共查询到20条相似文献，搜索用时 15 毫秒
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A moderate light stimulus induced isoelectric point (pI) changes in three classes of retina-specific polypeptides (80, 49, and 39 kilodaltons) of Drosophila in vivo. When inorganic phosphate labeled with phosphorus-32 was fed to flies, the radioactive label was incorporated into these polypeptides during the pI changes, indicating light-induced phosphorylation of the polypeptides. A 1-millisecond flash induced a detectable amount of phosphorylation in the 80- and 49-kilodalton polypeptides within 3 seconds. These results, and our previous results with norpA mutants, suggest that phosphorylation of these two polypeptides may be involved in some early stages of photoreceptor excitation or its modulation. 相似文献
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土壤干旱对小麦根系蛋白组分变化的影响 总被引：11，自引：0，他引：11
在土壤干旱条件下,小麦幼苗根系组织含水量降低,可溶蛋白质含量增加.SDS—PAGE扫描图谱表明,陕合6号出现46、59及60KD3种新蛋白质峰值,郑引1号产生24、46、61、63、65、69、及72KD7种新蛋白质峰值.两个品种在15～72KD间的多数蛋白质含量显著增加,而15KD以下的蛋白质含量大幅度下降.复水后,新蛋白质消失,15KD以下的蛋白质含量接近对照水平,而15～72KD间的蛋白质含量明显低于对照. 相似文献
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从林蛙皮肤中提取的小分子多肽具有诸多生物活性。以鲜活林蛙为试验材料,剥离皮肤,采用酶解法提取小分子活性多肽,并研究其理化性质。结果表明:制备的林蛙皮多肽的紫外特征吸收峰位于220 nm处,280 nm附近吸收峰较小;分子量主要分布在190~1 000 u,并且在250~540 u的分布最多,占37.47%;该混合多肽具有多种生物活性因子,尤其是抗菌肽和凋亡调控蛋白;在不同p H值缓冲溶液中都具有良好的溶解性;抑菌试验表明其对大肠杆菌和金黄色葡萄球菌有不同程度的抑菌活性。证明制备的小分子混合多肽有望成为新的制剂原料。 相似文献
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李国勋 《东北农业大学学报》1990,(1)
本文采用限制性内切酶,分析木薯天蛾颗粒体病毒(Erinnyis ello Granulosis Virus简称EeGV)的DNA。同时,利用聚丙烯酰胺凝胶电泳(SDS—PAGE),对病毒包涵体蛋白质和病毒粒子结构多肽进行分析。结果表明,EeGV基因组的分子量为89.82 Kbp(硷基对);包涵体蛋白只有一条带,其分子量为31.0KDa(道尔顿);病毒粒子至少有18种结构多肽,其分子量在14.00～205.00 KDa范围之间,其中,有6条带明显地不同于Piris rapae GV和Trichoplusia ni GV;经EcoR_1,Hind Ⅲ,Kpnl酶解的EeGV DNA片段数目和分子量都明显不同于PrGV和TnGV的DNA片段。 相似文献
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Hypothalamic regulatory hormones 总被引：13，自引：0，他引：13
The molecular structures of several polypeptides isolated from hypothalamic tissue have been established and the synthesis of these compounds has been achieved. These polypeptides selectively stimulate or inhibit the release of anterior pituitary hormones and melanocyte-stimulating hormone. Various studies indicate their important physiological role and support the concept that some of these polypeptides are hormones. Some synthetic hypothalamic hormones and their derivatives may find important clinical and veterinary applications. 相似文献
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Analysis of the subunit polypeptide composition of Fraction 1 proteins gives information on the expression of both nuclear and chloroplast genomes; the large subunits of the protein are coded by chloroplast DNA, whereas the small subunits are coded by nuclear DNA. Fraction 1 protein isolated from the leaves of parasexual hybrid plants derived from the fusion of protoplasts of Nicotiana glauca and N. langsdorffii contains the small subunit polypeptides of both parent species and the large subunit polypeptides of only N. glauca. Fraction 1 protein isolated from the leaves of a hybrid plant obtained after the uptake of chloroplasts of N. suaveolens by protoplasts of white tissue of a variegating mutant of N. tabacum contains the large subunit polypeptides of both N. suaveolens and N. tabacum, as well as the small subunit polypeptides of both these species. 相似文献
