Principles of enzyme stabilization. V. the possibility of enzyme selfstabilization under the action of potentially reversible intramolecular cross-linkages of different length
Torchilin, V.P.; Maksimenko, A.V.; Smirnov, V.N.; Berezin, I.V.; Martinek, K.
Biochimica et Biophysica Acta 568(1): 1-10
ISSN/ISBN: 0006-3002 PMID: 444535 DOI: 10.1016/0005-2744(79)90267-5
The denaturing action of guanidine . HCl on modified alpha-chymotrypsin (EC 126.96.36.199) preparations has been studied. The consecutive treatment of alpha-chymotrypsin with N-acetyl-homocysteine thiolactone, 5,5'-dithio-bis-(2-nitrobenzoic acid) and dithiols of HS-(CH2)n-SH type, with n ranging from 4 to 10, leads to enzyme stabilization as a result of protein modification. A greater stabilization effect can be achieved by enriching the protein molecule with groups reactive towards dithiols, after first modifying carboxygroups. In this case dithiol with n=5 forms an intramolecular cross-linkage. If an equimolecular mixture of different dithiols is used for enzyme modification, the enzyme gradually 'selects' 1,5-dithiol for the formation of an intramolecular cross-linkage instead of the initial one-point modification. The use of potentially reversible cross-linkages may be generally employed for the preparation of stabilized water-soluble enzymes via the mechanism of selfstabilization.