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1.
Demonstration that a chemically synthesized BPV1 oncoprotein and its C-terminal domain function to induce cellular DNA synthesis 总被引:17,自引:0,他引:17
Bovine papillomavirus type 1 contains the smallest known oncogene (ORF E5), encoding a hydrophobic 44 amino acid protein. To study the biochemical functions of the E5 oncoprotein, we have chemically synthesized it and several deletion mutant peptides. We demonstrate induction of cellular DNA synthesis in growth-arrested cells by microinjection of E5 oncoprotein. This activity can be broken down into two functionally distinguishable domains. Remarkably, the first domain, which alone is sufficient to induce cellular DNA synthesis, contains only the C-terminal 13 amino acids. This is the smallest known protein fragment that can autonomously activate cellular DNA synthesis. The second domain is the hydrophobic middle region, which by itself fails to induce cellular DNA synthesis but confers a 1000-fold increase in specific activity. The N-terminal one-third of the molecule is dispensable for induction of DNA synthesis. 相似文献
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HIF-1 expression in healing wounds: HIF-1alpha induction in primary inflammatory cells by TNF-alpha 总被引:12,自引:0,他引:12
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Maria V. Sergeeva Vadim V. Mozhaev Joseph O. Rich Yuri L. Khmelnitsky 《Biotechnology letters》2000,22(17):1419-1422
A novel biocatalytic reaction of transamidation of non-activated amides with amines is reported. Among 45 different lipolytic and proteolytic enzymes tested, only the lipase from Candida antarcticawas able to catalyze this reaction. The reaction proceeded with up to ca. 80% conversion in anhydrous methyl tert-butyl ether and worked with both N-substituted and unsubstituted amides. The biocatalytic transamidation is an equilibrium process and, therefore, higher conversions to the desired amide were achieved by using increased concentrations of the amine nucleophile. 相似文献
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A Monte Carlo simulation of clone growth is discussed from the point of view of clonal volume. It is shown that clone volume is a good representation of the number of cells per clone for a wide range of single cell growth equations. However, the rate at which the coefficient of variation in clonal volume approaches that of cell number per clone is strongly dependent upon the particular growth equation. 相似文献
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A method is described for the subcellular fractionation of goldfish xanthophores. The procedure produces relatively pure fractions of caroteniod droplets, pterinosomes, cytosol and what appears to be plasma membrane. The presence of a distinct pattern of proteins is shown to be associated with the carotenoid droplets. Treatment of the xanthophores with ACTH affects the buoyant density of some carotenoid droplets and stimulates the phosphorylation of a polypeptide associated with the carotenoid droplets. 相似文献
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