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71.
I. Marta Evans Ronald R. D. Croy Philippa Hutchinson Donald Boulter Peter I. Payne Margaret E. Gordon 《Planta》1979,144(5):455-462
Polyribosomes which have template activity in the wheat germ system have been isolated from developing pea seeds. Some of the translation products have identical mobilities to the vicilin and legumin subunits by SDS-PAGE. Certain products were specifically immunoprecipitated with antisera prepared against purified vicilin and legumin fractions. Various RNA fractions including poly A-rich RNA have also been isolated from polyribosomes and shown to direct the synthesis of polyripeptides whose properties are similar to the storage protein subunits. The results are discussed in relationship to other investigations with seed storage protein biosynthesis in vitro.Abbreviations DTT
dithiothreitol
- SDS-PAGE
SDS-polyacrylamide gel electrophoresis
- TCA
tricarboxylic acid 相似文献
72.
C. A. Arce Marta E. Hallak J. A. Rodriguez H. S. Barra R. Caputio 《Journal of neurochemistry》1978,31(1):205-210
Abstract— Incorporation of [14 C]tyrosine into the C-terminal position of α-tubulin of rat brain cytosol was 10-fold higher for non-assembled than for assembled tubulin. The incorporation into tubulin from disassembled microtubules was higher than into non-assembled tubulin; therefore, the low incorporation into microtubules was not due to a lower acceptor capacity of their tubulin constituent.
[14 C]Tyrosine was released from assembled and non-assembled [14 C]tyrosinated tubulin by the action of an endogenous carboxypeptidase. Release from non-assembled tubulin was shown by incubating a tubulinyl-[14 C]tyrosine preparation in the presence of CaCl2 at a concentration that abolished microtubule formation. Release from microtubules was inferred from the observation that the percentages of [14 C]tyrosine released and the decrease of the specific radioactivity of the recovered microtubules were practically identical and did not change after a 10-fold dilution of the incubated microtubules.
[3 H]Phenylalanine was released from a preparation of tubulinyl-[3 H]phenylalanine also by an enzymatic activity.
The capacity of a tubulin preparation to incorporate tyrosine was increased 43% by pre-treatment with endogenous carboxypeptidase.
Tubulin tyrosinated in vitro was assembled to the same extent as native tubulin. After a mixture of tubulinyl-[14 C]tyrosine and tubulinyl-[3 H]phenylalanine was partially assembled, the ratio of 14 C/3 H found in the microtubules was the same as in the non-assembled tubulin fraction. 相似文献
[
[
The capacity of a tubulin preparation to incorporate tyrosine was increased 43% by pre-treatment with endogenous carboxypeptidase.
Tubulin tyrosinated in vitro was assembled to the same extent as native tubulin. After a mixture of tubulinyl-[
73.
Extrachromosomal DNA in Thiobacillus A2 总被引:1,自引:0,他引:1
74.
75.
The pollination biology and breeding system of Vellozia squamata (Velloziaceae), a species of cerrado vegetation in Central Brazil, were studied. V. squamata is unusual in being pollinated by a few, generalist bee species despite having very large flowers, and having a distinctive pulsed flowering phenology. The species is self-incompatible but with a late-acting, post-fertilization rejection mechanism. 相似文献
76.
In vivo and in vitro effects of boron on the plasma membrane proton pump of sunflower roots 总被引:3,自引:0,他引:3
Marta Roldán rés Belver Pilar Rodríguez-Rosales Nuria Ferrol Juan Pedro Donaire 《Physiologia plantarum》1992,84(1):49-54
The effect of boron excess and deficiency on H+ efflux from excised roots from sunflower ( Heliarahus annuus L. cv. Enano) seedlings and on plasma membrane H+ -ATPase (EC 3.6.1.35) in isolated KI-washed microsomes has been investigated. When seedlings were grown in media with toxic levels of H3 BO3 (5 m M ) or without added boron and exposed to light conditions, an inhibition of the capacity for external acidification by excised roots was observed as compared to roots from seedlings grown with optimal H3 BO3 concentration (0.25 m M ). Toxic and deficient boron conditions also inhibited the vanadate-sensitive H+ -ATPase of microsomes isolated from the roots. The mechanism of boron toxicity was investigated in vitro with microsorne vesicles. A strong effect of boron on the vanadate-sensitive, ATP-dependent H+ transport was found, but the vanadate-sensitive phospho-bydrolase activity was not affected. These results suggest that boron could exert an effect on the plasma membrane properties, directly or indirectly regulating, proton transport. 相似文献
77.
Manuel Rico Jorge Santoro Carlos González Marta Bruix José Luis Neira José Luis Nieto José Herranz 《Journal of biomolecular NMR》1991,1(3):283-298
Summary A method is proposed to generate initial structures in cases where the distance geometry method may fail, such as when the set of1H NMR NOE-based distance constraints is small in relation to the size of the protein. The method introduces an initial correlation between the and backbone angles (based on empirical observations) which is relaxed in later stages of the calculation. The obtained initial structures are refined by well-established methods of energy minimization and restrained molecular dynamics. The method is applied to determine the solution structure of Ribonuclease A (124 residues) from a NOE basis consisting of 467 NOE cross-correlations (97 intra-residue, 206 sequential, 23 medium-range and 141 long-range) obtained at 360 MHz. The global shape and backbone overall fold of the eight final refined structures are close to those shown by the crystal structure. A meaningful difference in the positioning of the catalytically important His119 side chain in the solution and crystal structures has been detected. 相似文献
78.
79.
NAD-linked lactate, malate, glycerophosphate, alcohol and nonspecific dehydrogenases, aspartate aminotransferases, and soluble esterases from extracts of tissues of individuals from a wild population of Calomys musculinus (Rodentia, Cricetidae) have been analyzed by means of starch gel electrophoresis and specific staining. Allelic frequencies and heterozygosity have been determined. Mendelian inheritance of some of the variants detected was confirmed by breeding experiments. Ten out of fifteen (66.6%) of the genetic loci investigated presented polymorphism. Mean heterozygosity per locus was very high (H=0.2014, se 0.046).This work has been supported, in part, by grants from the Secretaria de Ciencia y Tecnología de la Nación (National Program for Endemic Diseases) and from the Fundación Emilio Ocampo. C. N. G. is a Fellow and A. B. a Career Investigator of the Consejo Nacional de Investigaciones Científicas y Técnicas of Argentina. 相似文献
80.