1BE6

TRANS-CINNAMOYL-SUBTILISIN IN ANHYDROUS ACETONITRILE

Summary for 1BE6

• Entry DOI: 10.2210/pdb1be6/pdb
• Descriptor: SUBTILISIN CARLSBERG, CALCIUM ION, PHENYLETHYLENECARBOXYLIC ACID, ... (5 entities in total)
• Functional Keywords: serine protease, organic solvent, acyl-enzyme
• Biological source: Bacillus licheniformis
• Cellular location: Secreted: P00780
• Total number of polymer chains: 1
• Total formula weight: 27987.06

Authors

Schmitke, J.L.,Stern, L.J.,Klibanov, A.M. (deposition date: 1998-05-20, release date: 1998-10-14, Last modification date: 2024-10-16)

Primary citation

Schmitke, J.L.,Stern, L.J.,Klibanov, A.M.
Comparison of x-ray crystal structures of an acyl-enzyme intermediate of subtilisin Carlsberg formed in anhydrous acetonitrile and in water.
Proc.Natl.Acad.Sci.USA, 95:12918-12923, 1998

PubMed Abstract: The x-ray crystal structures of trans-cinnamoyl-subtilisin, an acyl-enzyme covalent intermediate of the serine protease subtilisin Carlsberg, have been determined to 2.2-A resolution in anhydrous acetonitrile and in water. The cinnamoyl-subtilisin structures are virtually identical in the two solvents. In addition, their enzyme portions are nearly indistinguishable from previously determined structures of the free enzyme in acetonitrile and in water; thus, acylation in either aqueous or nonaqueous solvent causes no appreciable conformational changes. However, the locations of bound solvent molecules in the active site of the acyl- and free enzyme forms in acetonitrile and in water are distinct. Such differences in the active site solvation may contribute to the observed variations in enzymatic activities. On prolonged exposure to organic solvent or removal of interstitial solvent from the crystal lattice, the channels within enzyme crystals are shown to collapse, leading to a drop in the number of active sites accessible to the substrate. The mechanistic and preparative implications of our findings for enzymatic catalysis in organic solvents are discussed.

PubMed: 9789015
DOI: 10.1073/pnas.95.22.12918

Experimental method

X-RAY DIFFRACTION (2.15 Å)