大麦G－带变动性以及与染色粒的一致性分析

以大麦为材料,进行了Ｇ－带带纹变动性分析以及Ｇ－带与减数分裂粗线期染色粒的比较。有丝分裂早中期至中期两个不同时期Ｇ－带带纹总数减少３６％,染色体组的绝对长度缩短２５％,带数减少的幅度大于染色体长度缩短的幅度。染色体组中每条染色体之间带纹减少的比例不尽相同,变幅在０．２９－０．５０之间。不同染色体绝对长度减少的幅度在０．２７－３．７０μ之间。从早中期至中期,每单位染色体绝对长度带数具相对减少的趋势。选择第６染色体进行的比较显示,减数分裂的染色粒与有丝分裂的Ｇ－带带纹之间具有很好的对应关系,Ｇ－带带纹和染色粒间的数目、位置和着色程度上都具一致性。对Ｇ－带性质和植物中Ｇ－带的应用等问题进行了讨论。     

Probing the structure and mobility of Pseudomonas aeruginosa azurin by circular dichroism and dynamic fluorescence anisotropy.

The UV dynamic fluorescence and CD of several Pseudomonas aeruginosa azurins bearing single amino acid mutation have been studied. Two classes of mutants were examined. In the first class, two hydrophobic residues in the core of the protein, Ile 7 and Phe 110, nearest to the azurin single tryptophan Trp 48, were substituted by a serine (mutants 17S and F110S). In the second class, two residues in the outer sphere of the copper ligand field were changed, obtaining the following mutants: M44K, H35F, H35L, and H35Q. All these proteins showed two fluorescence lifetimes in the copper-containing form, but only one in the copper-free form. The lifetime of the latter derivatives was different from either those of the metal-bound samples, definitely ruling out the presence of apo-like species in the holo protein. Copper-free 17S and F110S showed a more complex fluorescence decay profile requiring a distribution of lifetimes rather than a single lifetime. Holo F110S was also better fitted, in the limit of confidence, with two distributions rather than a pair of lifetimes. Time-resolved anisotropy of these two mutants as well as of wild-type (wt) protein showed two components (rotational times for wt < or = 200 ps and 7 ns, respectively). These components were not affected significantly by copper removal in the case of wt protein. Instead, the short rotational component of the mutants dropped dramatically to values near zero, indicating a much greater mobility of the tryptophanyl residue in the mutant apo azurins. These data were supported by CD measurements showing a small effect of the copper presence in the region below 250 nm, i.e., in the secondary structure, but almost a collapse of the aromatic asymmetry at 270-295 nm related to a relaxation of the structural constraint around the tryptophan. Altogether these data show that copper does not play a structural role in wt azurin, whereas it is crucial in the stabilization of 17S and F110S mutants. Furthermore, although the metal site geometry is rigidly kept in wt apo-azurin, it regains the native form only in the presence of the metal in the "core" mutants. This finding is important for the theory of entatic states in metalloproteins (Williams RJP, 1995, Eur J Biochem 234:363-381).     

An efficient synthesis of methyl tetra-o-hexyl gentiooctaoside, an octaosyl analogue of ANP receptor antagonist HS-142-1

Methyl

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, a 3-O hexyl analogue of the octaosyl component of fungal lipooligosaccharide HS-142-1, was stereo- and regioselectively synthesized as a potent antagonist for the tetrameric atrial natriuretic peptide (ANP) receptors.     

细叶马先蒿根系发育形态学研究

细叶马先蒿为玄参科多年生草本植物。年生产周期明显缩短。根系营养生长至花期为粗壮主根与纤细侧根并存,果期侧根几乎全部枯萎脱落,所存留根系皆呈乳白色。由胚根形成的初生主根根毛密集,初生木质部二原型。侧生分生组织只有形成层而无木栓形成层。根表皮细胞经解离后略呈不规则方形片状,横切面为平周长梭形,进行垂周分裂增加梭形根表皮细胞长度,以适应根的增粗生长。根表皮脱落时,外皮层以同样生长方式代替脱落的表皮。在年     

丝氨酸蛋白酶抑制剂的研究及应用

丝氨酸蛋白酶抑制剂（serpin）是一类结构、序列同源的蛋白酶抑制剂,它是体内许多蛋白水解级联反应的调节因子,其遗传性结构或分泌异常将导致许多疾病．因此对于其结构及作用机理的研究将为临床应用提供依据．     

两阶抽样中比率型估计量的平均精度

本文给出了两阶抽样中总体均值的比率型估计量的平均精度,它当样本容量充分大时主项不劣于无偏估计量的平均精度．     

特种油料植物的种质资源研究

本文对特种油料植物的种质资源研究进行综述,这些植物包括含长链脂肪酸的Crambe,Limnanthes,Lunaria,短链脂肪酸的Cuphea,Lauraceae,羟基脂肪酸的Lesquerella,环氧脂肪酸的Vernonia,Stokesia,以及液体蜡酯的simmondsia等科、属的植物。     

固定化酵母细胞生产1,6-二磷酸果糖研究

本文研究了固定化酵母细胞制备果糖1,6二磷酸(FDP)的方法及其生产。用卡拉胶包埋方法固定化酿酒酵母(Sacchromyces cerevisae),对含葡萄糖1.0M,磷酸盐0.8M的糖磷液,pH6.5,在37℃下进行磷酸化反应。反复分批转化20天以上,可达到平均产FDPH_427.58mg/ml,最高为59.94mg/ml。用100ml固定化细胞生物反应器连续运转309h,稀释速率D=0.097h~(-1),平均产FDPH_4 21.51mg/ml。20L反应器连续运转,生产能力达到1.7g/h.L。用层析方法制备FDPNa_3结晶粉,提取收率为72.08％,制备质量达到或超过了国内外同类产品的质量要求。     

生物制品检定动态管理系统的开发和应用

掌握生物制品的检定动态是质量管理的重要内容,由于检定周期随着制品种类、批数及检定条件的变化而变化,以往靠手工方式查阅繁杂的检定记录,难以随时快速、全面了解当时的检定状况。检定动态管理软件的开发可应用计算机自动跟踪显示检定进度和检定状态,及时反映制品质量和检定条件变化,明显提高了生产和质量管理部门的工作效率。