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《Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology》1991,1076(1):97-102
Cyanide binding to Chromatium vinosum ferricytochrome c′ has been studied to further investigate possible allosteric interactions between the subunits of this dimeric protein. Cyanide binding to C. vinosum cytochrome c′ appears to be cooperative. However, the cyanide binding reaction is unusual in that the overall affinity of cyanide increases as the concentration of cytochrome c′ decreases and that cyanide binding causes the ligated dimer to dissociate to monomers as shown by gel-filtration chromatography. Therefore, the cyanide binding properties of C. vinosum ferricytochrome c′ are complicated by a cyanide-linked dimer to monomer dissociation equilibrium of the complexed protein. The dimer to monomer dissociation constant is 20-fold smaller than that for CO linked dissociation constant of ferrocytochrome c′. Furthermore, the pH dependence of both the intrinsic equilibrium binding constant and the dimer to monomer equilibrium dissociation constant was investigated over the pH range of 7.0 to 9.2 to examine the effect of any ionizable groups. The equilibrium constants did not exhibit a significant pH dependence over this pH range. 相似文献
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Helmut Bäumlein James Pustell Ulrich Wobus Steven T. Case Fotis C. Kafatos 《Journal of molecular evolution》1986,24(1-2):72-82
Summary The 3-end sequences of two nonallelic genes derived from the Balbiani ring c (BRc) locus ofChironomus thummi are described. Only one of the genes appears to be transcribed abundantly in normal late larval salivary glands. The two sequences are highly similar, even in the 3 untranslated regions, but sharply diverge beyond the polyadenylation site. Together with evidence from the 3 ends of BR1 and BR2 genes ofC. pallidivittatus andC. tentans, independently characterized by others, this result suggests the existence of a sequence-homogenization mechanism that operates across the 3 ends of all BR genes characterized to date. The 3-terminal coding region of each BRc gene is divided into two portions by a short intron. The upstream portion is homologous to and continuous with the tandem repeats that make up the internal core of each BR gene; however, that portion is variant in sequence relative to the core, and apparently is not subject to the homogenization process that operates on the core repeats. The portion downstream of the intron encodes a unique, 111-residue polypeptide highly different from the rest of the BRc product. The evolution of the various segments of the BRc genes is discussed. 相似文献
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Marc M. Greenberg Dong Jin Yoo Brian K. Goodman 《Nucleosides, nucleotides & nucleic acids》2013,32(1-2):33-40
Abstract ABSTRACT C1′ acylated derivatives of 2′-dcoxyuiidinc (1a-c) were synthesised from 1-[3-deoxy-β-D-psieofiiraiiosylliii.acil (6). The acyl group is introduced via the C1′ aldehyde (11). Following nucleophilic addition, the ketones (1a-c) are obtained via periodinane oxidation and desilylation with NH4F. 相似文献
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G. M. Visser R. Keemink Cecile Schattenkerk B. Kraal J. H. Van Boom 《Nucleosides, nucleotides & nucleic acids》2013,32(3):277-286
Abstract Phosphorylation of 2′-0-acetyl-3′-trifluoroacetamido-3′-deoxy-N2-palmitoylguanosine with N-morpholino-O, O-bis(1-benzotriazolyl)phos-phate gives a 5′-phosphotriester. Removal of the benzotriazolyl group and addition of pyrophosphoric acid gave, after deblocking all protecting groups, GTP(3′NH2). 相似文献
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Anilkumar R. Kore Bo Yang Balasubramanian Srinivasan Annamalai Senthilvelan 《Nucleosides, nucleotides & nucleic acids》2015,34(1):33-39
