1,6—二磷酸果糖产生菌的筛选及最佳培养条件的研究

１,６－二磷酸果糖（ＦＤＰ）广泛应用于治疗心血管疾病。本文进行了１,６－二磷酸果糖产生菌的筛选和最佳条件的研究。筛选出菌株ＨＹ２具有较高的产１,６－二磷酸果糖酶活力,高达１６０ｍｇＦＤＰ／ｇ ｗｅｔ ｃｅｌｌｓ,菌体生长的最适培养条件为：麦芽汁培养基糖度为１２柏林,培养温度为２８℃,ｐＨ６．０￣６．５,菌体收率达７．０％左右。     

蛇肌果糖1，6－二磷酸酯酶、果糖2，6－二磷酸、AMP的结合部位关系

腺苷－磷酸（ＡＭＰ）对４个快反应巯基被修饰的蛇肌果糖１,６－二磷酸酯酶活性的抑制作用增强,而该修饰的酶受果糖２,６－二磷酸的抑制脱敏。ＡＭＰ对酶抑制为半部位反应,酶受果糖２,６－二磷酸抑制的脱敏则表现为全部位反应。经枯草杆菌蛋白酶限制性酶解的果糖１,６－二磷酸酯酶的Ｋｉ（ＡＭＰ）增大１０倍,但受果糖２,６－二磷酸抑制的性质不变。经胰蛋白酶限制性酶解的果糖１,６－二磷酸酯酶的活性不再为ＡＭＰ抑制,但果糖２,６－二磷酸对该形式酶的抑制作用则明显增强,由于该酶失去受ＡＭＰ的抑制作用,因此ＡＭＰ促进果糖２,６－二磷酸抑制的性质亦随之丧失。据此提出在蛇肌果糖１,６－二磷酸酯酶中果糖２,６－二磷酸不是结合在ＡＭＰ结合部位上的看法。     

蛇肌果糖1,6—二磷酸酯酶,果糖2,6—二磷酸,AMP的结…

腺苷一磷酸对４个快反应巯基被修饰的蛇肌果糖１,６－二磷酸酯酶活性的抑制作用增强,而该修饰的酶受果糖２,６－二磷酸的抑制脱敏,ＡＭＰ对酶抑制为半部位反应,酶受果糖２,６－二磷酸抑制的脱敏则表现为全部位反应,经枯草杆菌蛋白酶限制性酶解的果糖１,６－二磷酸酯酶的Ｋ１增大１０倍,但受果糖２,６－二磷酸抑制的性质不变,经胰蛋白酶限制性酶解的果糖１,６－二磷酸酯酶的活性不再为ＡＭＰ抑制,但果糖２,６－二磷酸对     

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１,６二磷酸的方法及其生产。用卡拉胶包埋方法固定化酿酒酵母,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ＦＤＰＨ４ ２７．５８ｍｇ／ｍｌ。最高为５９．９４ｍｇ／ｍｌ。     

蛇肌果糖1，6－二磷酸酯酶果糖2，6－二磷酸和底物抑制的结合部位

在果糖１,６—二磷酸酯酶中果糖２,６—二磷酸可能与底物抑制的作用方式不同,因为蛇肌果糖１,６－二磷酸酯酶ｐＨ９．２的活性受到果糖２,６－二磷酸的抑制,而不受高浓度底物的影响。Ｋ＋能增强果糖２,６—二磷酸对酶活性抑制,并能较大程度地解除过量底物的抑制。快反应流基修饰酶不再受较低浓度果糖２,６—二磷酸的抑制,但高浓度果糖２,６—二磷酸仍能抑制酶活性,其ＩＣ５０增大４０倍。修饰酶受底物抑制的阈值不变。为胰蛋白酶或枯草杆菌蛋白酶限制性酶解的果糖１,６—二磷酸酯酶受过量底物和果糖２,６—二磷酸抑制的行为也不相同。以上结果可能提示在蛇肌果糖１,６—二磷酸酯酸中存在既有别于ＡＭＰ,又有别于过量底物的结合部位。     

