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PHOTOREGULATION OF α‐CHYMOTRYPSIN ACTIVITY IN ORGANIC MEDIA: EFFECTS OF BIOIMPRINTING
Author(s) -
Willner Itamar,
LionDagan Mazzi,
Rubin Shai,
Wonner Johann,
Effenberger Franz,
Bäuerle Peter
Publication year - 1994
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1994.tb05070.x
Subject(s) - chymotrypsin , chemistry , photoisomerization , cyclohexane , stereochemistry , phenylalanine , substrate (aquarium) , enzyme , organic chemistry , trypsin , biochemistry , amino acid , catalysis , isomerization , biology , ecology
α‐Chymotrypsin exhibits photoswitchable activities in an organic solvent after covalent modification of the protein backbone with thiophenefulgide active ester (2). The thiophenefulgide‐modified α‐chymotrypsin exhibits reversible photoisomerizable properties between states (3)‐E and (3)‐C. The modified α‐chymotrypsin, where nine lysine residues are substituted by thiophenefulgide units, retains 60% of the activity of the native enzyme. The activities of thiophenefulgide‐modified α‐chymotrypsin toward esterification of N ‐acetyl‐L‐phenylalanine (4) by ethanol in cyclohexane are controlled by the configuration of the attached photoisomerizable component and by prior bioimprinting of the protein backbone with the reaction substrate (4). The esterification of (4) in cyclohexane using bioimprinted (3)‐C is two‐fold faster than in the presence of (3)‐E. In the presence of a nonbioimprinted enzyme, esterification of (4) by (3)‐C is five‐fold faster than with (3)‐E. The activity of bioimprinted (3)‐E toward esterification of (4) is 4.5‐fold higher than that of nonbioimprinted (3)‐E. Switchable cyclic esterification of (4) is accomplished by sequential photoisomerization of the thiophenefulgide‐modified α‐chymotrypsin between states (3)‐C and (3)‐E.