1be6
From Proteopedia
TRANS-CINNAMOYL-SUBTILISIN IN ANHYDROUS ACETONITRILE
Structural highlights
FunctionSUBC_BACLI Subtilisin is an extracellular alkaline serine protease, it catalyzes the hydrolysis of proteins and peptide amides (Ref.4, PubMed:11109488). Shows high specificity for aromatic and hydrophobic amino acids in the P1 substrate position (PubMed:11109488). May play an important role in the degradation of feather keratin (PubMed:11109488).[1] [2] Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe 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. Comparison of x-ray crystal structures of an acyl-enzyme intermediate of subtilisin Carlsberg formed in anhydrous acetonitrile and in water.,Schmitke JL, Stern LJ, Klibanov AM Proc Natl Acad Sci U S A. 1998 Oct 27;95(22):12918-23. PMID:9789015[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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