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Prostaglandin H synthase
Author(s) -
Mevkh Alevtina T.,
Miroshnikov Konstantin A.,
Igumnova Natalia D.,
Varfolomeev Sergey D.
Publication year - 1993
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(93)80109-8
Subject(s) - chemistry , histidine , cleavage (geology) , enzyme , chemical modification , prostaglandin , stereochemistry , atp synthase , biochemistry , substrate (aquarium) , catalysis , biology , paleontology , ecology , fracture (geology)
Prostaglandin H synthase (PGHS) as apo‐PGHS, holo‐PGHS, and holo‐PGHS, inactivated in the course of catalysis was studied using chemical modification with diethyl pyrocarbonate (DEPC). The exhausted reaction with DEPC corresponded to the modification of 7 histidine residues in apo‐PGHS and 4 in holo‐PGHS. All 18 histidine residues became accessible for modification with DEPC in the enzyme, inactivated in the course of catalysis. The velocities of tryptic cleavage of all the three forms into two fragments were fairly different but independent of modification. Based on the results we hypothesize fast and dramatic changes in the protein structure in the course of the substrate conversion.