Factors affecting the activity of immobilized enzymes, I. Diffusional limitation.

The measured (apparent) specific activities of immobilized lactate dehydrogenase, malate dehydrogenase, glucose dehydrogenase, alkaline phosphatase and chymotrypsin decrease with increasing activity loading and increase with decreasing particle diameter and with increasing substrate concentration. The observed inactivation is therefore concluded to be due to diffusional limitation. Real specific activities are not greatly affected by the immobilization, as has been demonstrated after enzymic digestion of the matrix. In the case of lactate dehydrogenase and of malate dehydrogenase real specific activities are not altered by a variation of the number of bonds to the carrier.