最简单的反射是单突触反射。由于突触在结构与功能上的特性,决定了反射弧上冲动的传导只能由感受器传向效应器。
固相多肽合成就是不断地在固相载体上加入α-氨基和侧链基团被保护的氨基酸。FMOC基团是用来保护α-氨基中的N的,去除保护基团后,再加入第二个氨基酸。产生的多肽通过一个连接臂将C端连接在树脂上,它可以被裂解下来。通常情况下,在多肽从树脂上裂解下来的同时去除侧链保护基团,一般采用哌啶去FMOC保护基团,肽树脂的裂解和侧链保护基团去除一般用强酸,比如三氟乙酸,N,N-二甲基甲酰胺(DMF)是树脂去保护、氨基酸反应和洗涤的首选溶剂。
细胞中有大约30%的蛋白质是膜蛋白,不过人们现在还不是很清楚这些膜蛋白的原子结构。到目前为止,在PDB(Protein Data Bank)的结构数据库中只有不到1%的资料是膜蛋白的结构数据。这不是说膜蛋白的结构不重要,相反,膜受体蛋白非常重要,它们是大部分药物的作用靶点。但由于一直缺乏很好的膜蛋白大量可溶性表达技术,因此也就得不到足够的蛋白结晶体用于结构分析。即使是结构基因组学(文后小词典)这项旨在分析每一个蛋白家族结构的学科,也因为存在技术难题而没有将研究重点放在膜蛋白上。现在,经过传统结构生物学家和结构基因组学家的不懈努力,蛋白表达、溶解和结晶这一系列的技术瓶颈都得到了突破,并且已经出现了部分成果。
1. 探针的标记:(1) 如下设置探针标记的反应体系:待标记探针 (1.75pmol/微升) 2微升T4 Polynucleotide Kinase Buffer (10X) 1微升nuclease-Free Water 5微升ATP(3,000Ci/mmol at 10mCi/ml) 1微升T4 Polynucleotide Kinase (5-10u/微升) 1微升总体积 10 ...
【原理】 以醋酸纤维薄膜为支持物,用缓冲液润湿后,将微量血清样品点于膜上,再在电泳槽中进行电泳,可将血清蛋白分离成清蛋白、α1、α2、β、γ球蛋白五条区带,将薄膜置于染色液中,使蛋白质固定并染色后,可看到清晰色带,也可将色带分别于碱溶液中进行定量测定,再计算血清中各种蛋白质的含量百分数。 在正常情况下,这些蛋白质各占一定的百分比,在某些病理情况下, ...
This method uses carboxyfluorescein succinimidyl ester (CFSE)rather than fluorescein isothiocyanateresulting in more reliable labeling.Succinimidyl esters are excellent reagents for amine modification ...
Day 0 and 1 Materials 1.0.5 mM ATP0.2 mM CaCl22 mM Tris-HClpH 8.0 at 4℃250 ml for day 0. 2.100 mM KCl100 mM boric acidpH 8.4 at 4℃10 ml. 3.0.5 mM ATP2 mM MgCl2100 mM KCl2 mM DTT2 mM PIPESpH 7.01000 ml ...
Day 0 and 1 Materials 1.0.5 mM ATP0.2 mM CaCl21 mM PIPESpH 6.8 at 4℃250 ml for day 0. 2.0.5 mM ATP0.2 mM CaCl270 mM KCl150 mM PIPESpH 7.01 ml. 3.16 mM ATP0.2 mM CaCl25 mM DTT5 mM lysine10 mM glutamic ...
Day 0 and 1 Materials 1.0.5 mM ATP0.2 mM CaCl22 mM Tris-HClpH 8.0 at 4℃250 ml for day 0 and 1000 ml for day 1. 2.100 mM KCl100 mM boric acidpH 8.4 at 4℃10 ml. 3.IATR (tetramethylrhodamine iodoacetamid ...
Day 0 and 1 Materials 1.0.5 mM ATP0.2 mM CaCl22 mM Tris-HClpH 8.0 at 4℃250 ml for day 0. 2.0.5 mM ATP2 mM MgCl2100 mM boric acidpH 8.3 at 4℃10 ml. 3.N-(1-pyrene)iodoacetamide (Molecular probes P-29m.w ...
Day 1-2 Materials 1.0.5 M KCl10 mM HEPESpH 7.54℃250 ml. 2.0.5 M KCl50 mM HEPESpH 8.04℃250 ml. 3.Bio-Beads SM-2 in a 0.7x15 column. 4.20 mM KCl20 mM PIPESpH 7.04℃250 ml. 5.IATR (tetramethylrhodamine io ...
Day 1 Materials 1.50 mM KCl0.2 mM EGTA2 mM ATP2 mM MgCl210 mM HEPESpH 7.0.Need 500 ml. Procedure 1.Thaw appropriate volume of frozen gizzard myosin to obtain 10-20 mg. 2.Centrifuge in a SS34 rotor at ...
Materials 1.Small vial and stir bar. 2.Bio-Beads SM-2 in 0.7x15 cm column. 3.2 mM Tris-HClpH 8.54℃250 ml. 4.Centricon-30 concentrator. 5.5 mM Tris-acetate0.1 mM DTTpH 6.954℃250 ml. 6.200 mM K-boratepH ...
Materials 1.200 mM K-boratepH 9.010 ml. 2.100 mM lysine100 mM K-boratepH 9.01 ml aliquots stored at -20℃. 3.2 mM Tris-HClpH 8.54℃250 ml. 4.100 mM DTT stock. 5.Centricon-30 concentrator. 6.5 mM Tris-ac ...
Materials 1.Drop frozen 2x cycled tubulin in a polymerization-promoting buffer.Stored at -80℃ 2.GTP100 mM stocktitrate to pH ~7.Need 2 ml. 3.Waterbathset at 37℃ 4.SS34 rotor5 ml and 15 ml tubes and ad ...
Materials 1.2 mM PIPESpH 7.0500 ml. 2.Gc-globulin (Calbiochem 345802)1 mg. 3.CFSE (Carboxyfluorescein succinimidyl ester; Molecular Probes). 4.Lysine100 mM in buffer 110 ml. 5.G25-150 desalting column ...
How long should cells be labeled? The ideal length of time to label cells depends on the protein of interest and the label that you are using.If you want to label an unstable protein with 35S-methioni ...
Recipes for the buffers are at the end of this protocol. 1.Label your protein with 32Pi.Then subject the protein to SDS polyacrylamide gel electrophoresis and transfer your gel-fractionated protein to ...
This specific procedure was developed to assay the activity of the Lck kinase expressed from a retroviral vector in rat fibroblasts.You can obviously use fewer or more cellsdepending on your needs.Don ...
凝胶迁移或电泳迁移率实验(EMSA)是一种研究DNA结合蛋白和其相关的DNA结合序列相互作用的技术,可用于定性和定量分析。这一技术最初用于研究DNA结合蛋白,目前已用于研究RNA结合蛋白和特定的RNA序列的相互作用。通常将纯化的蛋白和细胞粗提液和32P同位素标记的DNA或RNA探针一同保温,在非变性的 ...