［B3－Lys］－胰岛素的研究：受体结合及生物活性

本文用１２５Ｔ－［Ｂ３－Ｌｙｓ］－胰岛素和１２５Ⅰ－胰岛素研究了［Ｂ３－Ｌｙｓ］－胰岛素和胰岛素与人胎盘细胞膜（ＨＰＭ）胰岛素受体结合特性并进行了比较。实验结果表明［Ｂ３－Ｌｙｓ］－胰岛素与ＥＰＭ胰岛素受体结合能力比天然猪胰岛素高。由竞争取代曲线得到的［Ｂ３－Ｌｙｓ］－胰岛素和猪胰岛素的ＩＣ（５０）值分别为０．６５和１．１１ｎｍｏｌ／Ｌ。经Ｓｃａｔｃｈａｒｄ分析得出［Ｂ３－Ｌｙｓ］－胰岛素与ＨＰＭ胰岛素受体中高亲和位点和低亲和位点结合的亲和常数分别为１．７２×１０９和２．２７×１０６Ｌ／ｍｏｌ,而猪胰岛素分别为１．２６×１０９和１．４７×１０６／ｍｏｌ。促脂肪细胞合成脂肪实验结果表明［Ｂ３－Ｌｙｓ］－胰岛素也同样具有比天然猪胰岛素更高的离体生物活力,ＥＣ（５０）分别为０．１７５和０．３０１ｎｍｏｌ／Ｌ。可见［Ｂ３－Ｌｙｓ］－胰岛素的受体结合能力和高体生物活力都为猪胰岛素的１．７倍。     

烟草多酚氧化酶的分离与固定化技术研究

多酚氧化酶属于氧化还原酶类,国际酶学委员会推荐名为儿茶酚氧化酶（ＥＣ１．１０．３．１ｐｏｌｙｐｈｅｎｏｌｏｘｉｄａｓｅ,ＰＰＯ）．该酶与食品工业、三废处理、医药卫生关系较为密切,因而研究较多．如近年来鸭梨［１］、蘑菇［２］、香蕉果肉组织［３］、荔枝果皮［４］等等中的多酚氧化酶均有研究报道．目前研究用固定化多酚氧化酶检测废水中酚类物质含量,进行环境检测;及其从工业废水中除去酚类,达到治理三废的目的．Ｍｏｓｂａｃｎ［５］（１９７６）研制成多酚氧化酶固定化酶柱,与氧电极检测器组合联用,可检测水中２０…     

[B3—Lys]—胰岛素的研究：受体结合及生物活性

本文用＾１２５Ｉ－［Ｂ３－Ｌｙｓ］－胰岛素和＾１２５Ｉ－胰岛素研究了［Ｂ３－Ｌｙｓ］－胰岛素和胰岛素与人胎盘细胞膜胰岛素受体结合物性并进行了比较。实验结果表明［Ｂ３－Ｌｙｓ］－胰岛素与ＨＰＭ胰岛素受体结合能力比天然猪胰岛素高。由竞争取代曲线得到的［Ｂ３－Ｌｙｓ］－胰岛素和猪胰岛素的ＩＣ（５０）值分另为０．６５和１．１１ｎｍｏｌ／Ｌ。经Ｓｃａｔｃｈａｒｄ分别得出［Ｂ３－Ｌｙｓ］－胰岛素与ＨＰＭ胰岛素     

棉属海岛棉×拟似棉F_1不育性研究

本文研究了棉属海岛棉［ＧｏｓｓｙｐｉｕｍｂａｒｂａｄｅｎｓｅＬ．,（ＡＤ）２］ｘ拟似棉［Ｇ．ｇｏｓｓｙｐｉｏｉｄｅｓ（Ｕ１ｂｒ）Ｓｔａｎｄｌｅｙ,Ｄ６］Ｆ_１植株的减数分裂及不育花粉的形成过程。Ｆ_１花粉母细胞在减数分裂中期Ｉ平均染色体构型为２４．８６Ⅰ＋６．９８Ⅱ＋０．０５Ⅲ。Ｆ_１不育的根本原因在于减数分裂中期染色体不能正常配对,引起部分染色体滞后及染色体不均等分配,从而产生多分孢子和微核,最终导致不育花粉的产生,并讨论Ｄ６与（ＡＤ）２间的亲缘关系以及克服Ｆ_１不育的方法。     

