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Studies on the inhibition of the desaturases by cyclopropenoid fatty acids
Author(s) -
Jeffcoat R.,
Pollard M. R.
Publication year - 1977
Publication title -
lipids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.601
H-Index - 120
eISSN - 1558-9307
pISSN - 0024-4201
DOI - 10.1007/bf02535446
Subject(s) - biochemistry , enzyme , coenzyme a , microsome , chemistry , cofactor , fatty acid , clinical chemistry , covalent bond , stereochemistry , organic chemistry , reductase
Unwashed rat liver microsomes were used to study the inhibition of the Δ 6 and Δ 9 desaturases by cyclopropenoid fatty acids with the ring structure about the 9,10 or 6,7 carbon atoms. The 9,10 cyclopropenoid acid (sterculic acid) is shown to be an effective inhibitor of only Δ 9 desaturase and then only in the presence of MgCl 2 and coenzyme A (prepresence of MgCl 2 and coenzyme A (presumably due to the formation of sterculoyl‐CoA). Two 6,7 cyclopropenoid acids of different chain lengths showed no marked inhibition of either the Δ 6 or Δ 9 desaturase. By the use of [ 3 H]‐sterculic acid, it has been shown that under conditions of high inhibition of the Δ 9 desaturase the inhibitor is not covalently attached to the enzyme at any point. This disproves older ideas on the mechanism of inhibition that assumed reaction between the cyclopropenoid ring and sulphydryl groups on the enzymes.