提取酶法测定FDP

本文建立了提取酶法测定１,６－二磷酸果糖的方法,该法检测发酵生产过程中所生成的１,６－二磷酸果糖的含量准确度高,检测迅速、可靠。     

光／暗对玉米叶片果糖—6—磷酸激酶—2和果糖—2,6—二磷酸酯酶活…

比较了照光和黑暗条件下玉米叶片果糖－６－磷酶激酶－２和果糖－２,６－二磷酸酯酶的活力变化。当玉米植株从暗中转入光下后,其叶片ＰＦＫ－２的活力随光照时间的延长而逐渐降低,而ＦＢＰａｓｅ－２活力变化不明显;从光下转入暗后叶片ＰＦＫ－２活力明显上升,ＦＢＰａｓｅ－２活力仍无明显变化;其ＰＦＫ－２／ＦＢＰａｓｅ－２比值在光处理时下降,暗处理时上升。同时叶片中果糖－２,６－二磷酸的含量与ＰＦＫ－２／ＦＢＰａ     

BA对花生叶片蔗糖和淀粉代谢有关酶活性的影响

用１０－５ｍｏｌ／ＬＢＡ处理去顶去根花生幼苗库叶２４ｈ内．蔗糖磷酸合成酶和细胞质果糖－１,６－二磷酸酯酶活性逐渐增加．酸性转化酶活性降低．使蔗糖含量提高,α－淀粉酶活性的增强,促进淀粉分解。ＢＡ处理２４ｈ后,随着蔗糖磷酸合成酶和细胞质果糖－１．６－二磷酸酯酶活性的减弱．酸性转化酶活性逐渐增加．蔗糖含量减少,有利光合碳在淀粉的积累．     

畲族Gc、PGM1、AcP_1、6-ΡGD、ADA和AK1的遗传多态性

对畲族血浆组特异性成分（Ｇｃ）、红细胞磷酸葡萄糖变位酶１（ＰＧＭ１）、酸性磷酸酶（ＡｃＰ１）、６－磷酸葡萄糖酸脱氢酶（６－ＰＧＤ）、腺苷脱氨酶（ＡＤＡ）、腺苷酸激酶（ＡＫ１）的遗传多态性进行了研究。Ｇｃ与ＰＧＭ１是用薄层聚丙烯酰胺凝胶等电聚焦分析的,ＡｃＰ１、６－ＰＧＤ、ＡＤＡ及ＡＫ１是用淀粉凝胶电泳分析的。各基因座的基因频率分别为Ｇｃ＊１Ｆ０．４７２２、Ｇｃ＊１Ｓ０．２４２１、Ｇｃ＊２０．２７３８;ＰＧＭ１＊１Ａ０．５３５７、ＰＧＭ１＊１Ｂ０．１６２７、ＰＧＭ１＊２Ａ０．１５８７、ＰＧＭ１＊２Ｂ０．１４２９;ＡｃＰ＊１Ａ０．１８２５、ＡｃＰ１＊Ｂ０．８１７５;６－ＰＧＤ＊Ａ０．９６８３、６－ＰＧＤ＊Ｂ０．０２７８;ＡＤＡ＊１０．９８８１、ＡＤＡ＊２０．０１１９;ＡＫ１＊１１．００００。畲族Ｇｃ、ＰＧＭ１、ＡｃＰ１、６－ＰＧＤ和ＡＤＡ基因为多态,而ＡＫ１基因为单态。发现１例带有６－ＰＧＤ＊Ｒ和３例带有Ｇｃ＊１Ａ２变异等位基因的个体,其中Ｇｃ＊１Ａ２基因频率为０．０１１９,达到多态水平。     

感染流行性出血热病毒的正常人骨髓细胞膜脂和酶生物活性的研究

采用疏水性荧光探针ＤＰＨ（１,６,－苯基－１,３;５－已三烯）标记感染了流行性出血热病毒的正常人骨髓细胞的细胞膜,根据荧光偏振值的变化推导出膜脂流动性,同时通过细胞组化染色定量方法,测定细胞内酸性磷酸酶（ＡＣＰ）和琥珀酸脱氢酶（ＳＤＨ）的活性。动态观察１、６、２４、７２ｈ培养后的淋巴细胞、单核细胞、中性粒细胞,发现感染后细胞膜脂的流动性明显降低,并随培养时间的延长而明显,和正常对照组比较有显著性差异（Ｐ＜０．０５～０．０１）。通过组化染色和显微分光光度计单细胞扫描定量认为：感染细胞在培养开始的７２ｈ内ＡＣＰ、ＳＤＨ升高,１２０ｈ后明显下降,和正常相比亦有显著差异（Ｐ＜０．０５）,这与病毒侵犯和细胞机能的受损程度有关。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.