under conditions of constant illumination.Presented by Active Member AMN SSSR V. V. Parin     

Organization and distribution of the upper and lower esophageal motoneurons in the medulla and the spinal cord of the rat

The upper cervical esophagus is exerted on swallowing and peristalsis by somatic and visceral motoneurons, whereas the lower esophagus is exerted on only peristalsis by visceral motoneurons. We examined the origin of the esophageal motoneurons and whether there were any differences between the distributions of the upper and the lower esophageal motoneurons in the medulla and the spinal cord using cholera toxin subunit b (CTb) as the retrograde tracer. Following injection of CTb into the cervical esophagus resulted in heavy labeling of the neurons in the nucleus ambiguus including the compact (AmC), semicompact (AmS) and loose (AmL) formations, and the medial column of lamina IX at the C1-C5 levels of the cervical spinal cord corresponding to the spinal accessory nucleus. A few labeled neurons were found in the inferior salivatory nucleus, the rostral division of the dorsal motor nucleus of the vagus (DMX), the accessory facial nucleus and the lateral column of lamina IX at the C2 and C3 levels. All these labeled neurons showed ChAT immunoreactivity. When CTb was injected into the cut end of the unilateral recurrent laryngeal nerve, many labeled neurons were found in the ipsilateral AmC, the AmL, and the bilateral medial column at the C1 and C2 levels. Following injection of CTb into the subdiaphragmatic esophagus resulted in heavy labeling of the neurons only in the AmC and the DMX. When CTb was injected into the sternomastoid muscle, many labeled neurons were found in the medullary reticular formation, the facial nucleus, the medial column at the C1-C3, C5 and C6 levels, and the lateral column at the C2, C3, C5 and C6 levels. Injections of a Fluoro-Gold into the cervical esophagus and a CTb into the sternomastoid muscle or the subdiaphragmatic esophagus in the same animal showed many double labeled neurons in the medial column of the accessory nucleus at the C1 and C2 levels, but no double labeled neurons in the AmC. These results indicated that the upper cervical esophagus is innervated by the visceral medullary vagal motoneurons as well as the somatic spinal accessory motoneurons. The lower esophagus is innervated only by the visceral medullary vagal motoneurons.     

Anatomic considerations and the relationship between the piriformis muscle and the sciatic nerve

Stating background  The piriformis syndrome is one of the non-discogenics causes of sciatica. It results from the compression of the sciatic nerve (SN) by the piriformis muscle (PM) in the neutral and piriformis stretch test position. The evidence of the increase in pain in the test position requires a detailed anatomical study addressing the changes that occurred in the SN and PM anatomy during the test position. The aim of this study is to examine this relationship morphometrically. Materials and methods  A total of 20 right and left lower limbs of ten adult cadavers were examined. The SN and the PM were made visible. The location of the SN was evaluated with respect to the consistent bony landmarks, including the greater and the lesser trochanter of the femur, the ischial tuberosity, the ischial spine of the hip bone, the posterior inferior iliac spine of the hip bone and the posterior superior iliac spine of the hip bone. The study was done in both neutral and test positions (i.e., 30° adduction 60° flexion and approximately 10° medial rotation position of the hip joint). Results  The width of the greater sciatic notch was 63.09 ± 13.59 mm. The length of the lower edge of the PM was 95.49 ± 6.21 mm, and whereas the diameter of the SN where it emerged from the infrapiriforme was 17.00 ± 3.70 mm, the diameter decreased to 11.03 ± 2.52 mm at the level of the lesser trochanter of the femur. The SN intersected the PM most commonly in its medial second quarter anatomically. The vertical distance between the medial edge of the SN–PM intersection point and the ischial tuberosity was 85.62 ± 17.23 and 72.28 ± 7.56 mm (P < 0.05); the angle between the SN and the transverse plane was 66.36° ± 6.68° and 71.90 ± 8.48° (P < 0.05); and the vertical distance between the medial edge of the SN and the apex of the ischial spine of the hip bone was 17.33 ± 4.89 and 15.84 ± 4.63 mm (P > 0.05), before and after the test position, respectively. Conclusion  This study provides helpful information regarding the course and the location of the SN. The presented morphometric data also revealed that after stretch test position, the infrapiriforme foramen becomes narrower; the SN becomes closer to the ischial spine of the hip bone, and the angle between the SN and the transverse plane increases. This study confirmed that the SN is prone to be trapped in the test position, and diagnosis of this situation requires dynamic MR and MR neurography study.     

空肠和回肠直动脉及器官表面动脉的观测

目的　通过对空、回肠直动脉分支类型的观察、测量不同类型直动脉管径、间距以及器官表面动脉吻合网面密度 ,探讨空、回肠血供形态的异同 ,为临床空、回肠疾病手术、器官移植、介入治疗提供形态学依据。方法　选取 15具成人及 2～ 6岁小儿 10具进行股动脉插管、乳胶灌注后解剖剥离直动脉 ,将空回肠均分 5段观测相关指标。结果　成人空肠 (1、2段 )及回肠 (3～ 5段 )直动脉起始处外管径 (mm)分别为 0 6 8± 0 18、0 72± 0 0 1、0 6 1± 0 0 2、0 5 3± 0 0 3和 0 5 1± 0 0 1,相邻分支间距 (mm)分别为 2 89± 1 72、2 79± 2 0 6、2 2 1± 1 6 4、2 17± 1 17及 2 85± 0 4 6 ;空、回肠直动脉长、短干型分支供血能力不同 ;空肠器官表面动脉吻合网面密度大于回肠。结论　直动脉分支类型、管径、间距及器官表面动脉吻合网面密度对空、回肠血供影响较大。