Stellar activity is the phenomenon of a decrease or change in the specificity of restriction endonucleases , leading to indiscriminate cutting (restriction) of DNA during the in vitro reaction. Stellar activity occurs under conditions different from the optimum for a given enzyme. As a result of stellar activity, restriction occurs in noncanonical sites, sometimes a complete loss of specificity occurs.
The reasons for stellar activity can be:
- low ionic strength of the buffer solution,
- high pH
- high glycerol concentration (> 5% v / v),
- the presence of dimethyl sulfoxide (DMSO) ,
- the presence of Mg 2+ (in the case of HindIII endonuclease), etc. [1]
A high concentration of glycerol is especially important in laboratory practice, since commercially available restriction endonucleases are usually delivered in a buffer containing a significant amount of glycerol (50% v / v). Therefore, insufficient dilution of the enzyme solution can lead to stellar activity.
External links
- Star Activity - New England Biolabs
- Star Activity (Relaxation of Specificity) - Fermentas
- Star activity of restriction enzymes - a detailed list of stellar activities from TaKaRa
- H; Wei; Therrien, C; Blanchard, A; Guan, S; Zhu, Z. The Fidelity Index provides a systematic quantitation of star activity of DNA restriction endonucleases (English) // Nucleic Acids Research : journal. - 2008 .-- Vol. 36 , no. 9 . - P. e50 . - DOI : 10.1093 / nar / gkn182 . - PMID 18413342 .
Links
- ↑ Robinson, CR; Sliger, SG Molecular Recognition Mediated by Bound Water: A Mechanism for Star Activity of the Restriction Endonuclease EcoRI (Eng.) // Journal of Molecular Biology : journal. - 1993. - Vol. 234 , no. 2 . - P. 302-306 . - DOI : 10.1006 / jmbi.1993.1586 . - PMID 8230215 .