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蛋白酶抑制剂及其在抗虫基因工程中的应用 总被引:41,自引:0,他引:41
蛋白酶抑制剂可以抑制昆虫的生长和发育,近年来在抗虫基因工程得广泛的应用。本文综述了蛋白酶抑制剂及其抗虫性,蛋白酶抑制剂转基因植物的研究概况,同时探讨了蛋白酶抑制剂在抗虫基因工程中的利用前景、存在问题和解决途径。 相似文献
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植物蛋白酶抑制剂在植物抗虫与抗病中的作用 总被引:13,自引:0,他引:13
综述了植物蛋白酶抑制剂抗虫与抗病作用的研究进展.蛋白酶抑制剂广泛存在于植物体内,与植物抗虫抗病密切相关.植物蛋白酶抑制剂能抑制昆虫肠道蛋白酶,使昆虫生长发育缓慢,甚至死亡.但取食蛋白酶抑制剂后,昆虫能迅速分泌对抑制剂不敏感的蛋白酶,而使蛋白酶抑制剂无效.食物蛋白的含量和质量也影响植物蛋白酶抑制剂的抗虫效果.病原菌的感染能诱导植物产生蛋白酶抑制剂,诱导产生的蛋白酶抑制剂能抑制病原菌的生长. 相似文献
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HIV-2蛋白酶已成为治疗艾滋病的一个重要药物靶标。作者采用分子动力学模拟并结合自由能计算,研究了抑制剂Amprenavir(AMP)与HIV-2蛋白酶的作用机制。研究结果表明范德华作用是AMP与HIV-2蛋白酶结合的主要力量。采用基于残基的自由能分解方法计算抑制剂-残基相互作用,结果表明疏水性的CH-π和CH-O相互作用驱动了抑制剂AMP与HIV-2蛋白酶的结合。作者期望这一研究结果能为抗艾滋病双重抑制剂的研发提供一定的理论指导。 相似文献
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Kunitz型丝氨酸蛋白酶抑制剂是一类普遍存在的蛋白酶抑制剂,在体内各项生命活动中扮演着重要角色。这类抑制剂结构稳定且富有特色,通常具有一个或几个串联存在的Kunitz结构域,能够以类似底物的方式与丝氨酸蛋白酶结合,从而抑制酶的活性。在功能方面,Kunitz型丝氨酸蛋白酶抑制剂参与凝血和纤维蛋白溶解、肿瘤免疫、炎症调节以及抵抗细菌、真菌感染等过程。文中就Kunitz型丝氨酸蛋白酶抑制剂研究进展作一综述,为新型Kunitz型丝氨酸蛋白酶抑制剂的开发提供研究思路。 相似文献
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丝氨酸蛋白酶抑制剂的结构与功能 总被引:3,自引:1,他引:2
戚正武 《生物化学与生物物理进展》1988,15(5):322-329
本文介绍了三种丝氨酸蛋白酶抑制剂。绿豆胰蛋白酶抑制剂与慈菇蛋白酶抑制剂均为双头抑制剂,分别由72与141个氨基酸残基所组成。绿豆抑制剂能被胃蛋白酶降解为活性中心分别为Lys及Arg的两个活性碎片,其抑制剂本身及Lys碎片的晶体结构已阐明。慈菇抑制剂有A、B两个主要组份,两者对不同蛋白酶有不同抑制活性,是一种新类型的抑制剂。天花粉胰蛋白酶抑制剂是迄今已知的最小多肽抑制剂,共含27个氨基酸残基,用2D-NMR研究了它的构象。讨论了上述三种抑制剂的异同。 相似文献
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经硫酸铵分级、CM-纤维素柱层析和Sephadex G-75柱层析,从野生型秘鲁蕃茄未成熟果实的匀浆液中分离纯化了蛋白酶抑制剂Ⅱa、Ⅱb。纯化的蛋白酶抑制剂经SDS-PAGE鉴定呈单一带,分子量均为17kD。Western blotting结果表明蛋白酶抑制剂Ⅱa、Ⅱb均与马铃薯蛋白酶抑制剂Ⅱ有血清学上的交叉反应。抑制蛋白酶活性测定显示两种蛋白酶抑制剂都表现強的抑制胰凝乳蛋白酶的活性,但对胰蛋白酶的抑制活性蛋白酶抑制剂Ⅱb強于蛋白酶抑制剂Ⅱa。 相似文献
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果实膨大期喷布磷酸二氢钾对三月红荔枝果实贮藏性的影响 总被引:1,自引:0,他引:1
在三月红荔枝(Litchi chinensis cv.Sanyuehong)果实膨大期对树冠喷施0.2%磷酸二氢钾(KP)水溶液,以探讨磷酸二氢钾对荔枝果实贮藏性的影响。结果表明:(1) KP处理的果实在贮藏期前17d,失重率及果肉可溶性固形物、酸、VitC、花色素苷等指标的变化趋势与对照基本相似;(2) KP处理的果肉可溶性蛋白质含量变化与对照有明显差异,而果皮的可溶性蛋白质含量在贮藏期前10d变化动态与对照一致,此后呈相反的变化趋势;(3)果皮POD活性显著高于果肉,KP处理和对照的果肉POD活性在贮藏第3d后、果皮POD活性在第17d前分别具有相似变化趋势;(4)果肉中CAT活性在贮藏第3~17d期间都显著或极显著高于果皮,KP处理和对照果肉、果皮CAT活性动态变化均为单峰曲线。 相似文献
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The titre of apple chlorotic leaf spot virus (ACLSV) was higher in microplants of Malus domestica cv. Jonagold than in 2-year-old grafted scions. Cytokinin concentration in the medium increased the titre of prunus necrotic ringspot virus (PNRSV) in the apex of microplants of Prunus insititia cv. Kozlienka but did not affect the titre of ACLSV in M .domestica.Virus titre of ACLSVwas higher in the haulms of autotrophically-grown compared with heterotrophically-grown microplants whereas as for PNRSV the results were the reverse. For both viruses, however, titre of the virus in the roots of autotrophically-grown plants was significantly higher than in haulm tissue from heterotrophic cultures. Ribavirin incorporation resulted in elimination of both viruses. Negative ELISA results were confirmed independently by PCR. The efficacy of Ribavirin in elimination of ACLSV was increased by increasing the concentration of cytokinin in the medium in parallel with decreasing the concentration of Ribavirin. These results are discussed in the context of the reliability of in vitro virus testing. 相似文献
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Balijepalli S Tirumalai PS Swamy KV Boyd MR Mieyal JJ Ravindranath V 《Journal of neurochemistry》1999,72(3):1170-1178
