PEDS Advance Access originally published online on June 8, 2004
Protein Engineering Design and Selection 2004 17(4):333-339; doi:10.1093/protein/gzh045
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Stabilized variant of Streptomyces subtilisin inhibitor and its use in stabilizing subtilisin BPN'
1Corporate Research Division, Procter & Gamble Co., Miami Valley Laboratories, PO Box 538707, Cincinnati, OH 45253-8707 and 2Department of Chemistry, Purdue University, West Lafayette, IN 47907-1393, USA
3 To whom correspondence should be addressed. E-mail: saunders.cw{at}pg.com
Protein protease inhibitors could potentially be used to stabilize proteases in commercial products such as liquid laundry detergents. However, many protein protease inhibitors are susceptible to hydrolysis inflicted by the protease. We have engineered Streptomyces subtilisin inhibitor (SSI) to resist proteolysis by adding an interchain disulfide bond and removing a subtilisin cleavage site at leucine 63. When these stabilizing changes were combined with changes to optimize the affinity for subtilisin, the resulting inhibitor provided complete protease stability for at least 5 months at 31°C in a subtilisin-containing liquid laundry detergent and allowed full recovery of the subtilisin activity upon the dilution that occurs in a North American washing machine.
Received January 13, 2004; revised May 13, 2004; accepted May 13, 2004.
Edited by Robin Offord