Growth hormone signal transduction

Growth hormone (GH) promotes animal growth by stimulating bone and cartilage cell proliferation, and influences carbohydrate and lipid metabolism. Some of these effects are brought about indirectly via somatomedin induction in hepatocytes, others by acting directly on the target cells. In either case, GH first binds to specific receptors on cells to trigger a sequence of biochemical events culminating in a biological response. Recently much has been learnt about the molecular structure of GH receptor, its binding to ligand, and the ensuing signal transduction events.     

HEp-2细胞MPM-2磷蛋白的蛋白质组学分析

MPM-2磷蛋白家族成员在有丝分裂进程中起着重要作用．为了从MPM-2磷蛋白家族层面入手研究细胞周期调控中磷蛋白的重要作用，以人上皮样喉癌细胞株HEp-2为细胞模型，运用双向电泳、免疫印迹以及质谱技术等蛋白质组学的方法对其细胞抽提物中的部分MPM-2磷蛋白进行了分析鉴定，初步确定了乙二醛酶(GlyoxalaseⅠ)、真核翻译起始因子(eIF4B)以及核质蛋白NPM等MPM-2特异识别的细胞磷蛋白，这将有助于进一步研究MPM2磷蛋白家族成员在细胞周期调控中的重要作用．     

Loss of antibody production accompanied by chromosome loss in a cloned hybrid line secreting antibodies to sheep red blood cells

Summary Somatic cell hybrids between Sp2/O-Ag14 mouse myeloma cells and lymphocytes derived from BALB/c mice hyperimmunized with sheep red blood cells (SRBC) were produced. One hybrid producing IgG₁ antibody to SRBC was selected, cloned twice and subsequently transferred to BALB/c mice. After a number of transfers it was found that the antibody titer in ascitec fluid gradually decreased. Cytogenetic analysis revealed gradual chromosome loss in the hybrid clone, which produced progressively less antibody.     

抗人绒毛膜促性腺激素（HCG）单克隆抗体的研制和特性分析

以HCG为抗原,免疫BALB/c小鼠,取其脾细胞与小鼠Sp2/0—Ag14骨髓瘤细胞融合,经反复筛选和再克隆化,获得8株能稳定分泌抗HCG特异单克隆抗体的杂交瘤细胞株。对其中6个高效价单抗进行了特异性和抗原决定簇检测,选出两个抗相距较远不同决定簇的单抗(2D_4,4F_4)作进一步特性分析。结果显示:免疫球蛋白亚类鉴定,2D_4为IgGl亚类,4F_4为IgG2a亚类;亲和力常数(K_(affi)),2D_4为5.41±0.94×10~(-10)mol/L,4F_4为1.37±0.33×10~(-9)mol/L。证实该两种单克隆抗体可用于研制有关临床诊断试剂盒。     

细胞分裂素对大豆叶片衰老过程中蛋白激酶基因表达的影响

利用真核生物催化丝氨酸／苏氨酸残基磷酸化的蛋白激酶ＶＩ和Ⅷ保守区设计兼并引物,进行ＲＴ－ＰＣＲ扩增反应,研究大豆叶片衰老过程中蛋白激酶基因表达的变化及外源细胞分裂素处理的作用。结果表明人工合成的细胞分裂素－６ＢＡ预处理很可能在转录水平上正向调节一些蛋白激酶基因的表达,而诱导衰老处理则起负调控作用。     

Studies of a key protein in the mechanism of the excitation-contraction coupling process of frog skeletal muscle,using phenylglyoxal

The excitation-contraction (E-C) coupling process in single twitch fibres from frog toe muscle was inhibited selectively by phenylglyoxal (PGO), a specific guanidyl modifying reagent. A new protein (31.5 kDa), which has PGO-binding ability and seems to play a key role in the E-C coupling process, was solubilized from transverse tubule membrane-junctional sarcoplasmic reticulum complexes (TTM-JSR) of frog skeletal muscles, using¹⁴C-PGO. The monoclonal antibody against this protein applied extracellularly inhibited the E-C coupling process of the single fibres. This protein appears to constitute the very first step of input for E-C coupling. It is considered to behave as an indispensable part of an electrometer to measure membrane potentials. Therefore, the name electrometrin is suggested for the new protein.     

Identification of antiviral- relevant genes in the cultured fish cells induced by UV-inactivated virus

~~Identification of antiviral- relevant genes in the cultured fish cells induced by UV-inactivated virus~~     

视黄醇结合蛋白基因的研究发展

视黄醇结合蛋白(Retinol-Binding Proteins，RBP)是一类维生素A的运载蛋白，参与血清和细胞内视黄醇／酸的转运，是疏水小分子结合蛋白家族的成员。RBP主要在肝脏中合成并释放入血液进而进入各种组织，通过与视黄醇、前白蛋白及细胞表面受体相互作用，在维生素A的储存、代谢、转运到周围靶器官中具有重要功能。细胞内视黄醇结合蛋白则主要在细胞内发挥类似作用。本文主要就血清及细胞内视黄醇结合蛋白的基因结构、作用机理、发育性表达、组织定位及染色体定位、对动物繁殖性能和胚胎发育的影响等方面进行综述。     

抗HBsAg单链抗体的等电点测定和结构模拟

应用实验生物学和计算生物学方法对重组人源抗HBsAg单链抗体(HBscFv)的部分理化性质和空间结构进行分析．首先应用蛋白质分析软件包Antheprot预测HBscFv等电点，然后等电聚焦测定HBscFv等电点，在此基础上，用神经网络法预测HBscFv二级结构，然后用同源建模的方法，获得HBscFv三级结构．结果发现，HBscFv等电点理论值为8．51，实验值为7．3～8．1；PHDsec结果表明，HBscFv是一种全β蛋白质；三级结构建模表明，HBscFv的VH结构域由9个片层组成，VL结构域由8个片层组成；由于单链抗体的特殊性，三级结构建模无法给出VH与VL结构域之间进一步折叠后形成的结构。     

抑制羧肽酶A催化活性的单克隆抗体的制备及性质测定

以羧肽酶Ａ为抗原，经动物免疫、细胞融合、筛选及３次克隆化培养，获得了一株稳定分泌对羧肽酶Ａ肽酶活性有抑制作用的单克隆抗体的杂交瘤细胞株１Ｇ１０。染色体数目为８０～９０；ＥＬＩＳＡ测定腹水效价为１０６；亲和常数为１．５９×１０９（ｍｏｌ／Ｌ）－１；免疫球蛋白属ＩｇＧ１型；分子量为１５０Ｋｄ。羧肽酶Ａ与该抗体反应后测定肽酶活性，显示出该抗体能抑制羧肽酶Ａ的肽酶活性，Ｄｉｘｏｎ法作图表明类似竞争性抑制反应，测得其表观抑制常数为１．１７×１０－７ｍｏｌ／Ｌ。该抗体可能针对羧肽酶Ａ的活性中心部位，为制备具有抗原内影像作用的抗独特型抗体酶打下了基础