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1.
Summary Imidazolides of dinucleotides such as ImpApA can be formed from the corresponding dinucleotides in a two-stage process, which gives up to 15% yields under potentially prebiotic conditions. First a solution of the dinucleotide and sodium trimetaphosphate is dried out at constant temperature and humidity. This produces polyphosphates such as pnApA in excellent yield (80%). The products are dissolved in water, imidazole is added, and the solution is dried out again. This yields the 5-phosphorimidazolides.Abbreviations P3! trimetaphosphate - A adenosine - U uridine - EDTA ethylenediaminetetraacetic acid - Ap adenosine 2(3)-phosphate - Ap! adenosine cyclic 2:3-phosphate - pA adenosine 5-phosphate - pA2p adenosine 2, 5-diphosphate - pA3p adenosine 3, 5-diphosphate - pAp! 5-phospho-adenosine cyclic 2:3-phosphate - ATP adenosine 5-triphosphate - ImpA adenosine 5-phosphorimidazolide - A2pA adenylyl-[25]-adenosine - A3pA adenylyl-[35]-adenosine - A2pU adenylyl-[25]-uridine - A3pU adenylyl-[35]-uridine - pA2pA 5-phosphoadenylyl-[25]-adenosine - pA3pA 5-phospho-adenylyl-[35]-adenosine - pA2pU 5-phospho-adenylyl-[25]-uridine - pA3pU 5-phospho-adenylyl-[35]-uridine - pApN (N= A, U) 5-phosphate of a dinucleoside phosphate - pnApN (N = A, U; n = 2, 3, 4.) 5-polyphosphate of a dinucleoside phosphate - ImpA2pA imidazolide of pA2pA - ImpA3pA imidazolide of pA3pA - ImpA2pU imidazolide of pA2pU - ImpA3pU imidazolide of pA3pU - ImpApN imidazolide of pApN  相似文献   

2.
The molecular basis of HbH disease in Taiwan   总被引:1,自引:0,他引:1  
Summary We have determined the molecular characteristics of -thalassemia in 12 HbH subjects from Taiwan by restriction endonuclease mapping with -and -specific probes. We have found four types of defects in the -thalassemia-2 genetic determinant: 3.7 type I; 4.2; CS; and T. All HbH subjects carried the ——SEA genotype in the -thalassemia-1 determinant. At least two different subtypes of ——SEA genotype were observed in this study.  相似文献   

3.
Summary In order to localize a gene for resistance to Barley Yellow Mosaic Virus (BaYMV) of German resistant varieties, cvs. Ogra and Sonate were crossed to a complete trisomic (2n=2x+1=15) set of Shin Ebisu 16. Tests for resistance in F2 strongly support the conclusion that the German gene for resistance to BaYMV is located on barley chromosome 3.  相似文献   

4.
Summary We present ab initio calculations of the Fermi contact term and experimental correlations of six coupling constants, 3JH N H , 1JC H , 2JCH , 1JC N, 2JC N and 1JCN, in a peptide as functions of the backbone dihedral angles, and . Given estimates of experimental uncertainties, we find semiquantitative experimental correlations for 3JH N H , 1JC N and 2JC N, qualitative correlations for 1JC H and 2JCH , but no experimental correlations of practical utility for 1JCN, owing to its complex dependence on at least four dihedral angles. Errors in the estimation of dihedral angles from X-ray crystallographic data for proteins, which result from uncertainties in atom-to-atom distances, place substantial limitations on the quantitative reliability of coupling constant calculations fitted to such data. In the accompanying paper [Edison, A.S. et al., J. Biomol. NMR, 4, 543–551] we apply the results of the coupling constant calculations presented here to the estimation of and angles in staphylococcal nuclease from experimental coupling constants.Abbreviations AO atomic orbital - BPTI basic pancreatic trypsin inhibitor (bovine) - CI-2 chymotrypsin inhibitor 2 - E.COSY exclusive correlation spectroscopy (Griesinger et al., 1986) - nJAB single bond (n=1), geminal (n=2), or vicinal (n=3) coupling constant between nuclei A and B - LCAO linear combination of atomic orbitals - NBO natural bond orbital - n lone pair orbitals - bonding orbitals - * antibonding orbitals - dihedral angle or molecular orbital wave function; r2, correlation coefficient - RHF restricted Hartree-Fock; rmsd, root-mean-square deviation - 3-21G and 6-31G* molecular orbital basis set designations (Hehre et al., 1986)  相似文献   

5.
Summary Genetic analysis of heading date and spikelet number was carried out in the common wheat (Triticum aestivum L.) multispikelet line Noa, by using the monosomic series of the regular line Mara. Noa's high number of spikelets was found to be controlled by a recessive major gene on chromosome 2D; a slight reduction in spikelet number was induced by another recessive gene on Noa's 7A chromosome. Noa's late heading date was found to be controlled by two recessive genes, located on chromosome 2D (a major effect) and 6B (a minor effect). The nature of the genes located on Noa's 2D chromosome and the relationship between spikelet number and heading date are discussed.  相似文献   

