Acetyl-CoA carboxylase 2 also known as ACC-beta or ACC2 is an
enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products ...
that in humans is encoded by the ''ACACB''
gene
In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...
.
Function
Acetyl-CoA carboxylase (ACC) is a complex multifunctional enzyme system. ACC is a
biotin-containing enzyme which catalyzes the
carboxylation
Carboxylation is a chemical reaction in which a carboxylic acid is produced by treating a substrate with carbon dioxide. The opposite reaction is decarboxylation. In chemistry, the term carbonation is sometimes used synonymously with carboxylatio ...
of
acetyl-CoA to
malonyl-CoA, the rate-limiting step in
fatty acid
In chemistry, particularly in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated. Most naturally occurring fatty acids have an unbranched chain of an even number of carbon atoms, ...
synthesis. ACC-beta is thought to control fatty acid oxidation by means of the ability of malonyl-CoA to inhibit
carnitine palmitoyltransferase I
Carnitine palmitoyltransferase I (CPT1) also known as carnitine acyltransferase I, CPTI, CAT1, CoA:carnitine acyl transferase (CCAT), or palmitoylCoA transferase I, is a mitochondrial enzyme responsible for the formation of acyl carnitines by c ...
, the rate-limiting step in fatty acid uptake and oxidation by
mitochondria. ACC-beta may be involved in the regulation of fatty acid oxidation, rather than fatty acid biosynthesis.
Clinical implications
Human acetyl-CoA carboxylase has recently become a target in the design of new anti-obesity drugs.
However, when the gene for ACC2 was
knocked out
A knockout (abbreviated to KO or K.O.) is a fight-ending, winning criterion in several full-contact combat sports, such as boxing, kickboxing, muay thai, mixed martial arts, karate, some forms of taekwondo and other sports involving strikin ...
in mice, no change in body weight was observed relative to normal mice.
This result suggests inhibition of ACC2 by drugs may be an ineffective method of treating obesity.
References
Further reading
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External links
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EC 6.4.1
Human proteins
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