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Identification and characterisation of substrate requirements for brain long chain fatty acyl CoA synthase (LCAFCoAS) isoforms
Author(s) -
Pillai Venkateswaran C.,
Bazinet Richard P.,
Rapoport Stanley I.,
Weis Margaret T.
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.5.a607-a
Subject(s) - gene isoform , substrate (aquarium) , fatty acid , linoleic acid , palmitic acid , biochemistry , chemistry , stereochemistry , biology , gene , ecology
LCFACoAS activates fatty acids to their acyl CoA derivatives, a necessary step for fatty acid utilization. We isolated two LCFACoAS isoforms (BP1 and BP2) from rat brain and identified substrate preferences with respect to cis/trans configuration and chain length. Activity was measured using 12 μM [ 14 C]palmitic acid as substrate. Unlabeled competitor fatty acids were added at concentrations ranging from 0.8μM to 1.2 mM. The EC 50 was determined from pseudo‐Hill plots, and is presented in the table. The rank order of substrate preference was different for the two isoforms, with linoleate being the most preferred for BP1 and palmitelaidate the most preferred for BP2. Pseudo‐Hill plot slopes were significantly greater than ‐1 for the saturated fatty acids and linoleic acid, but not different from ‐1 for the other unsaturated fatty acids. The data support our hypothesis that the two isoforms have slightly different reaction mechanisms, a difference that can be exploited to produce isoform‐specific inhibitors. Supported by AHA 61A06552254.