6.
Summary Soluble lead salts and a number of lead-containing minerals catalyze the formation of oligonucleotides from nucleoside 5-phosphorimidazolides. The effectiveness of lead compounds correlates strongly with their solubility. Under optimal conditions we were able to obtain 18% of pentamer and higher oligomers from ImpA. Reactions involving ImpU gave smaller yields.Abbreviations A adenosine - U uridine - Im imidazole - MeIm 1-methyl-imidazole - EDTA ethylenediaminetetraacetic acid - pA adenosine 5-phosphate - pU uridine 5-phosphate - Ap adenosine cyclic 2:3-phosphate - ATP adenosine 5-triphosphate - AppA P1,P2-diadenosine 5-diphosphate - pNp (N = A,U) nucleotide 2(3), 5-diphosphate - ImpA adenosine 5-phosphoreimidazolide - ImpU uridine 5-phosphorimidazolide - A 2pA adenylyl-[25]-adenosine - A 3pA adenylyl-[35]-adenosine - pA 2pA 5-phospho-adenylyl-[25]-adenosine - pA 3pA 5-phospho-adenylyl-[35]-adenosine - pUpU 5-phospho-uridylyl-uridine - pApU 5-phospho-adenylyl-uridine - pUpA 5-phospho-uridylyladenine - (pA)n (n, 2,3,4,) oligoadenylates with 5 terminal phosphate - ImpApA 5-phosphorimidazolide of adenylyl adenosine - (pA) 5+ pentamer and higher oligoadenylates with 5 terminal phosphate - (Ap)nA (n = 2,3,4) oligoadenylates without terminal phosphates In the following we do not specify the nature of the internucleotide linkageIn the following we do not specify the nature of the internucleotide linkage  相似文献   

7.
We found that -caprolactam is a new powerful inducer for the formation of Rhodococcus rhodochrous J1 nitrilase. When Rhodococcus rhodochrous J1 cells were cultivated at 28°C for 120 h in a nutrient medium supplemented with 0.5% (w/v) -caprolactam, an enormous amount of nitrilase was formed in the cells which corresponded to approximately 30% of all soluble protein. The level of -caprolactam in the culture broth barely decreased in the course of cultivation. -Butyrolactam and -valerolactam also caused effective induction. The induction of nitrilase formation by -caprolactam was also observed in some other Rhodococcus strains.  相似文献   

8.
Summary To obtain information on the dynamic and quantitative aspects of displospory in a facultative apomict,Allium tuberosum (2n = 32), we cytologically observed the entire course of female meiosis and embryosac development in cv Tender-Pole by the clearing-staining-squash method. A time-table of its course was constructed in terms of bud length and days pre-anthesis. Chromosome threads were observed in pairs at the earliest stage of meiosis, after which 32 autobivalents developed. Thus, endoreduplication must have occurred during premeiotic interphase or at the onset of female meiosis. Such endoreduplicational meiosis also occurred on the male side, though the frequency (3.9%) was much lower than that on the female side (80%). The degree of diplospory calculated as the percentage of reduplicated embryo-sac mother cells varied to some extent among six cultivars: Huhehaote and Manchuria showed the highest degree of diplospory (98%), and Kaohsiung the lowest (76%).  相似文献   

9.
Summary Genetic analysis for leaf rust reaction of two widely adapted cultivars, Sonalika and WL 711, has been done using 21 near isogenic Lr lines and rust culture IL004 — avirulent on the two cultivars and all the Lr lines used. The segregation pattern in the F2 generation indicated the presence of a recessive gene in Sonalika and of a dominant gene in WL 711. These genes in cultivars Sonalika and WL 711 have been identified as Lr 11 and Lr 13, respectively. Gene Lr 13 is no longer effective in WL 711 but it continues to give field resistance in the backgrounds of Chris, Prelude and Thatcher. There has been no significant change in the virulence spectrum of the leaf rust pathogen in India with the release of WL 711. High susceptibility of WL 711 seems to be due to the evolution of more aggressive forms of the pathogen to this cultivar. The gene Lr 11, which behaves as a recessive in Sonalika, was effective against leaf rust when this cultivar was released. The high susceptibility of Sonalika is probably due to an increase in the frequency of race 77 virulent on Lr 11. Lr 11 has shown a dominance reversal in the background of Sonalika. Present results suggest that interaction of resistance genes with the background genotype must be studied for their effective use in breeding programme.  相似文献   

10.
Summary Immunohistochemical distributions of carbohydrate antigens based on the type 2 chain in normal as well as fetal and neoplastic tissues of human gastrointestinal tract were investigated with a monoclonal antibody (MAb) H11 (specific for type 2 chain) alone and in combination with the two MAbs MSG15 (for 26 sialylated type 2 chain) and IB9 (for the 26 sialylated type 2 chain and glycoproteins having NeuAc26GalNAc), and 188C1 (for short- and long-chain Lex antigens) and FH2 (for the long-chain Lex antigen). In the pyloric mucosa of secretors, the type 2 chain is oncodevelopmentally expressed, but in non-secretors it is detected in surface mucous cells of normal gastric mucosa. The 26 sialylation, which is confined to endocrine cells of normal pyloric mucosa, occurs in fetal and carcinoma tissues. Irrespective of the secretor status, the short- and the long-chain Lex antigens can be detected in mature and immature glandular mucous cells of normal gastric mucosa, respectively; both antigens are also expressed in fetal and carcinoma tissues. In the colon, the type 2 chain and its 26 sialylated counterpart are expressed in an oncodevelopmental manner. The short- and the long-chain Lex antigens are significantly enhanced in colonic carcinoma. The glycoproteins with NeuAc26GalNAc residues appear in gastric and colonic carcinoma as well as intestinalized gastric mucosa and transitional mucosa. Thus, some of these antigens were distinctively expressed in certain epithelial cells lining the normal gastrointestinal tract depending on maturation and patients' secretor status, and some were oncodevelopmental or carcinoma-associated antigens of the human gastrointestinal tract.Abbreviations Fuc fucose - Gal galactose - GalNAc N-acetylgalactosamine - Glc glucose - GlcNAc N-acetylglucosamine - MAb monoclonal antibody - NeuAc N-acetylneuraminic acid - PBS phosphate-buffered saline  相似文献   

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