Oral Presentation 6-03

Barbara R. Evans and Jonathan Woodward

Chemical Technology Division
Oak Ridge National Laboratory
P. O. Box 2008
Oak Ridge, Tennessee 37831-6194

Telephone: (865) 241-3185; Fax: (865) 574-1275; E-mail: evansb@ornl.gov

A cellulose-binding domain (CBD) from the Cellulomonas fimi endoglucanase CenA was produced as a recombinant protein with a C-terminal 6-histidine peptide from a commercial expression vector (Novagen, Inc., Madison, WI). The histidine region was used to complex the transition metal ions copper, iron, and nickel with the CBD. Metal complexes, including microperoxidase-8, were covalently attached with carbodiimide. The oxidative properties of these metallized CBDs and their interactions with cellulose and cellulases were investigated. The attached metals retained their specific oxidative activities. Metallization did not interfere with cellulose binding. Binding of the metallized CBDs and control CBD to different types of cellulose fibers was examined. The effect of metallization on the dispersion of cellulose fibers was examined for samples that included filter paper, cotton linters, and newsprint. The effects of adding oxidants and reductants to the reactions of the metallized CBDs with cellulose fibers were investigated. Cellulose samples were hydrolyzed by whole cellulases in the presence of control CBD or metallized CBDs. Competition for binding sites was observed between cellulases and control CBD. The metal CBDs appeared to interact synergistically with the cellulases.