Thioltransferase (TTase) is a member of the family of thiol-disulfide oxidoreductases that are involved in the maintenance of sulfhydryl homeostasis in cells by catalyzing thiol-disulfide interchange reactions. One of the major consequences of oxidative stress in brain is the formation of protein-glutathione mixed disulfides (through oxidation of protein thiols), which can be reversed by TTase during the recovery of brain from oxidative stress. We therefore examined the presence of TTase in brain regions from rat. In the rat, TTase activity in the whole brain was comparable with the corresponding activity in liver, but significantly higher in hippocampus. The enzyme activity was significantly lower in striatum and cerebellum compared with activity in whole brain. Rat brain TTase shared immunological similarity with the human red blood cell enzyme, but not with the pig liver enzyme. The constitutive expression of the mRNA to TTase was demonstrable by northern blotting. Localization of the TTase mRNA in rat brain by fluorescent in situ hybridization showed the presence of high amounts of mRNA in the olfactory bulb, cortex, and hippocampus and its predominant localization in the neurons. TTase mRNA was also present in Purkinje cells in the cerebellum, in giant reticular neurons in the midbrain, and in the striatal and thalamic neurons. This study demonstrates the constitutive presence of a functional TTase system in brain and delineates the regional and cellular localization of the enzyme in rat brain. 相似文献
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According to data of observations in 2002–2004, differences in the pattern of diurnal fluctuations in the total content and fractional composition of lipids in muscles of mature specimens of kilka Clupeonella cultriventris from the Rybinsk Reservoir in the feeding and spawning periods were revealed. It was established that the feeding intensity in kilka considerably changes throughout 24 h in both periods of the annual cycle, while diurnal fluctuations in the fatness of muscles are distinctly manifested only in the reproductive period and have a dissimilar pattern in specimens of different sexes. In females and males, they are determined mainly by the change in the content of the fraction of reserve lipids-triacylglycerols, as a rule, by its increase in the light hours of the day, several hours after an increase in the feeding activity of fish. The pattern of diurnal fluctuations of the level of lipid fractions (phospholipids, triacylglycerols, cholesterol, and its ethers) in kilka’s muscles differs from that in the feeding period. Possible causes of the change of diurnal variations of the considered indices of lipid metabolism in kilka at an increase in the endocrine activity of its body in the reproductive period is discussed. 相似文献
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The population dynamics of Moniliformis moniliformis was studied in ‘free-ranging’ laboratory rats, Rattus norvegicus, presented with different relative density levels of M. moniliformis in cockroaches, Periplaneta americana. Changes in selected population parameters of the negative binomial distribution were evaluated as indicators of changes in aggregation. A significant increase in the degree of aggregation of parasites occurred as a result of the increase in relative density of infective stages available to the rats. This increase in aggregation was due to the increase in over-dispersion that occurred in female rats only. The degree of aggregation in females was found to be significantly higher than that in males at both treatment levels. The best indicators of the degree of aggregation were found to be the ratio of the variance to the relative density and the ratio of the log-variance to log-relative density. Changes in k were not correlated with changes in over-dispersion or the relative density. 