Organic solvent binding to crystalline subtilisin1 in mostly aqueous media and in the neat solvents.Schmitke, J.L., Stern, L.J., Klibanov, A.M.
(1998) Biochem Biophys Res Commun 248: 273-277
- PubMed: 9675126
- DOI: https://doi.org/10.1006/bbrc.1998.8937
- Primary Citation of Related Structures:
- PubMed Abstract:
The X-ray crystal structures of the protease subtilisin Carlsberg in 40% acetonitrile and in 20% dioxane have been determined to at least 2.3 A resolution, and their solvent binding patterns have been compared to those observed in the neat organic solvents. The structures of the protein in the two aqueous-organic mixtures are essentially the same as in pure water, acetonitrile, and dioxane. Interestingly, the enzyme-bound organic solvent molecules tend to congregate in the active site. Three of the five bound acetonitrile molecules observed in the structure of subtilisin in 40% acetonitrile are situated in the enzyme active site, as is the single enzyme-bound dioxane molecule observed in 20% dioxane (whose location is distinct from that of any bound acetonitrile molecule). Furthermore, the organic solvent molecules detected in the enzyme active site in the aqueous-organic mixtures are in the same locations as in the structures in the corresponding neat organic solvents.
Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139, USA.