信阳地区柑橘凤蝶生物学特性

柑橘凤蝶ＰｏｐｉｌｉｏｘｕｔｈｕｓＬｉｎｎａｅｕｓ为鳞翅目、凤蝶科昆虫［１］。在信阳地区幼虫寄主植物主要为柑橘Ｃｉｔｒｕｓｒｅｔｉｃｕｌａｔａ、野花椒Ｚａｎｔｈｏｘｙ－ｌｕｍｓｉｍｕｌａｍｓ、枳Ｄｏｎｃｉｒｕｓｔｒｉｆｏｌｉａｔａ等芸香科植物,成虫黄绿与黑色相间组成美丽的花纹,是具有观赏价值的大型凤蝶之一［２］。为开展柑橘凤蝶人工饲养,作者于１９９６～１９９７年对其形态、习性、生活史等生物学特性进行了研究,现将研究结果报告如下。１材料与方法１．１材料柑橘凤蝶种源：野外采集成蝶,笼内产卵获得。饲养…     

中国智麦蛾属二新种记述(鳞翅目：麦蛾科)

智麦蛾属ＳｏｐｈｒｏｎｉａＨüｂｎｅｒ主要分布于欧洲、亚洲和北美,少数分布至南非［１］。全世界已记载２０余种,已知寄主多为菊科Ｃｏｍｐｏｓｉｔａｅ植物。Ｅ．Ｍｅｙｒｉｃｋ（１９３６）报道Ｓｏｐｈｒｏ－ｎｉａｉｌｕｓｔｒｅｌａ（Ｈüｂｎｅｒ,１７９６）...     

微核仁是富含剪接因子SC35的核内小体

许多植物细胞核中存在一些较小的球形或卵圆形的结构,不同作者分别将其称为球体（ｓｐｈｅｒｕｌｅｓ）［１］、核体（ｋａｒｙｏｓｏｍｅ）［２］、核仁附着小体（ｎｕｃｌｅｏｌｕｓａｓｏｃｉａｔｅｄｂｏｄｉｅｓ）［３］、螺旋小体（ｃｏｉｌｅｄｂｏｄｉｅｓ）［４...     

丽腹弓角鳃金龟的发生与防治

丽腹弓角鳃金龟ＴｏｘｏｓｐａｔｈｉｕｓａｕｒｉｖｅｎｔｒｉｓＢａｔｅｓ属鞘翅目,鳃金龟科（Ｍｅｌｏｌｏｎｔｈｉｄａｅ）,是西藏分布广泛,对农作物为害严重的一种多食性昆虫［１～３］。自１９９５年起,经过调查,基本摸清了其在我区的分布、为害情况、生活习性及防治措施。１分布及危害丽腹弓角鳃金龟在西藏主要分布在林芝、昌都、山南、拉萨和日喀则等地区。其为害区主要在海拔３８００ｍ以下的山地、河谷地带,特别是在靠近河边的地带危害最为严重。该虫主要危害苹果、梨、红豆草、蚕豆等植物幼嫩的叶片。在林芝危害日趋严重,…     

小麦谷氨酸脱羧酶的纯化及部分性质研究

谷氨酸脱羧酶（ｇｌｕｔａｍａｔｅｄｅｃａｒｂｏｘｙｌａｓｅ,ＧＡＤ,ＥＣ４．１．１．１５）催化谷氨酸脱羧生成γ－氨基丁酸（γ－ａｍｉｎｏｂｕｔｙｒａｔｅ,ＢＡ）,植物中已从南瓜［１］、马铃薯和林生山黧豆［２］纯化了ＧＡＤ．ＧＡＤ活性在禾本科作物中作为...     

