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81.
大瓶螺碱性磷酸酶的分离纯化及部分性质研究李清漪,曾和期(西南师范大学生物系,重庆630715)碱性磷酸酶(EC3.1.3.1,简称AKP)是广泛存在于动物组织中的水解酶。对软体动物中AKP的研究仅有少数报道[1,2],对属于单壳贝类的水生食用螺──大... 相似文献
82.
DNaseⅠ超敏感位点的研究能够发现潜在的调控基因转录活化的位点,比较正常人外周血有核细胞,淋巴瘤细胞株P3HR1和人鼻咽癌低分化磷癌细胞株HOnE1和HNE2中Ha-ras-1瘤基因的DNaseⅠ超敏感位点发现,只有HONE1和HNE2细胞基因组中存在一个DNaseⅠ超敏感位点,位于第一个外显子上游0.37kb处,上述结果提示正常白细胞和P3HR1细胞中Ha-ras-1基因处于失活状态,而在鼻咽癌细胞基因组中则处于活化状态,它的活化可能与0.37kb处的DNA序列有密切的关系。 相似文献
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85.
Martin M. Lee Francis H.Y. Green W.Michael Schoel Samuel Schürch 《生物化学与生物物理学报:疾病的分子基础》1994,1226(2):151-162
Cell-substrate adhesion was quantified for two cultured mesothelioma cell lines (epitheliomatus and sarcomatous) on glass, fibronectin and laminin substrates. Interference reflection microscopy (IRM) was used to image the adhesion patterns of cells and a grey level analysis was employed to quantify adhesion. Sarcomatous cells demonstrated marked adhesion to glass and fibronectin-coated substrates but not to laminin-coated substrate, with the greatest adhesion occurring on the fibronectin-coated surface. This adhesion was accompanied by cytoplasmic spreading. By contrast, epitheliomatous cells showed little tendency to adhere to any of the substrates and only showed significant spreading when in contact with the laminin substrate (P < 0.01). A bioassay was used to determine the metastatic potential of each of the cell lines. Via the intravenous route, the sarcomatous cells killed the host rats in 24.7 ± 1.5 (S.D.) days compared to 27.3 ± 0.9 (S.D.) days for the epitheliomatous cells (P < 0.01). After subcutaneous inoculation of tumour cells, the sarcomatous cells killed the host rats in 54.7 ± 0.7 (S.D.) days compared to 48.5 ± 0.5 (S.D.) days for the epitheliomatous cells (P < 0.01). We conclude that the results of the metastasis bioassays were consistent with the predicted behavior of these cell lines based on their ability to adhere to substrates in the in vitro adhesion assays. 相似文献
86.
本文提取人骨骼肌α辅肌动蛋白(α-actinin)是综合了文献报导有关提取兔肌α-actinin的和提取鸡胗α-actinin的方法,稍加修改而确定的。用Hasselbach-Schneider缓冲液提取骨骼肌中的肌球蛋白后,将残余物经硼酸-缓冲液提取、匀浆及高速离心去掉肌动蛋白和肌原纤维的其它成份,上清加硫酸铵至30%,35%饱合度所得的沉淀用220mmol/LTris-乙酸溶解、透析、离心后经DE-52柱层析可得电泳纯。α-actinin。将人骨骼肌α-actinin纯化制品免疫了三只大耳白纯种家兔,两个多月后,三只兔子都产生免抗人骨骼肌α-actinin的特异抗血清,用双向免疫扩散法和酶联免疫吸附试验(ELISA)测定,产生的抗体效价较高,用双扩散法测定效价为1:32,用ELISA测定,用比率法判断结果,效价最高者为1:100,000左右,经免疫电镜观察结果证实,上述抗血清可以满足进一步实验要求。 相似文献
87.
本文报导了胰腺提取物中两种可被钙/钙调素依赖性蛋白激酶磷酸化的热稳定蛋白。SDS-PAGE测定其表观分子量分别为17.7kD和6kD。经钙/钙调素依赖性蛋白激酶磷酸化后,其最大磷酸参入量为8.8μmol/g蛋白。同时磷酸化作用导致17.7kD蛋白在SDS-PAGE中迁移率发生变化。本文还进一步分析了各种阳离子对磷酸化的影响,并对此两种蛋白可能具有的生理功能进行了初步探讨。 相似文献
88.
Arlene D. Acevedo Samuel S. Bowser Mary E. Gerritsen Rena Bizios 《Journal of cellular physiology》1993,157(3):603-614
Subconfluent bovine pulmonary artery endothelial cells on rigid substrates were exposed to 1.5–15 cm H2O sustained hydrostatic pressure for up to 7 days and exhibited elongation, cytoskeletal rearrangement, increased cell proliferation, and bilayering. The role of basic fibroblast growth factor (bFGF) in the mechanism(s) of these endothelial cell responses to sustained hydrostatic pressure was investigated. Evidence that bFGF was released from endothelial cells exposed to sustained hydrostatic pressure or compression was provided by the following experimental results: (1) Cells exposed to control (3 mm H2O) pressure displayed intense nuclear and cytoplasmic bFGF staining by immunocytochemical techniques; this staining was absent in cells exposed to 10 cm H2O for 7 days. (2) Conditioned medium from endothelial cells exposed to 10 cm H2O for 7 days contained at ansferable, growth-promoting activity exhibiting heparin-Sepharose affinity, lability to both heat and freeze/thawing, and neutralization by anti-bovine bFGF. (3) Suramin (0.1 mM), a growth-factor receptor inhibitor, abrogated the proliferative and morphological responses of endothelial cells exposed to sustained hydrostatic pressure. Endothelial cells exposed to elevated hydrostatic pressure demonstrated no detectable decrement in cell viability as assessed by Trypan blue exclusion. The results of the present study indicate that hydrostatic pressure or compression can induce bFGF release from endothelial cells independent of cell injury or death; bFGF is subsequently responsible for the morphological, proliferative, and bilayering responses of endothelial cells to hydrostatic pressure. © 1993 Wiley-Liss, Inc. 相似文献
89.
We have characterized, by electron probe microanalysis, rapidly frozen cultured rat islets at the level of individual secretory granules. Elemental analysis of thin, dried cryosections showed that beta granules could be distinguished by high Zn, Ca, and S, whereas non-beta (mainly alpha) granules contained elevated P and Mg. Although a single granule type predominated in a particular cell, some rebel granules were found in A cells that had the compositional fingerprint of B cell granules. Zn, which was found in millimolar concentrations in B cell granules, was considered a marker for the insulin storage complex. The data indicate that non-B islet cells in the adult pancreas may produce insulin-containing organelles and that, when glucagon and insulin are coexpressed, these hormones are packaged in separate granules. 相似文献
90.