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大竹蛏源多肽与钙螯合物的制备工艺及生物活性研究 总被引：1，自引：0，他引：1
以大竹蛏肉蛋白和氯化钙为原料,复合酶解法制备大竹蛏源多肽螯合钙,考察螯合温度、时间、大竹蛏源多肽与钙离子的质量比和pH对螯合率和螯合物中钙含量的影响。根据响应面分析试验结果,在温度50℃,时间40 min,质量比1∶2,pH7.0条件下,螯合率为32.73%,螯合物中钙含量为41.89%。傅里叶变换红外光谱扫描检测结果表明,竹蛏源多肽与钙离子形成了螯合物,以硫代巴比妥酸法和抑菌圈试验分别验证此螯合物具有抗氧化活性和抑菌活性。 相似文献
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为进一步探讨豌豆光系统I(PSⅠ)的结构与多肽组成,本研究提取了经DOC-PAGE分离的光系统I多肽,采用毛细管凝胶电泳方法,以1%的葡聚糖为毛细管凝胶线性高分子筛分基质,0.5%乙基纤维素,0.1%SDS为磷酸盐缓冲液添加剂。在35min内进行了较好地分离。所得的色谱图基线平稳、分离度较高。为进一步利用毛细管电泳技术进行蛋白复合物多肽的分离奠定了良好的基础。 相似文献
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Protein sequence analysis: automated microsequencing 总被引：15，自引：0，他引：15
The automated microsequencing of proteins can now be carried out at the 5- to 10-picomoles (submicrogram) level on polypeptides obtained directly from one- and two-dimensional gel electrophoresis. The techniques are applicable to polypeptides ranging in size from small peptides (less than 10 residues) to large proteins (more than 1000 residues). 相似文献
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Kaiser CM Goldman DH Chodera JD Tinoco I Bustamante C 《Science (New York, N.Y.)》2011,334(6063):1723-1727
Proteins are synthesized by the ribosome and generally must fold to become functionally active. Although it is commonly assumed that the ribosome affects the folding process, this idea has been extremely difficult to demonstrate. We have developed an experimental system to investigate the folding of single ribosome-bound stalled nascent polypeptides with optical tweezers. In T4 lysozyme, synthesized in a reconstituted in vitro translation system, the ribosome slows the formation of stable tertiary interactions and the attainment of the native state relative to the free protein. Incomplete T4 lysozyme polypeptides misfold and aggregate when free in solution, but they remain folding-competent near the ribosomal surface. Altogether, our results suggest that the ribosome not only decodes the genetic information and synthesizes polypeptides, but also promotes efficient de novo attainment of the native state. 相似文献
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余龙喜 《湖南农业大学学报(自然科学版)》1989,(4)
本文就山靛雄性不育系、雄性恢复系、雄性可育系以及雌性系生殖器官poly(A)~+RNA进行了蛋白质体外翻译,并对其翻译产物进行了单向和双向电泳的分析。结果表明.各系均具有独特的多肽和不同的基因表达方式,为深入开展高等植物雄性不育及性别分化的分子遗传学研究提供了依据。 相似文献
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对红褐林蚁的多肽蛋白质进行了分离和制备,并对其免疫活性、镇痛及抗感染作用进行了研究.红褐林蚁水提物经SephadexG-50凝胶过滤层析分离得到组分Ⅰ和组分Ⅱ,经紫外检测均为蛋白质;每个组分经反相高效液相色谱分离和制备,组分Ⅰ得到a,b,c3个组分,其中组分a含量最高;组分Ⅱ得到d,e,f3个组分,其中组分e含量最高.淋巴细胞转化试验结果显示：组分a和组分e能抑制淋巴细胞增殖,表明其具有免疫活性;热板法所致小鼠痛阈值的变化和二甲苯诱发小鼠耳肿胀试验显示：红褐林蚁多肽试剂具有镇痛和抗感染作用. 相似文献
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The hydroxyproline and hydroxylysine in collagen are synthesized by an apparently unique pathway in which proline and lysine are hydroxylated after they are incorporated into a large polypeptide precursor of collagen called protocollagen. When the hydroxylation of protocollagen in isolated tissues is intermittently interrupted, hydroxylation can occur after complete polypeptides are released from ribosomal complexes. Cartilage from chick embryos