We describe concise and efficient synthesis of biologically very important 3′-O-tetraphosphates namely 2′-deoxyadenosine-3′-O-tetraphosphate (2′-d-3′-A4P) and 2′-deoxycytidine-3′-O-tetra-phosphate (2′-d-3′-C4P). N6-benzoyl-5′-O-levulinoyl-2′-deoxyadenosine was converted into N6-benzoyl-5′-O-levulinoyl-2′-deoxyadenosine-3′-O-tetraphosphate in 87% yield using a one-pot synthetic methodology. One-step concurrent deprotection of N6-benzoyl and 5′-O-levulinoyl groups using concentrated aqueous ammonia resulted 2′-d-3′-A4P in 74% yield. The same synthetic strategy was successfully employed to convert N4-benzoyl-5′-O-levulinoyl-2′-deoxycytidine into 2′-d-3′-C4P in 68% yield. 相似文献
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Differences between α- and β-lipovitellin were examined, especially in regard to the polypeptide and carbohydrate composition of apolipoprotein. Both lipoproteins were composed of at least eight polypeptides with similar molecular weights ranging from 35,000 to 140,000 daltons. Polypeptides with 110,000 daltons were common major constituents. The close similarity of component polypeptides in the two lipoproteins was also assumed from similar amino acid compositions and the identical immunological properties of the two lipoproteins. However, some notable differences were found in the composition of the polypeptides. α-Lipovitellin contained much more polypeptide with 85,000 daltons than β-lipovitellin. Both apolipovitellins were found to be glycoprotein containing mannose, galactose, glucosamine and sialic acid. The sialic acid in α-lipovitellin exceeded that in β-lipovitellin by six times, though only slight differences were found in the content of neutral and amino sugars. The relatively acidic nature of a-lipovitellin compared with β-lipovitellin is attributed not only to the relative predominance in protein phosphorus but also to the predominance in the sialic acid. 相似文献
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Lech Celewicz Wojciech Urjasz Krzysztof Golankiewicz 《Nucleosides, nucleotides & nucleic acids》2013,32(9):951-966
Abstract A series of 3′-N-substituted 3′-amino-3′-deoxythymidine derivatives with alkyl, alkenyl and alkylaryl substituents was synthesized by two methods. The first method involved the reaction of 1-(2,3-dideoxy-3-0-mesyl-5-0-trityl-β-D-threo-pentofuranosyl)thymine with an appropriate amine. In the second method, 3′-amino-5′-0-trityl-3′-deoxy-thymidine served as a synthetic precursor which was reacted with an appropiate aldehyde or ketone followed by sodium borohydride reduction. An improved synthesis of 3′-amino-3′-deoxythymidine from 3′ -azido-5′-0-trityl-3′-deoxythymidine using sodium borohydride was also described. 相似文献
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Daisuke Yamane-Koshizawa Sotaro Fujii Takahiro Maruno Yuji Kobayashi Masaru Yamanaka Satoshi Wakai 《Bioscience, biotechnology, and biochemistry》2018,82(2):304-311
AVCP cytochrome c′ from mesophilic Allochromatium vinosum exhibits lower stability than a thermophilic counterpart, Hydrogenophilus thermoluteolus cytochrome c′ (PHCP), in which the six specific amino acid residues that are not conserved in AVCP are responsible for its stability. Here we measured the stability of AVCP variants carrying these specific residues instead of the original AVCP ones. Among the six single AVCP variants, all of which formed a dimeric structure similar to that of the wild-type, three were successfully stabilized compared with the wild-type, while one showed lower stability than the wild-type. In addition, the most stabilized and destabilized AVCP variants could bind CO, similar to the wild-type. These results indicated that mesophilic AVCP could be stabilized through specific three mutations modeled by the thermophilic counterpart, PHCP, without changing the CO binding ability. 相似文献
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Danny P. C. McGee Chandra Vargeese Yansheng Zhai Gary P. Kirschenheuter Alecia Settle Colleen R. Siedem 《Nucleosides, nucleotides & nucleic acids》2013,32(6):1329-1339
