This research was to prove whether there is some special protein in cellulaseproducing microorganism acting as a cellulaseactivityenhancing protein,thus exploring its potential application in lignocellulose hydrolysis.An extracellular protein without cellulase activity was separated and purified from culture medium of Trichoderma Koningii through a series of procedures
including ultrafiltration
ammonium sulfate precipitation
octylSepharose CL4B and Sephadex G75 column chromatographyThe molecular weight of the prtotein was estimated to be 30×103 by SDS-PAGEWith the addition of this protein(400μg per g filter paper)into the reaction mixture containing filter paper and cellulase(0.06 IU per g filter paper )
the reducing sugar released during 48 h was observed to increase greatly
1049% greater than that of the control hydrolysisMoreover
it was found that this purified protein enhanced the activity of exoglucanase
one of the three components of fungi cellulase
while endoglucanase and β-glucosidase activities did not change muchMass spectrometry analysis indicated that this purified protein was an unknown proteinBased on these results
this purified extracellular protein originated from Trichoderma Koningii could be regarded as a cellulase activityenhancing protein
which was different from the reported plant expansin and swollenin.