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Purification, Properties, and Specificity of Rat Brain Cytosolic Fatty Acyl Coenzyme A Hydrolase
Author(s) -
Broustas Constantinos G.,
Hajra Amiya K.
Publication year - 1995
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1046/j.1471-4159.1995.64052345.x
Subject(s) - cytosol , biochemistry , coenzyme a , acyl coa , chemistry , cofactor , hydrolase , enzyme , biology , reductase
Rat brain cytosolic acyl‐CoA hydrolase has been purified 3,500‐fold to apparent homogeneity using heat treatment, ammonium sulfate fractionation followed by anion exchange, hydrophobic interaction, and hydroxyapatite chromatography. The purified enzyme remains stable only in the presence of a high concentration (30%, vol/vol) of ethylene glycol. On sodium dodecyl sulfate‐polyacrylamide gel electrophoresis the purified enzyme shows a single band of 40.9 kDa. However, on high‐performance size‐exclusion chromatography the migration rate of the enzyme corresponds with an apparent molecular mass of 148 kDa, indicating that the native enzyme may be a tetramer. The enzyme catalyzes the hydrolysis of fatty acyl‐CoAs from six to 18 carbon chains long, having the highest activity for lauroyl (12:0)‐CoA. For the purified enzyme the K m for palmitoyl‐CoA is 5.8 µ M and the V max is 1,300 µmol/min/mg of protein. The enzyme is inhibited by bovine serum albumin, various detergents, lysophosphatidylcholine, and palmitoyl carnitine. Among the sulfhydryl agents, only p ‐hydroxymercuribenzoate inhibited the enzyme. The enzyme is also inactivated by treatment with a high concentration of diethyl pyrocarbonate, an active center histidine‐reacting agent, but not by phenylmethylsulfonyl fluoride (10 m M ), a serine esterase inhibitor. The purified enzyme does not appear to possess any O ‐ester hydrolase, lysophospholipase, transacylase, or acyltransferase activity.