Sandbox Reserved 987: Difference between revisions

The wild-type cocaine esterase is not stable at physiological temperature, which poses a problem for its use as a pharmaceutical drug. Mutations have been conducted in order to increase its thermostability. In vivo testing showed the wild-type having a 11 min half-life. A mutant having its threonine swapped for a arginine at position 172 (T172R) was found to last 9 times as long, and a mutant that further had its glycine swapped for a glutamine (T172R/G173Q) was found to last 24 times as long (~4h 20m)^{<ref>Gao D., Narasimhan D. L., Macdonald J., Brim R., Ko M., Landry D. W., Woods J. H., Sunahara R. K., Zhan C. (2009) Thermostable variants of cocaine esterase for long-time protection against cocaine toxicity. Mol. Pharmacol. 75, 318-323.</ref>} Another mutant that has been explored is the L169K/G173Q mutant. This showed an in vivo half life of ~2h 20m.^{<ref>Brim R. L., Nance M. R., Youngstrom D. W., Narasimhan D., Zhan C. G., Tesmer J. J. G., Sunahara, R. K., Woods J. W. (2010) A Thermally Stable Form of Bacterial Cocaine Esterase: A Potential Therapeutic Agent for Treatment of Cocaine Abuse. Mol. Pharmacol. 77(4), 593-600.</ref>} L169K causes a large increase in half life up to 9h 30m, but reduced catalytic efficiency 4.5 fold.^{<ref>Narasimhan D., Nance M.R., Gao D., Ko M.C., Macdonald J., Tamburi P., Yoon D., Landry D.M., Woods J.H., Zhan C.G., Tesmer J.J., Sunahara R.K. (2009) Structural analysis of thermostabilizing mutations of cocaine esterase. Protein Eng. Des. Sel. 23:537-547.</ref>}