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Updated: Jun 8, 2026
15:22
Nucleoside Triphosphates - From Synthesis to Biochemical Characterization
Published on: April 3, 2014
Functional compromises among pH tolerance, site specificity, and sequence tolerance for a DNA-hydrolyzing
Ying Xiao1, Madhavaiah Chandra, Scott K Silverman
1Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
Biochemistry
|October 7, 2010
Summary
Researchers improved a DNA-cleaving enzyme (10MD5) for practical applications by enhancing its pH tolerance through in vitro evolution. New variants like 9NL27 show a trade-off between pH tolerance and sequence specificity.
Area of Science:
- Biochemistry
- Molecular Biology
- Catalysis
Background:
- Deoxyribozymes are DNA molecules with catalytic activity.
- The deoxyribozyme 10MD5 efficiently hydrolyzes single-stranded DNA but has a narrow pH optimum.
- Practical applications require enzymes with broader environmental tolerance.
Purpose of the Study:
- To optimize the deoxyribozyme 10MD5 for improved pH tolerance.
- To investigate the impact of pH tolerance on sequence and site specificity.
- To understand the interplay between enzyme tolerance and selectivity.
Main Methods:
- In vitro selection (evolution) was used to generate 10MD5 variants.
- DNA cleavage assays were performed to assess catalytic activity and specificity.
- pH profiles and substrate recognition sites were analyzed.
Main Results:
- Optimized deoxyribozyme variants with significantly broader pH tolerance were evolved.
- The evolved variants, such as 9NL27, exhibited a compromise between pH tolerance and site specificity.
- Altering Watson-Crick complementarity or expanding the recognition site influenced specificity.
Conclusions:
- In vitro evolution can enhance deoxyribozyme pH tolerance for practical applications.
- There is an inherent trade-off between deoxyribozyme pH tolerance and substrate selectivity.
- Findings offer insights into designing DNA-cleaving catalysts with tailored properties.
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