NATIVE, MODIFIED AND IMMOBILIZED CHYMOTRY PSIN IN SALTING-IN MEDIA LIMITS STABILIZATION

To stabilize alpha-chymotrypsin against irreversible thermal inactivat ion at high temperatures, methods of covalent modification and multi-p oint immobilization in combination with the addition of salting-in com pounds were used. The upper limit of the protein stability proved to b e the same for a combination of the modification and salting-in media and for each of these methods separately. The limit of stabilization r eached by means of covalent immobilization is higher than the limit of stabilization reached by two other methods. The greatest stabilizatio n of immobilized alpha-chymotrypsin by the salting-in media (a 10000 f old increase in the native enzyme's stability level) takes place only in the case of the protein with the minimum number of bonds with the s upport. Stabilization of the enzyme by these methods is explained in t erms of the suppression of the conformational inactivation processes.