Desorption of CBH1 from BMCC substrate was studied here as a function of enzymatic activity.  CBH1 was first separated from Spezyme CP cellulases by ion exchange chromatography.  The maximum adsorption capacity of CBH1 was about 4 μmol/g BMCC.  No desorption of CBH1 was detected following 1-hour incubation after dilution at 0 oC (in an ice-water bath).  At an enzyme loading of 2.1 μmol/g BMCC, almost all CBH1 adsorbed onto the substrate.  The CBH1 and BMCC were incubated together for two days.  Free enzyme in the solution was monitored during this period.  The CBH1 showed different desorption behavior depending on enzymatic activity.  Desorption was quantified by measuring CBH1 content in the buffer solution using the Bradford Assay.  About 30% desorption of CBH1 was observed at 0 oC (with end-over-end mixing); nearly 100% desorption of CBH1 occurred at 50 oC and 150 rpm on a shaker table; 35% desorption of CBH1 occurred at 50 oC and 300 rpm (enzymatic activity was lower than at 150 rpm). With the addition of K2PdCl6, which denatured the catalytic domain of the CBH1, desorption decreased from ~100% to ~40% after a two-day incubation period at 50 oC and 150 rpm.  PNPC assay was used in each of these cases as a means to determine enzymatic activity.  The amount of CBH1 desorption was seen to decrease as a function of decreasing enzymatic activity, whether the reduced activity was due to the denaturing agent, low incubation temperature, or difference in the shear environment.