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Annexin‐I inhibits phospholipase A 2 by specific interaction, not by substrate depletion
Author(s) -
Kim Kyoung Mi,
Kirn Dai Kyung,
Park Young Min,
Kim Chong-Kook,
Na Doe Sun
Publication year - 1994
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(94)80566-0
Subject(s) - substrate (aquarium) , annexin , chemistry , substrate specificity , phospholipase , biophysics , biochemistry , enzyme , biology , cell , ecology
Annexin‐I is a calcium dependent phospholipid binding and phospholipase A 2 (PLA 2 ) inhibitory protein. A ‘substrate depletion’ model has been proposed for the mechanism of PLA 2 inhibition by annexin‐I in studies with 14 to 18 kDa PLA 2 s. Herein, we have studied the inhibition mechanism using 100 kDa cytosolic PLA 2 from porcine spleen. The inhibition has been measured at various substrate and calcium ion concentrations. The pattern of PLA 2 inhibition by annexin‐I was consistent with a ‘specific interaction’ mechanism rather than the ‘substrate depletion’ model. Apparent contradiction with previous studies can be explained by the calcium‐dependent binding of annexin‐I to the substrate.