| Project/Area Number |
58420054
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| Research Category |
Grant-in-Aid for General Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
生物物性学
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| Research Institution | Institute of Space and Astronautical Science |
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Principal Investigator |
SHIMIZU Mikio 宇宙科学研究所, その他, 教授 (90017179)
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| Project Period (FY) |
1983 – 1985
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| Project Status |
Completed (Fiscal Year 1985)
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| Budget Amount *help |
¥30,800,000 (Direct Cost: ¥30,800,000)
Fiscal Year 1985: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1984: ¥14,000,000 (Direct Cost: ¥14,000,000)
Fiscal Year 1983: ¥14,800,000 (Direct Cost: ¥14,800,000)
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| Keywords | tRNA / Genetic Code / Specific Molecular Recognition / Amino Acid / Modified Base / Fluorescence / Circular Dichroism / 円二色性偏光 / 紫外分光 |
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| Research Abstract |
It is shown by molecular building and by semi-empirical calculations that complex of four nucleotides (C4N) composed of three anticodon bases and a discriminator base on a tRNA has a pocket on it to accept the cognate amino acid. This relationship could be the molecular basis of the genetic code. We have attempted to detect the specific interaction between tRNA (or oligonucleotide) and amino acid by using three spectroscopic methods such as ultraviolet absorption, fluorescence, and circular dichroism: In the C4N model, it can be predicted that <tRNA^(Asp)> and <tRNA^(Glu)> can discriminate their cognate amino acids without the discriminator base, while <tRNA^(Phe)> not. <tRNA^(Asp)> and <tRNA^(Glu)> have queosine and m n <m^5> <S^2> U as their first anticodon bases, respectively. By adding the cognate amino acid little by little to the tRNA solutions, the specific interaction of these tRNAs with the cognate amino acids has been detected by checking the saturation effect. The affinity coefficient were measured to be of the order of 100 <M^(-1)> , fairly large. On the other hand, Poerschke of West Germany could not find the specificity for <tRNA^(Phe)> , in accord with C4N theory. The precise ultraviolet absorbance spectroscopy was applied to the cases of anticodon-like dinucleoside monophosphates to find the specific interaction with the amino acids, their amides, and their methyl esters. The complet specificity was found only in the case of neutral amino acids. The above experiments appears to suggest that the genetic code is nothing but the specific interaction table between the nucleic acid bases and the amino acid.
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