Enhanced in vivo catalytic activity of PEG-modified cellulase complex from Trichoderma reesei

The cellulase complex from Trichoderma reesei was polyethylene glycol (PEG)-modified with considerable retention of endo-beta-1,4-glucanase activity, as evaluated by the carboxymethylcellulase (CMCase) assay. While resistance towards heat denaturation was the same for either form, susceptibility towards proteolysis was slightly greater for the PEG-conjugate, in contrast to most reports using other enzymes. The circulatory life of endoglucanase activity associated with the complex was enhanced upon PEG-modification. This was confirmed by demonstrating degradation of chromogen-labelled substrate injected (i.v.) after 24hr of administration of the PEG-ylated enzymes; in contrast the substrate remained undegraded in mice pretreated with the native complex. The PEG-modified complex could be a good candidate for the treatment of pneumoconioses of textile workers exposed to cotton dust.