以淀粉珠为载体的亲和层析法分离纯化高温α淀粉酶

 以淀粉珠为载体的亲和层析法分离纯化高温α淀粉酶张学忠,宋伦,王群,吴晓霞,唐锌进（吉林大学酶工程国家重点实验室,长春１３００２３;南京师范大学生物系,南京２１００２４）金凤燮等人从酒曲中筛选出高产热稳定α淀粉酶的菌株,命名为Ｂａｃｉｌｌｕｓｓｐ－ＪＦ...     

牛胰多肽（BPP）二级结构的红外光谱和圆二色谱分析

牛胰多肽（ｂｏｖｉｎｅｐａｎｃｒｅａｔｉｃｐｏｌｙｐｅｐｔｉｄｅ,ＢＰＰ）是胰脏分泌的一种含有３６个氨基酸的多肽［１］,ＢＰＰ能预防和治疗由胆酸盐诱发的大鼠急性胰腺炎,具有细胞保护作用。本文用傅里叶变换红外光谱（ＦＴ－ＩＲ）和圆二色谱（ＣＤ）,对ＢＰＰ在水溶液中的二级结构进行了研究。两种方法的分析结果互相补充,进一步确定了ＢＰＰ在溶液状态的二级结构。本研究为进一步探讨ＢＰＰ抑制膜融合的机理打下了基础。     

Epr Studies on the Effects of Complexation of Heme by Hemopexin upon its Reactions with Organic Peroxides

Hemopexin, a heme-binding serum glycoprotein, is thought to play an important role in the prevention of oxidative damage that may be catalysed by free heme. Through the use of EPR techniques, the generation of free radicals from organic hydroperoxides by heme and heme-hemopexin complexes, and the concomitant formation of high oxidation-state iron species has been studied; these species are implicated as causative agents in processes such as cardiovascular disease and carcinogenesis. From the rates of production of these species from both n-alkyl and branched hydroperoxides, it has been inferred that the dramatic reduction in the yield of oxidising species generated by heme upon its complexation with hemopexin arises from steric hindrance of the access of hydroperoxide to the bound heme.     

Production of panose from maltose by intact cells of Aureobasidium pullulans

Panose, a major component of isomalto-oligosaccharides, was selectively produced from maltose using transglucosylation reaction catalyzed by intact cells of Aureobasidium pullulans. When 50 %(w/v) maltose was used as a substrate, the maximum concentration of panose accumulated in the final reaction mixture was about 50 %(w/w) after 120 hr reaction at 55 °C.     

Expression and secretion of human lipocortin-1 by promoter and signal sequence of STA1 from Saccharomyces diastaticus

Summary For the secretion of human lipocortin-1 (LC-1) in yeast, a expression and secretion vector was constructed by using the promoter and signal sequence of glucoamylase gene (STA1) of Saccharomyces diastaticus. After the cDNA of human LC-1 was ligated with the secretion vector, the resulting hybrid plasmid was transformed into S. diastaticus. When the recombinant S. diastaticus was cultivated in YPD medium, LC-1 was expressed and secreted into the extracellular medium, yielding LC-1 protein at a concentration of 2.5 g/mL.     

基因工程链激酶(r—SK)纯化及其单克隆抗体制备和鉴定

采用Rotofor等电聚焦和分子筛技术纯化大肠杆菌表达的重组链激酶(r—SK),其纯度为97%。比活性1×10⁶IU／mg,回收率41％。分析所纯化的r—SK　N端氨基酸顺序证实其1—15个氨基酸顺序与SK基因的核苷酸顺序所示3联密码子一致。以纯化r—SK为抗原,通过杂交瘤技术构建了分泌抗r—SK单克隆抗体(McAb)杂交瘤细胞(4D11),该McAb属IgG1亚型．特异地作用于r-SK和C组口溶血性链球菌分泌的SK。用底物显色法测定该McAb可抑制SK对纤溶酶原的激活。Western blot法证实该McAb能识别分子量为16 250Da的r—SK的CNBr裂解片段。推测SK蛋白中第71残基至第237残基间的氨基酸顺序参与SK与纤溶酶原的结合。     

红旗泡水生植物群落结构与功能的研究

红旗泡是松嫩平原上的水草型湖泊,１９７２年由引嫩干渠补入嫩江水,使其成为大庆市主要水源地和渔业基地。该湖水生植被分布面积大,覆盖近１／２的水面。本文分析了芦苇,狭叶香蒲和稗等单优群落的结构与分布,并统计了混合群落的数量特征。随着油田开发,大庆地区的水体均受到不同程度的污染;因红旗泡水生植物资源丰富且其具清除油污、吸附重金属和沉降悬浮物等净化功能,故使其成为大庆地区水质最好和鱼产量最高的湖泊。