巯基修饰对中华仓鼠二氢叶酸还原酶的激活

脊椎动物二氢叶酸还原酶（ＤＨＦＲ,Ｅ．Ｃ．１．５．１．３）可被多种因素激活,如中性无机盐［１］、蛋白质变性剂［１～４］、巯基修饰剂［１,４～７］等．来源于鸡肝［５］、猪肝［６］、鼠肝［７］及鼠Ｌ１２１０细胞［４］二氢叶酸还原酶的巯基修饰激活已有报道．...     

长爪沙鼠产后发育中线粒体产能

本文通过产后1日龄到3O日龄长爪沙鼠肝脏和棕色脂肪组织的线粒体研究揭示,肝线粒体在出生后的呼吸速率、氧化磷酸化作用以及细胞色素氧化酶活力均达到恒定水平。肝线粒体蛋白质量随胎后发育日龄而增加,直至2O日龄左右,琥珀酸氧化酶活力在此时也增加到近于恒定,因此肝线粒体产能发育随日龄增长到2O日龄右。这可能是长爪沙鼠体温调节发育的细胞机制之一。从棕色脂肪线粒体的细胞色素氧化酶和琥珀酸氧化酶活力的变化,显示棕色脂肪组织在长爪沙鼠新生幼仔阶段产热中所起的重要作用。     

大肠杆菌合成的乙型肝炎病毒核心抗原(HBcAg)转化为e抗原(HBeAg)的探索

本文以带有HBcAg基因重组质粒的大肠杆菌转化株Ecoli MM206所合成的HBcAg进行HBcAg转化为HBeAg的探索研究。菌经超声破碎获得的菌裂解液对生理盐水透析两天后,酶联检测发现抗原性部分转化为HBeAg。将菌裂解液或HBcAg精制品用2-巯基乙醇处理,可使抗原性发生进一步转化。但是分子筛层析证明抗原蛋白分子大小没有明显变化。这种制品有可能作为诊断试剂用以检测抗-HBe,而且实验结果表明HBeAg是由HBeAg衍变来的。为要提高HBeAg的稳定性,以碘乙酰胺处理,使还原的抗原蛋白通过羧甲基化反应封闭游离的巯基。经上述处理的HBeAg通过分子筛层析可与大部分细菌杂蛋白分开,制品只有HBeAg活性而测不到HBeAg活性,因而提高了抗原蛋白的稳定性与纯度。     

Kinetic analysis of demetalation of bacteriochlorophyll c and e homologs purified from green sulfur photosynthetic bacteria

Substituent-dependent demetalation kinetics of natural bacteriochlorophyll (BChl) c and e homologs purified from two green sulfur photosynthetic bacteria was first studied. Separated BChl e homologs, which possessed a formyl group at the 7-position of their chlorin macrocycles, exhibited a significantly slow removal of central magnesium to free-base bacteriopheophytins in acidic aqueous acetone compared with the corresponding BChl c homologs, which possessed a methyl group at the 7-position. Additional methyl groups at the 8(2)-position of both BChl c and e molecules had little effect on the demetalation kinetics.     

Development of hematological respiratory variables in late chicken embryos: the relative importance of incubation time and embryo mass

Oxygen demand increases during embryonic development, requiring an increase in red blood cells (RBCs) containing hemoglobin (Hb) to transport O(2) between the respiratory organ and systemic tissues. A thorough ontogenetic understanding of the onset and maturation of the complex regulatory processes for RBC concentration ([RBC]), Hb concentration ([Hb]), hematocrit (Hct), mean corpuscular indices (mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration ([MCHb])) is currently lacking. We hypothesize that during the last half of incubation when the respiratory organ (the chorioallantoic membrane) envelops most of the egg contents, mean corpuscular indices will stabilize. Accordingly, Hct, [RBC] and [Hb] must also all change proportionally across development. Further, we hypothesize that the hematological respiratory variables develop and mature as a function of incubation duration, independently of embryonic growth. As predicted, a similar increase in Hct (from 18.7±0.6% on day 10 (d10) to 34.1±0.5% on d19 of incubation), [RBC] (1.13±0.03×10(6)/μL to 2.50±0.03×10(6)/μL) and [Hb] (6.1±0.2 g% to 11.2±0.1 g%) occurred during d10-19. Both [RBC] and [Hb] demonstrated high linear correlation with Hct, resulting in constant [MCHb] (~33 g% from d10 to d19). The decrease in MCV (from ~165 μ(3) on d10 to ~140 μ(3) on d13) and MCH (~55 pg to ~45 pg) during d10-13, may be attributed to a changeover from larger primary to smaller secondary and adult-type erythrocytes with MCV and MCH remaining constant (~140 μ(3) and ~45 pg respectively) for the rest of the incubation period (d13-19). Hematological respiratory values on a given incubation day were identical between embryos of different masses using either natural mass variation or experimental growth acceleration, indicating that the hematological variables develop as a function of incubation time, irrespective of embryo growth.     

