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931.
932.
The nucleotide sequence of a serine tRNA from Escherichia coli 总被引:10,自引:0,他引:10
933.
934.
935.
936.
Biosynthesis of the Actinomycin Chromophore: Incorporation of 3-Hydroxy-4-Methylanthranilic Acid into Actinomycins by Streptomyces antibioticus 总被引:1,自引:0,他引:1
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Actinomycin synthesis by washed mycelia of Streptomyces antibioticus has been conducted in the presence of 3-hydroxy-4-methylanthranilate-(carboxyl-14C). Incorporation of this compound into actinomycins has been observed, which constitutes further evidence that 3-hydroxy-4-methylanthranilate is an intermediate in actinomycin biosynthesis. The position of the incorporated label has been determined to be within the actinomycin chromophore, and the label appears to be equally distributed between both halves of the chromophore. Incidental to these findings was the observation that the 14C-labeled actinomycins were subject to rapid reabsorption by the organism with actinomycin V taken up preferentially to actinomycin IV. 相似文献
937.
938.
Aldose reductase and p-crystallin belong to the same protein superfamily as aldehyde reductase 总被引:12,自引:0,他引:12
D Carper C Nishimura T Shinohara B Dietzchold G Wistow C Craft P Kador J H Kinoshita 《FEBS letters》1987,220(1):209-213
Aldose reductase (EC 1.1.1.21) has been implicated in a variety of diabetic complications. Here we present the first primary sequence data for the rat lens enzyme, obtained by amino acid and cDNA analysis. We have found structural similarities with another NADPH-dependent oxidoreductase: human liver aldehyde reductase (EC 1.1.1.2). The identity between these two enzymes is 50%. Both enzymes share approx. 40-50% homology with p-crystallin, a major lens protein present only in the frog, Rana pipiens. We propose that aldose reductase, aldehyde reductase and p-crystallin are members of a superfamily of related proteins. 相似文献
939.
Protoplasts obtained from sycamore (Acer pseudoplatanus) cell suspensions were found to be highly intact. If the protoplasts were taken up and expelled through a fine nylon mesh, all the protoplasts were ruptured leaving the fragile amyloplasts largely intact. Aconitase hydratase (citrate [isocitrate] hydro-lyase, EC 4.2.1.3) activity of sycamore cells was associated with two protein fractions, one present in the cytosol while the second is of mitochondrial origin. Chromatography on DEAE-trisacryl did not separate the aconitase hydratase isoenzymes. EPR studies established that both isoenzymes exhibited an EPR signal at g = 2.03 once oxidized. 相似文献
940.
Abe Toshihiko; Tsuzuki Mikio; Kaplan Aaron; Miyachi Shigetoh 《Plant & cell physiology》1987,28(4):671-677
The requirement of sodium for growth of Anabaena variabilisM3 was investigated under low (0.04%) and high (1.5 or 5%) CO2conditions. The growth rates under both conditions were stronglyaffected by NaCl concentrations up to 0.5 mM in the medium.In the presence of 40 µM NaCl, the cells were not ableto grow under a low CO2 condition, but were able to grow undera high CO2 condition. The sodium requirement for growth wasdependent on pH: in the Na+-deficient condition, cells couldgrow at pH6.8, while no growth occurred at pH 8.2, suggestingthat the requirement of Na+ for growth observed in the low CO2condition can be substituted for by a lower pH. In the presence of 20 mM NaCl at pH 7.8, 14CO2 as well as H14CO3were actively transported into the cells which had been grownin air. In contrast, the transport of both of these inorganiccarbon (IC) species was suppressed under the Na+-deficient condition.These results suggest that sodium is required for the stimulationof transport of IC during photosynthesis. This is one of thereasons why Na+ is required for the growth of Anabaena underordinary air and alkaline conditions. (Received September 27, 1986; Accepted March 26, 1987) 相似文献