水溶性亲和超滤载体的制备和应用

用Ｄｅｘｔｒａｎ Ｔ２０００,经环氧氯丙烷交联并氧化产生部分羧基,偶联对氨基苯甲脒制得水溶性亲和载体巨配基。配基密度为７１．４μｍ ｏｌ／ｇ。截留分子量为１０ 万的超滤膜对所制亲和载体的截留率大于９９．５％ ,但尿激酶能自由通过。将比活为５００ＩＵ／Ａ２８０的尿激酶粗品经亲和超滤得到纯化的尿激酶,比活达６６ ３００ＩＵ／Ａ２８０,纯度提高１３３ 倍,回收率达８３．４％ 。     

Chitosan Conduit for Peripheral Nerve Regeneration

ＩｎｔｒｏｄｕｃｔｉｏｎＴｒａｎｓｅｃｔｉｏｎｉｎｊｕｒｅｄｐｅｒｉｐｈｅｒａｌｎｅｒｖｅｈａｓａｌｗａｙｓｂｅｅｎｄｉｆｆｉｃｕｌｔｔｏｒｅｐａｉｒ .Ｃｌｉｎｉｃａｌｍｅｔｈｏｄｓｉｎｃｌｕｄｅｅｐｉｎｅｕｒｉｕｍｓｕｔｕｒｉｎｇ (ｕｓｅｄｆｏｒｓｌｉｇｈｔｌｙｉｎｊｕｒｅｄｎｅｒｖｅｓ)ａｎｄａｕｔｏｇｒａｆｔ (ｕｓｅｄｆｏｒｓｅｖｅｒｅｌｙｌａｃｅｒａｔｅｄｎｅｒｖｅｓ) .Ｕｎｆｏｒｔｕｎａｔｅｌｙ ,ｂｏｔｈｍｅｔｈｏｄｓｈａｖｅｄｉｓａｄｖａｎｔａｇｅｓｓｕｃｈａｓｎｅｒｖｅｄｉｓｔｏｒｔ…     

Affinity Capillary Electrophoresis:Study of the Binding of HIV-1 gp41 with a Membrane Protein (P45) on the Human B Cell Line,Raji

ＩｎｔｒｏｄｕｃｔｉｏｎＳｉｎｃｅｔｈｅｄｉｓｃｏｖｅｒｙｏｆＨＩＶ１,ｔｈｅａｅｔｉｏｌｏｇｉｃａｌａｇｅｎｔｏｆＡＩＤＳ［１］,ｔｈｅｒｅｈａｓｂｅｅｎｉｎｃｒｅａｓｉｎｇｉｎｔｅｒｅｓｔｉｎｔｈｅｉｎｔｅｒａｃｔｉｏｎｏｆＨＩＶｅｎｖｅｌｏｐ...     

特异性Tetrodotoxin亲和吸附微珠的制备及其提取性能

将横纹东方豚卵巢与醋酸乙醇溶液混合匀浆,经离心,加热,沉淀,脱脂等处理,制得粗提液,活性炭吸附粗提液得到粗毒液;以壳聚糖为载体合成亲和微珠分别来分离纯化粗提液和粗毒液,用传统的小鼠生物法检测TTX毒素量．潮湿活性炭对TTX的吸附量约为2μg／g,潮湿亲和微珠吸附量约为10μg／g;亲和微珠吸附提取粗毒液,回收率达51％,直接吸附粗提液,回收率达到80％,同时蛋白也得到有效的去除．     

Planktonic copepod community of a reef zone in the southern Gulf of Mexico

ABSTRACT

In this study, the variation of seasonal and inter-annual density and diversity of the copepod community in the Parque Nacional Sistema Arrecifal Veracruzano (PNSAV) was analysed. Samples were collected under nortes, rainy and dry weather conditions in 2011, as well as under nortes and dry weather conditions in 2012 and 2013 in four transects. Surface trawls with 330-μm conical nets were made. The temperature, salinity and dissolved oxygen were measured in situ. The values obtained were 23.07 ± 0.53 to 29.29 ± 0.27°C for temperature, 33.43 ± 0.49 to 35.91 ± 0.09 for salinity, and 2.52 ± 0.08 to 6.56 ± 0.08 mg l^?1 for dissolved oxygen. The copepods collected belonged to 19 families, 28 genera and 62 species. Copepods represented between 69.74% and 76.79% of the abundance of crustaceans present in zooplankton. The highest number of copepods occurred under nortes weather conditions in 2011 with 401,885 ± 28,092 copepods/100 m³ of the species Temora stylifera. In 2012, 256,325 ± 76,872 copepods/100 m³ of the species Paracalanus aculeatus were obtained and in 2013, 311,526 ± 76,872 copepods/100 m³ of the species T. turbinata. The highest specific richness was found in the southern zone with 28 species. In 2013 the highest density was found in the northern zone with 100,323 ± 28,888 copepods/100 m³. The highest diversity was found under dry weather conditions in 2011 with 3.71 bits/individual. In the 3 years of study, 24 species were dominant; 12 of these, appeared in the 3 years of sampling: T. stylifera, T. turbinata, Labidocera scotti, P. aculeatus, O. latus, Pontellopsis villosa, Centropages velificatus, Parvocalanus crassirostris, Corycaeus speciosus, Undinula vulgaris, Oithona plumifera, and Farranula gracilis. Canonical correlation analysis showed the formation of five groups explained by the neritic or oceanic affinity of the species and their tolerance to changes in salinity or temperature.     