相似文献
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We assessed the distribution and abundance of 4 species of diurnal primates viz. lion-tailed macaque, bonnet macaque, Nilgiri langur and Hanuman langur, in 2 areas—Brahmagiri-Makut and Sirsi-Honnavara—in rain forests of the Western Ghats in the state of Karnataka, India. The Nilgiri langurs in Brahmagiri-Makut and the lion-tailed macaques in Sirsi-Honnavara are the northernmost populations of the 2 species in the Western Ghats. The 2 regions represent changes in ecological zones in the Western Ghats. In Brahmagiri-Makut, Hanuman langurs and bonnet macaques occupy lower elevations whereas Nilgiri langurs live in relatively higher altitudes. Only one group of lion-tailed macaques was in Brahmagiri-Makut. In the forests of Sirsi-Honnavara, 3 species of primates viz. lion-tailed macaque, bonnet macaque and Hanuman langur were in larger numbers throughout the forest. A self-sustainable single population of 32 groups of lion-tailed macaques occurred in Sirsi-Honnavara. Few subspecies of Hanuman langurs exist in the study regions. Due to local hunting practices, the relative abundance of primates in Brahmagiri-Makut is lower than that in Sirsi-Honnavara. 相似文献
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The microsporogenesis in Pinus thunbergii occurs in early to middle March, and the development of pollen in late March to early April. A mature pollen grain consists of four cells. The starch grains aggregate in the equators during meiosis Ⅰ to Ⅱ. The callose materials appear first in inner side of the wall of meiocyte and then in the equator. Sometimes the 3-or 4-sac- cate pollen grains have been found. In the ontogeny of pollen in Pinus thunbergii following events are noteworthy. (1) During meiosis the equatorial aggregation of starch grains in me iocyte becomes conspicuous. (2) During formation of tetrad the callose wall appears in regular activity. It is noteworthy that there is itself feature for the accumulation of callose in Pinus thunbergii. After formation of prothallial cells the callose appears mainly in the area between body and saccus. So the prominent symmetry of distribution of callose occurs in the pollen grains. But almost no callose accumulation takes place i,n tenuity in distal face of pollen grain. On the contrary, there are certain callose accumulation around the prothallial cells in the proximal face, forming the polar distribution of callose in pollen grains. 相似文献
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T. Kotok R. L. Bogorad A. N. Smirnov V. M. Turovetskii O. V. Smirnova 《Russian Journal of Developmental Biology》2000,31(2):117-123
Using the technique of immunohistochemistry in combination with cytophotometry, we have studied the effect of periovulatory
hyper- and hypoprolactinemia on the expression of prolactin receptors in various cell types of rat ovaries during early estrus.
