Dipel was washed twice with 1 M NaCl and twice with deionized water (dH2O). The washed sediment was extracted overnight (18 h) with MOPS buffer [0.1 M 3-N-morpholinopropanesulfonic acid (Sigma) (pH 7.8) containing 0.5 M dithiothreitol (Boehringer Mannheim) and 1 M KSCN (Sigma)], the extract dialyzed against dH2O for 6 to 8 h with hourly changes of dH2O, and 17.5 g of (NH4)2SO4 100 ml−1of dialyzate was added to precipitate the protein. After 2 to 3 h, the precipitate was centrifuged at 27,000 g, resuspended in a minimum amount of dH2O, dialyzed for 8 h against dH2O with several changes of dH2O, and lyophilized.