Recapture of [S]-allantoin, the product of the two-step degradation of uric acid, by urate oxidase

Urate oxidase from Aspergillus flavus catalyzes the degradation of uric acid to [S]-allantoin through 5-hydroxyisourate as a metastable intermediate. The second degradation step is thought either catalyzed by another specific enzyme, or spontaneous. The structure of the enzyme was known at high resolution by X-ray diffraction of I222 crystals complexed with a purine-type inhibitor (8-azaxanthin). Analyzing the X-ray structure of urate oxidase treated with an excess of urate, the natural substrate, shows unexpectedly that the active site recaptures [S]-allantoin from the racemic end product of a second degradation step.     

Role of cell signaling in B[a]P-induced apoptosis: characterization of unspecific effects of cell signaling inhibitors and apoptotic effects of B[a]P metabolites

Here we show that several cell signaling inhibitors have effect on cyp1a1 expression and the metabolism of benzo[a]pyrene (B[a]P) in Hepa1c1c7 cells. The CYP1A1 inhibitor alpha-naphthoflavone (alpha-NF), the p53 inhibitor pifithrin-alpha (PFT-alpha), the ERK inhibitors PD98059 and U0126, and the p38 MAPK inhibitors SB202190 and PD169316 induced the expression and level of cyp1a1 protein. On the other hand, during the first h the inhibitors appeared to reduce the metabolism of B[a]P as measured by the generation of tetrols and by covalent binding of B[a]P to macromolecules. In contrast, the phosphatidylinositol-3 (PI-3) kinase inhibitor wortmannin, had neither an effect on the cyp1a1 expression nor the B[a]P-metabolism. In order to avoid these unspecific effects, we characterized the mechanisms involved in the apoptotic effects of B[a]P-metabolites. B[a]P and the B[a]P-metabolites B[a]P-7,8-DHD and BPDE-I induced apoptosis, whereas B[a]P-4,5-DHD had no effect. B[a]P, B[a]P-7,8-DHD and BPDE-I induced an accumulation and phosphorylation of p53, while the Bcl-2 proteins Bcl-xl, Bad and Bid were down-regulated. Interestingly, the levels of anti-apoptotic phospho-Bad were up-regulated in response to B[a]P as well as to B[a]P-7,8-DHD and BPDE-I. Both p38 MAPK and JNK were activated, but the p38 MAPK inhibitors were not able to inhibit BPDE-I-induced apoptosis. PFT-alpha reduced the BPDE-I-induced apoptosis, while both the PI-3 kinase inhibitor and the ERK inhibitors increased the apoptosis in combination with BPDE-I. BPDE-I also triggered apoptosis in primary cultures of rat lung cells. In conclusion, often used cell signaling inhibitors both enhanced the expression and the level of cyp1a1 and more directly acted as inhibitors of cyp1a1 metabolism of B[a]P. However, studies with the B[a]P-metabolite BPDE-I supported the previous suggestion that p53 has a role in the pro-apoptotic signaling pathway induced by B[a]P. Furthermore, these studies also show that the reactive metabolites of B[a]P induce the anti-apoptotic signals, Akt and ERK. Neither the induction nor the activity of p38 MAPK and JNK seems to be of major importance for the B[a]P-induced apoptosis.