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41.
Douglas E Bassett Jr Munira A Basrai Carla Connelly Katherine M Hyland Katsumi Kitagawa Melanie L Mayer Dwight M Morrow Andrew M Page Vicente A Resto Robert V Skibbens Philip Hieter 《Current opinion in genetics & development》1996,6(6):763-766
The completion of the genome sequence of the budding yeast Saccharomyces cerevisiae marks the dawn of an exciting new era in eukaryotic biology that will bring with it a new understanding of yeast, other model organisms, and human beings. This body of sequence data benefits yeast researchers by obviating the need for piecemeal sequencing of genes, and allows researchers working with other organisms to tap into experimental advantages inherent in the yeast system and learn from functionally characterized yeast gene products which are their proteins of interest. In addition, the yeast post-genome sequence era is serving as a testing ground for powerful new technologies, and proven experimental approaches are being applied for the first time in a comprehensive fashion on a complete eukaryotic gene repertoire. 相似文献
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Miguel Arroyo José María Sánchez-Montero José Vicente Sinisterra 《Biotechnology Techniques》1996,10(4):263-266
Summary We describe a qualitative method to predict the pre-equilibration aw, system value in which, covalent immobilized lipase B from Candida antarctica to sepharose and silica, displayed best synthetic activity. The methodology is based in the analysis of the water adsorption isotherms of the biocatalyst in air and in the organic solvent. The biocatalyst is active at pre-equilibration aw values higher than the divergence point between both isotherms. In addition, native and immobilized lipase display highest activity if the biocatalyst is pre-equilibrated at aw=P point. For preparative purposes, the validity of the method was proved in the esterification of racemic 2-(4-isobutyl phenyl) propionic acid with 1-propanol in isooctane at long reaction time. 相似文献
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46.
A linkage map with RFLP and isozyme markers for almond 总被引:12,自引:0,他引:12
M. A. Viruel R. Messeguer M. C. de Vicente J. Garcia-Mas P. Puigdomènech F. Vargas P. Arús 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1995,91(6-7):964-971
Inheritance and linkage studies were conducted with seven isozyme genes and 120 RFLPs in the F1 progeny of a cross between almond cultivars Ferragnes and Tuono. RFLPs were detected using 57 genomic and 43 cDNA almond clones. Eight of the cDNA probes corresponded to known genes (extensin, prunin (2), -tubulin, endopolygalacturonase, oleosin, actin depolymerizing factor and phosphoglyceromutase). Single-copy clones were found more frequently in the cDNA (65%) than in the genomic libraries (26%). Two maps were elaborated, one with the 93 loci heterozygous in Ferragnes and another with the 69 loci heterozygous in Tuono. Thirty-five loci were heterozygous in both parents and were used as bridges between both maps. Most of the segregations (91%) were of the 11 or 1111 types, and data were analyzed as if they derived from two backcross populations. Eight linkage groups covering 393 cM in Ferragnes and 394 in Tuono were found for each map. None of the loci examined in either map was found to be unlinked. Distorted segregation ratios were mainly concentrated in two linkage groups of the Ferragnes map. 相似文献
47.
Fernández José A. Clavero Vicente Villalobos José A. Niell F. Xavier 《Hydrobiologia》1997,344(1-3):205-214
Phosphorus fluxes in phytoplankton, between intracellular andexternal compartments have been measured, in the epilimnion ofatemperate eutrophic reservoir, by means of phosphorusdepletionexperiments performed in situ. Flow rates betweencompartments were plotted against the phosphorus concentrationofthe compartments' origin of the flows and fitted to saturationfunctions.A value of phosphorus cell subsistence quota for the wholecommunity has been computed from the X-intercept values ofeveryfunction. The obtained figures are 10–100 times higher,dependingon the reference value, than those measured running theclassicalsingle species growth response experiments in chemostats.We propose a model using five compartments and a series offlowrates between them in order to simulate the general phosphoruscycling in freshwater phytoplankton. Short term simulation ofphosphorus content in every compartment shows a fluctuatingpatternaround rates of equilibrium, in agreement with the pattern ofvariation observed in situ for the selectedcompartments. 相似文献
48.
T. Macedo C. A. Fontes Ribeiro D. Cotrim P. Tavares M. T. Morgadinho M. Caramona M. T. Nunes Vicente L. Rodrigues M. G. Cardoso M. L. Keating 《Molecular neurobiology》1995,11(1-3):21-29
This work evaluated in a population of heroin and heroin plus cocaine human addicts:
- Norepinephrine (NE), epinephrine (Epi), and 3-methoxy-4-hydroxyphenylglycol (MHPG) (the principal metabolite of brain NE) plasma levels;
- Monoamine oxidase (MAO) activity; and
- 3H-imipramine specific binding to the amine carrier in platelets.
49.
Carbamoyl phosphate synthetase I (ammonia; E C 6.3.4.16) was purified from the liver of Rana catesbeiana (bullfrog). Crystals of the protein have been obtained at 22°C by the hanging drop vapor diffusion technique, with polyethylene glycol as precipitant. Tetragonal crystals of about 0.3 × 0.3 × 0.7 mm diffract at room temperature to at least 3.5 Å using a conventional source and are stable to X-radiation for about 12 h. Therefore, these crystals are suitablefor high resolution studies. The space group is P41212 (or its enantiomorph P43212), with unit cell dimensions a = b = 291.6 Å and c = 189.4 Å. Density packing considerations areconsistent with the presence of 4-6 monomers (Mr of the monomer, 160,000) in the asymmetric unit. Amino-terminal sequence of the enzyme and of a chymotryptic fragment of 73.7 kDa containing the COOH-terminus has been obtained. The extensive sequence identity with rat and human carbamoyl phosphate synthetase I indicates the relevance for mammals of structural data obtained with the frog enzyme. © 1995 Wiley-Liss, Inc. 相似文献
50.
The membrane-bound ATPase activity from two substrains ofMicrococcus lysodeikticus, designated as A and B, was inhibited by antibodies raised against the two forms of purified F1-ATPase. Form B of the enzyme, which behaved as a poorer immunogen than form A, also showed less reactivity as an antigen, independent of the physical state of the F1-ATPase form. Antibodies were raised against the two major subunits ( and ) isolated fromM. lysodeikticus F1-ATPase form A, which was the most stable form of the enzyme. Anti-(-subunit) serum strongly inhibited the ATPase activity of membrane-bound ATPase but showed little inhibition of the purified, soluble F1-ATPase. The anti-(-subunit) serum inhibited the soluble F1-ATPase, but to a lesser extent than the membrane-bound enzyme. In any event, the effect of anti- antibodies on the membrane-bound ATPase was smaller than that of anti- antibodies. It was postulated that the subunit ofM. lysodeikticus F1-ATPase plays an essential and regulatory role in the expression of the immunochemical properties of the protein. 相似文献