酵母培养液中胰蛋白酶初探

利用鸡卵黏蛋白对于胰蛋白酶有天然抑制性的特点,从鸡蛋清中分离纯化了鸡卵黏蛋白,将其偶联至Sepharose 4B制作成亲和层析介质,用于从不同种类酵母,处于不同时间段的培养液中,分离纯化得到了具有胰蛋白酶活性的物质。由此初步证明了酵母培养液中确有可能存在胰蛋白酶。因此,利用酵母工程菌生产蛋白质的时候,若加入一定量的胰蛋白酶抑制剂,有可能提高目的蛋白的产率。     

用作亲和色谱固定相基体的二氧化锆与脲醛树脂复合物微球的合成

文中研究了一种用作生物大分子亲和色谱基体的二氧化锆与脲醛树脂复合物微球的制备方法。以水合氯化氧锆为起始原料,六次甲基四胺和尿素作为沉淀剂,在正庚烷乳液中生成 3～ 5μm的二氧化锆与脲醛树脂复合物微球。探讨了乳化剂和乳化助剂的种类、比例、搅拌速度等对复合物微球球径的影响。     

Formation of the B cell synapse: retention or recruitment?

Interaction of B cells with membrane antigen results in the formation of the B cell synapse: the B cell receptor (BCR) and antigen concentrate in the contact zone while CD45/B220 and the phosphatase SHP-1 are excluded. This study shows that, unlike in T cells, synapse formation does not require active transport processes (while subsequent antigen extraction and IgM downregulation do). The synapse architecture depends on the available protein ligands in the contact zone. Thus Syk, IgM and Fc receptor accumulation require the presence of ITAM-bearing BCRs, membrane antigen and membrane (IgG-containing) immune complexes, respectively. Remarkably, non-bound proteins are frequently not only homogeneously distributed but excluded from the contact zone. These results suggest that proteins mainly reach the contact zone by undirected diffusion, and in order not to be expelled by molecular crowding they require capture by and fixation to a binding protein.Received 25 August 2004; received after revision 2 November 2004; accepted 17 November 2004     

血红蛋白变异体(β15Trp→Leu)的功能与结构

目的 :用基因工程菌制造血红蛋白变异体 (β15Trp→Leu) ,并测定其生物功能 ,探讨血红蛋白分子结构与功能的关系 .方法 :通过对质粒pHE7的DNA分子操作用中性氨基酸Leu取代β15Trp ,利用层析分离技术等把血红蛋白变异体从基因工程菌中提取纯化出来 ,在确定其为目标蛋白质后进行稳定性、亲氧力与协同变构效应能力的测定 ,并对变异体生物功能特性进行分子结构的分析 .结果 :血红蛋白变异体 (β15Trp→Leu)结构稳定 ,与正常血红蛋白比较 ,亲氧力增强 ,协同变构效应能力下降 .结论 :β15Trp在血红蛋白分子结构中相当重要 ,由其与对应的氨基酸所形成的氢键与蛋白分子的生物功能关系密切 ,该氢键的失去使血红蛋白改变正常功能 ,亲氧力增强 ,协同变构效应能力下降 .     

小鼠噬菌体抗体库的构建和N-肽结合单链抗体的筛选

成功构建一库容量为1.7×10⁸的小鼠噬菌体抗体库,并从中淘选出对N-肽有结合活性的单链抗体。首先从未免疫小鼠的脾脏中提取总RNA,分离出mRNA,经逆转录合成其总cDNA。随后通过PCR分别扩增出抗体重链和轻链可变区V_H、V_L的基因片断,再经重组PCR将两片断由一编码(Gly₄Ser)₃十五肽的接头连在一起,并克隆到噬菌质粒pCANTAB 5E中,电击转化大肠杆菌TG1。经辅助噬菌体M13KO7超感染回收全部重组噬菌体,此即噬菌体抗体库。N-肽是一种新发现的神经肽,其N端与阿片肽高度同源,可与阿片肽受体相互作用。对其研究可能有助于了解成瘾机制和有临床应用价值。将生物素化的N-肽与抗体库相互作用,用偶联有链霉亲和素的磁珠富集与N-肽结合的重组噬菌体,经四轮淘选,得到亲和力较高的单链抗体。