The Effect of Temperature on the Chromatography of Insulin on Deae-Cellulose

Abstract

The effect of ionic strength (range 0,15-0, 3), pH (range 7-9), and temperature (range I-25°C) on the chromatographic behaviour of three samples of insulin on diethylaminoethyl (DEAE)-cellulose columns has been studied. These three factors have a similar effect, a decrease of temperature or pH and an increase in ionic strength lowering the elution volume of the protein. The marked effect of temperature is not due to aggregation-disaggregation of the insulin since bovine plasma albumin which does not aggregate reversibly also showed this effect. The desamido component of insulin could not be detected in commercial insulin under the conditions studied but a minor component varying from 2-6 per cent. of the insulin was separated, as well as various amounts of bound ammonia. Removal of zinc from the insulin did not affect the elution curve.