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Arylamine
N-acetyltransferases. Part 2
I'm Edith Sim and I've been
working on these enzymes
for over 20 years.
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So human NAT1 is a phase II
drug-metabolizing enzyme.
It's over 80% identical
to human NAT2.
It's widespread
tissue distribution.
It is also subject
to genetic polymorphism.
And the genetic polymorphism,
like in human NAT2,
appears in many instances
and result in the protein
being degraded within cells,
therefore, being unavailable
to carrier deacetylation.
Human NAT1 has got a different
substrate specificity
then human NAT2.
It N-acetylates,
para-aminobenzoic acid
and para-aminosalicylate.
It's expressed
early in development,
unlike human NAT2.
It is overexpressed
in ER positive breast cancer.
And recently it's also been
demonstrated that
it hydrolyses acetylCoA
in the presence of folate.
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The evolution of a tree
of NATs in primates,
although all of these enzymes
are very similar,
clearly divides
into three groups.
The NAT1s, the NAT2s,
and the NAT pseudo genes.
Therefore, this suggests
that the duplication
of these loci occurred
prior to the break time
or the development
of the different strands
of the primate derivatives.