Abstract The synthesis of 2′-amino-2′-deoxypyrimidine 5′-triphosphates is described. The 2′-amino-2′-deoxyuridine 5′-triphosphate is obtained from uridine in four steps with 25% overall yield. The 2′-amino-2′-deoxycytidine 5′-triphosphate is obtained from uridine in seven steps with 13% overall yield. 相似文献
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Monica Donghi Barbara Attenni Cristina Gardelli Annalise Di Marco Fabrizio Fiore Claudio Giuliano Ralph Laufer Joseph F. Leone Vincenzo Pucci Michael Rowley Frank Narjes 《Bioorganic & medicinal chemistry letters》2009,19(5):1392-1395
A variety of new prodrugs of 2′-methyl cytidine based on acyloxy ethylamino phosphoramidates have been synthesized and tested in vitro and in vivo for their biological activity. Compared with the parent drug a 10- to 20-fold increase in formation of nucleotide triphosphate in rat and human hepatocytes could be achieved. 相似文献
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Abstract The structure of 2′,3′-didehydro-2′,3′-dideoxyguanosine was determined by X-ray crystallographic analysis of the complex with pyridine. The two independent nucleoside molecules have similar, commonly observed glycosyl link (x = -102.3° and -94.2°) and 5′-hydroxyl (y = 54.0° and 47.6°) conformations. The five-membered rings are very planar with r.m.s. deviations from planarity of less than 0.015 A. 2′,3′-Didehydro-2′,3′-dideoxyadenosine has a similar glycosyl link conformation but a different 5′-hydroxyl group orientation and a slightly less planar 5-membered ring. 相似文献
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Jari Hovinen Alex Azhayev Andrei Guzaev Harri Lönnberg 《Nucleosides, nucleotides & nucleic acids》2013,32(3-5):329-332
Abstract Preparation of 3′-deoxypsicothymidines bearing a tether group at O1′ is described. Selective protection of the primary hydroxy functions of the starting nucleoside is briefly discussed. 相似文献
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Abdesslem Faraj M. Abdelaziz El Alaoui Geraldine Pavia Gilles Gosselin Jean-Louis Imbach Raymond F. Schinazi 《Nucleosides, nucleotides & nucleic acids》2013,32(7-9):1287-1290
Abstract Several β-L-3′-substituted-3′-deoxythymidine were stereospecifically synthesized. None of these analogs inhibited HIV-1 nor HBV replication in vitro suggesting that these β-L-pyrimidine derivatives may not be efficiently phosphorylated inside the cells. 相似文献
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《Nucleosides, nucleotides & nucleic acids》2013,32(5-8):1657-1659
Abstract 2′-2H- and 3′-2H-CDP were synthesized from 5′-MMT-3′-O-TBDMS and 2′,5′- O-diTBDMS cytidine derivatives, respectively, by oxidation followed by acidic removal of 5′-protection, reduction with [NaBD(OAc)3] and finally displacement of a tosyl group by pyrophosphate. 相似文献
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Ahmed A. El-Barbary Ahmed I. Khodair Erik B. Pedersen Claus Nielsen 《Nucleosides, nucleotides & nucleic acids》2013,32(1-3):707-717
Abstract 3′-Amino and 5′-amino derivatives of hydantoin 2′-deoxynucleosides have been prepared from the corresponding 3′-phthalimido and 5′-azido nucleosides, respectively, which in turn were prepared by condensation of appropriate sugars with 5-benzylidenehydantoin. The amino nucleosides were tested for their potential activity against HIV and HSV. 相似文献
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María-José Camarasa Angel Díaz-Ortíz Ana Calvo-hateo Pederico G. De las Heras Jan Balzarini Erik de Clercq 《Nucleosides, nucleotides & nucleic acids》2013,32(5-6):837-840
Abstract A series of 3′-C-cyano-3′-deoxy and 3′-C-cyano-2′,3′-dideoxy-nucleoside analogues of thymidine, uridine, cytidine and adenosine have been prepared. Their antiviral activity was assessed in various assay systems and while none of the compounas proved specifically active against human immunodeficiency virus, some compounds had marked activity against other viruses. 相似文献