was incubated with the iron chelator alpha,alpha'-dipyridyl for 2 hours to inhibit protocollagen hydroxylase, and then the inhibition was reversed by transferring the tissues to medium containing ferrous iron and no alpha,alpha'-dipyridyl. "Pulse labeling" of the tissues during these two periods indicated that both the accumulated protocollagen and the polypeptides synthesized after reversal of the inhibition were hydroxylated at the same rate. Even when no measures are taken to inhibit the hydroxylation of protocollagen, most of the hydroxyproline in collagen is probably synthesized after complete protocollagen polypeptides are released from ribosomes. 相似文献
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猪血浆酶解肽的制备工艺及免疫调节功能的初步研究 总被引：1，自引：0，他引：1
采用酶解和活性炭相结合的方法对猪血浆的脱色条件进行优化,并对脱色酶解物喷雾干燥后得到的产品功能进行初步动物试验评价。结果表明:采用酶解与活性炭相结合的方法对猪血浆进行脱色,脱色率达90.60%,同时还可以将血浆蛋白分解成多肽,且此多肽对兔的细胞因子(IL-1β、IL-6、IFN-γ、INF-α)的调节起着良好的作用。 相似文献
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The misincorporation of isoleucine provoked by streptomycin in a polyuridylate-directed incorporating system from Escherichia coli has been examined by a double-labeling technique with phenylalanine-(3)H and isoleucine-(14)C. The polypeptides synthesized are associated with 70S ribosomes and contain only phenylalanine in the absence of streptomycin, and both phenylalanine and isoleucine in the presence of the antibiotic. Results of acid hydrolysis and subsequent chymotryptic digestion of the polypeptides indicate that the misincorporated amino acid is inserted by peptide bonding with phenylalanine and is randomly distributed along the chain. 相似文献
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以亲和层析法提纯的猪瘟兔化毒用2%的Tritonx-100裂解后,经SDS-PAGE法分析,表明它有3种结构多肽,即：GP#-1（54-58KD）,GP#-2（24.5-28KD）,CP（7-10KD）。GP#-2在凝胶中稍有扩散,出现较长的拖尾现象。经PAS（Periodic Acid Schiffis reagent）染色证明,GP#-1、GP#-2为糖蛋白,用免疫印迹法测知：GP#-2能与猪瘟抗体结合,而GP#-1,CP则不能结合。3种蛋白成份的氨基酸组成及含量有一定差异。CP与GP#-1、GP#-2之间的差别较大。GP#-1、GP#-2可能是病毒的囊膜蛋白成份,CP可能是衣壳的蛋白成份。 相似文献
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A 115-kD polypeptide immunologically related to erythrocyte band 3 is present in Golgi membranes 总被引：5，自引：0，他引：5
S Kellokumpu L Neff S J?ms?-Kellokumpu R Kopito R Baron 《Science (New York, N.Y.)》1988,242(4883):1308-1311
Band 3 multigene family consists of several distinct but structurally related polypeptides which are probably involved in the transport of anions across the plasma membrane of both erythrocytes and nonerythroid cells. A novel member of this family of polypeptides that resides in the Golgi complex was identified with antibodies to Band 3. The Golgi antigen had a larger molecular size and was antigenically distinct from Band 3 in the amino-terminal domain. It was expressed most prominently in cells that secrete large amounts of sulfated proteins and proteoglycans. This polypeptide may participate in sulfate transport across Golgi membranes. 相似文献
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本文报道不连续系统的 SDS-PAGE 法对甘蓝夜蛾核型多角体病毒(Mamestrabrassicae nuclear polyhedrosis virus MbNPV)的多角体蛋白,病毒粒子结构多肽进行分析。结果表明,经热处理和温和碱解的多角体蛋白呈现一条带,分子量为28.2×10~3±500道尔顿。病毒粒子至少有15种多肽.MbNPV 多角体蛋白富含天门冬氨酸、谷氨酸。未检出色氨酸、限制性内切酶 ECoR Ⅰ,HindⅢ,BamH Ⅰ和 Pst Ⅰ分别把 MbNPV-DNA 酶解成15,13,7和10个限制性片段.由片段积加法计算得平均分子量为95.905±2.164Kbp. 相似文献