Effects of isaxonine phosphate and analogs on fibroblast metabolism in culture

Summary Human skin fibroblasts in confluent cultures were incubated for 24 h in the presence of isaxonine phosphate (Nerfactor) and several related factors. The incorporation of¹⁴C-proline into secreted proteins and the release of collagen into the medium were inhibited. When the cells incubated for an additional period of 24 h after thorough washing, protein and collagen syntheses were found to be identical to those of controls, demonstrating that the inhibition of protein synthesis was independent of any toxic effect. When cells were incubated in the presence of both isaxonine and colchicine, the secretion of collagen was more inhibited than by colchicine alone, and proteins accumulated in the cells.     

Congenital muscular dystrophy: molecular and cellular aspects

The congenital muscular dystrophies are a clinically and genetically heterogeneous group of neuromuscular disorders. Each form has a characteristic phenotype, but there is overlap between some entities and their classification is based on a combination of clinical features and the primary or secondary protein defect. Recent studies have identified the genetic basis of a number of congenital muscular dystrophies (11 genes in total) and have recognised a novel pathological mechanism that highlights the importance of the correct posttranslational processing of proteins, in particular -dystroglycan. Diagnosis of these conditions has been aided by the availability of specific antibodies for each protein and a better understanding of the protein changes that accompany each condition. In this review we present the major molecular, clinical and diagnostic aspects of each group of congenital muscular dystrophy with an emphasis in the more recent developments.Received 11 December 2004; accepted 15 December 2004     

Effects of ovariectomy on removal of collagen bundles in the postpartum uterus of the mouse

Ovariectomy before and after parturition did not influence the rate of postpartum involution and did not affect the removal of collagen bundles in the endometrium during the first three postpartum days.     

重组竹抗压与抗拉力学性能的分析

以慈竹制作的重组竹为研究对象,对重组竹抗压与抗拉力学性能进行了研究,并将重组竹与落叶松等6种木材的力学性能进行了比较。结果表明:重组竹顺纹抗拉强度为248.15 MPa,顺纹抗压强度129.17 MPa,稳定性能较好。通过与落叶松、云杉等木材比较发现,重组竹的抗压和抗拉强度较高,纵向与横向抗压强度差异较小,EL/ET比值小,不同方向的泊松比和强重比也有差别。重组竹的横纹抗压过程分为3个阶段(弹性阶段、塑性阶段、破坏阶段),最后发生塑性破坏。     

重组锰超氧化物歧化酶工程菌摇瓶发酵条件的优化

通过单因素试验对重组锰超氧化物歧化酶(Recombinant Manganese Superoxide Dismutase,rMn-SOD)工程菌的摇瓶发酵的培养基(碳源、氮源、无机盐)和培养条件(接种量、乳糖浓度、时间、温度、摇床转速、pH值等)进行了初步优化.结果表明,工程菌发酵的优化培养基组分(质量分数)为:1.5%蛋白胨、1.5%酵母提取物、1.0%NaCl、0.4%KH2PO4、0.8%K2HPO4、1.5%(体积分数)甘油、0.2%NH4Cl和5 mmol/L MnCl2.乳糖诱导表达的优化条件为:以5%接种量培养5 h后,加入质量分数为0.25%的乳糖进行诱导表达6 h.当发酵温度为37℃、摇床转速为180 r/min、培养基的初始pH值为7.0时,表达的rMn-SOD的酶活力高.在优化条件下,工程菌的SOD活性达1 969.9 U/mL,比活力达1 081.8 U/mg.     

自发光转录激活子样效应因子的功能分析

目的:对转录激活子样效应因子(TALE)蛋白进行特异性标记.方法:通过分子生物学技术,在TALE蛋白的C-端融合了一种具有优异光学性能的萤光素酶.结果:融合蛋白不仅可对目的 DNA进行特异性识别,还可产生萤光素酶的特征光谱.结论:萤光素酶的融合不影响TALE蛋白的正常功能,其光谱信息有望成为分析TALE蛋白与DNA相互作用的特异性检测信号.     

朱黄青霉α-葡聚糖酶在毕赤酵母中的高效表达

【目的】提高朱黄青霉（Penicillium minioluteum ）α-葡聚糖酶（Dextranase）基因在毕赤酵母（Pichia pastoris）中的表达水平。【方法】根据毕赤酵母的密码子偏爱对酶基因进行优化与合成。优化后的基因片段与载体 pGAPZαA 连接,转化毕赤酵母 KM71 H。【结果】获得组成型分泌表达α-葡聚糖酶的工程菌 KM71 H／pGAPZαA-dex。发酵工艺试验中,摇瓶培养144 h,酶活为153 U／mL。6．8 L发酵罐补料分批培养92 h,酶活达到1218 U／mL。【结论】该工程菌以甘油作为碳源,发酵调控简单,产酶水平较高,具有适用于大规模生产的潜力。     

Tropic1808基因重组蛋白对损伤坐骨神经脊髓细胞凋亡的影响

探讨Tropic1808基因重组蛋白对损伤坐骨神经的新生大鼠脊髓细胞凋亡影响,将新生SD大鼠一侧坐骨神经切断后,用无菌止血海绵包裹断离的神经近侧端,海绵内加入Tropic1808基因重组蛋白,阳性用神经生长因子、阴性用生理盐水作为对照;术后3、6、12h经TUNEL法染色,在光镜、电镜和图像分析系统下,了解L4－L5段脊髓细胞凋亡情况。得到生理盐水组的脊髓出现大量绸亡细胞;Tropic1808基因重组蛋白组凋亡细胞数量较生理盐水组显减少;Tropic1808基因重组蛋白组与神经生长因子组之间凋亡细胞数量的差别无显性意义。说明Tropic1808基因重组蛋白有保护受损神经组织,减少细胞凋亡的作用。     

重组Pichia酵母(Muts)发酵过渡阶段关键酶活分析

重组Pichia酵母表达系统的发酵存在从利用甘油为碳源生长到利用甲醇为碳源表达外源蛋白的发酵表达过渡阶段。Pichia酵母过渡阶段碳源代谢途径关键酶酶活分析表明：甲醇诱导3h AOX2酶活为0,4h时突然增加到0．05U,继续诱导,酶活缓慢增加;在过渡阶段甲醛脱氢酶和6-P-葡萄糖脱氢酶分别增加了6．1倍、2．5倍,而丙酮酸脱氢酶和异柠檬酸脱氢酶分别下降为原酶活的29．4％及16．4％,表明甲醇诱导后甲醇完全氧化代谢途径得到强化,而糖酵解途径和三羧酸循环途径代谢作用减弱。     

重组质粒p434crohis的构建与表达

根据噬菌体４３４ｃｒｏ的基因序列,合成了一对在Ｃｒｏ的Ｃ－末端含有６个Ｈｉｓ密码子的寡核苷酸（６９ｂｐ）,并在其两端设计了ＰｓｔＩ和ＫａｓＩ两个酶切位点。经粘合、退火后将双股寡核苷酸链分别插入ｐ４３４ｃｒｏ（３．３５ｋｂ）质粒的４３８位（ＰｓｔＩ切点）和６３８位（ＫａｓＩ切点）,构建成含４３４ｃｒｏｈｉｓ基因的重组质粒。其表达产物为Ｃ端含有６个Ｈｉｓ的阻遏蛋白４３４ｃｒｏｈｉｓ。经功能测定表明融合蛋白４３４ｃｒｏｈｉｓ仍具有调节ＤＮＡ转录功能,并用金属亲和层析鉴定了表达产物