It has been shown that intense specific staining of oocytes is positively controlled by prolactin. The maximal intensity of
specific staining was found in cells of the cumulus and the inner layer of granulosa cells in mature follicles; staining intensity
gradually diminished towards the outer boundary cell layer. Postovulatory follicles are distinct from those mature follicles
in which there was no ovulation in their more intense manifestation of prolactin receptors in cells of the inner layer and
cumulus, as well as in increased positive staining (after prolactin administration) only in the granulosa layer cells closest
to theca. In follicles which did not ovulate by the time of the early estrus, prolactin administration leads to a proportional
growth of specific immunoreactivity in all cell layers of the granulosa. The administration of bromocryptin, an inhibitor
of prolactin secretion, leading to a 10-fold decrease in the prolactin level in the blood, results in a twofold decrease in
the intensity of specific staining of all cell layers of the granulosa in either type of follicle. Corpora lutea of the previous
cycle have irregularly positioned luteocytes with weak and strong specific staining, the intensity of which is not changed
in response to prolactin and diminishes slightly after the administration of bromocryptin. We conclude that the most intense
changes in the content of prolactin receptors under the conditions of imbalance of this hormone during the periovulatory period
are observed in those follicles where the oocyte did not ovulate by the time of early estrus. 相似文献
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Unniappan S Peter RE 《Comparative biochemistry and physiology. Part A, Molecular & integrative physiology》2005,140(4):396-408
Ghrelin was originally purified and characterized in rats and humans as the first identified endogenous ligand of the growth hormone secretagogue receptor. In mammals, ghrelin is mainly produced in the stomach, with minor levels of ghrelin present in the brain and various other tissues. Ghrelin is involved in the regulation of many physiological functions including the regulation of growth hormone secretion and food intake in mammals. The gene and peptide structures of ghrelin have been recently identified in several fish species. As in mammals, ghrelin mRNA is mainly expressed in the gut of fish. Ghrelin is involved in the regulation of a number of physiological functions, including the regulation of pituitary hormone release and the stimulation of food intake in fish. In this review, we wish to provide an up-to-date discussion on the structure, distribution and functions of ghrelin in fish, in comparison to ghrelin in other vertebrates. 相似文献
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Kensuke Miyamoto Yuko Mitani Kouichi Soga Junichi Ueda Kazuyuki Wakabayashi Takayuki Hoson Seiichiro Kamisaka Yoshio Masuda 《Physiologia plantarum》1997,101(1):38-44
When white light irradiation inhibits shoot growth in derooted pea ( Pisum sativum L. cv. Alaska) cuttings, it decreases tissue tension, a driving force for shoot growth, by making the cell wall of the inner tissues mechanically rigid. To elucidate the mechanism by which light affects the mechanical properties of the cell wall in the inner tissues, its effect on the chemical properties of the cell walls was studied by analyzing qualitatively and quantitatively cell wall polysaccharides in the epdidermis and inner tissue of pea epicotyls grown in both dark and light. The amount of polysaccharides per subhook in the cell walls of both tissues increased during a 4-h dark incubation. Light suppressed the increase in hemicellulosic (HC)-II and cellulosic polysaccharides in the inner tissues, while it did not affect the increase in other wall fractions in either the epidermal or subepidermal tissues. No light effect was observed on the neutral sugar compositions of pectin, HC-I or HC-II fractions in either of the tissues. Light increased the mass-average molecular mass of xyloglucan and rhamnoarabinogalactan in HC-II fractions in the inner tissues, while such an effect was not observed in the epidermis. These facts suggest that the light-induced decrease in the tissue tension in pea epicotyls is caused by an increase in the molecular size of xyloglucan, rhamnoarabinogalactan in the HC-II fraction and/or the suppression of the synthesis of HC-II and cellulosic polysaccharides in the inner tissues. 相似文献