| Autor: |
A L, Platonov, I I, Protasevich, I U, Evdokimov, N M, Akimenko, N A, Chebotareva |
| Rok vydání: |
1976 |
| Předmět: |
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| Zdroj: |
Molekuliarnaia biologiia. 10(2) |
| ISSN: |
0026-8984 |
| Popis: |
DNA-dependent heat effects accompanying mixing of water-salt (0.3 M NaCl) solutions of PEG and DNA within the range of PEG 10-50 mg/ml at 25 degrees C were determined by the method of difference microcalorimetry. It was found that, unlike optical and hydrodynamical methods, microcalorimetry makes it possible to detect some changes of the DNA-PEG system preceding formation of compact particles of DNA. In the studied range of DNA concentrations (up to 50 X 10(-3) MG/ML) the specific DNA-dependent heat effect is essentially independent of DNA concentration. It is negative and its absolute value increases from 0 to 5 cal/g of DNA in the PEG concentration range from 0 to 35-40 mg/ml after that the rate of its increase raises greatly and at PEG concentration of 50 mg/ml it is equal to 35 cal/g of DNA. It is suggested that the studied DNA dependent heat effects at low concentrations of PEG (less than 40 mg/ml) are caused by dehydration of DNA preceding its compactization. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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