Acylation of subtilisin with long fatty acyl residues affects its activity and thermostability in aqueous medium.

Subtilisin Carlsberg has been artificially hydrophobized by acylation with octanoyl or palmitoyl chlorides. Samples with several degrees of substitution were obtained. Hydrophobization facilitates in some cases the binding of synthetic or natural substrates. Furthermore, derivatized subtilisins show improved thermal stability (15-fold at 45 degrees C) in aqueous solution. As a result, octanoyl-subtilisin exhibits enhanced thermostability without losing biological activity.