| Autor: |
Feig AL; Department of Chemistry and Biochemistry, University of Colorado, Boulder 80309, USA., Ammons GE, Uhlenbeck OC |
| Jazyk: |
angličtina |
| Zdroj: |
RNA (New York, N.Y.) [RNA] 1998 Oct; Vol. 4 (10), pp. 1251-8. |
| DOI: |
10.1017/s1355838298980943 |
| Abstrakt: |
The technique of cryoenzymology has been applied to the hammerhead ribozyme in an attempt to uncover a structural rearrangement step prior to cleavage. Several cryosolvents were tested and 40% (v/v) methanol in water was found to perturb the system only minimally. This solvent allowed the measurement of ribozyme activity between 30 and -33 degrees C. Eyring plots are linear down to -27 degrees C, but a drastic reduction in activity occurs below this temperature. However, even at extremely low temperatures, the rate is still quite pH dependent, suggesting that the chemical step rather than a structural rearrangement is still rate-limiting. The nonlinearity of the Eyring plot may be the result of a transition to a cold-denatured state or a glassed state. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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