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Catalog #
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DMG-3A5-200
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Size
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200 Reactions
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Store At
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-20°C
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Human Cytochrome P450 3A5 (CYP3A5) is a member
of the monooxygenase superfamily of enzymes involved in the
synthesis of cholesterol, steroids, and other lipids. CYP3A5 is found
in the liver but is primarily an extrahepatic enzyme associated with the
lungs, colon, kidney, esophagus, and anterior pituitary1. It is one of
four highly homologous proteins known as niphedipine oxidases within
the CYP3A subfamily2. CYP3A5 shows 83% homology to CYP3A4
and metabolizes many of CYP3A4’s substrates but at lower turnover
rates1, 3. The CYP3 family is involved in xenobiotic and endogenous
steroid metabolism and contributes to first-pass drug metabolism4. The
CYP3A subfamily of enzymes is involved in the metabolism of about
50% of currently prescribed drugs5. Among the various substrates of
CYP3A5 are therapeutic drugs such as the antihypertsive nifedipine,
the cholesterol-lowering lovastatin, the sedative-hypnotic triazolam,
and the antineoplastic vincristine. Some chemicals can influence the
activity of this enzyme. For example, phenobarbital and rifampin will
induce CYP3A5, while ketoconazole will inhibit the enzyme1. The
CYP3A5 gene is genetically polymorphic among individuals and ethnic
groups. Some of the known single nucleotide polymorphisms
(SNPs) in CYP3A5 can cause alternative splicing and protein truncation,
which leads to an absence of the enzyme in some individuals.
Caucasians show a higher frequency of these SNPs than African Americans
6. If CYP3A5 is expressed, it makes up 50% of the total CYP3A
content in the liver7. The gene is located on the complementary strand
of chromosome 7q21 and spans approximately 31 kb with 16 exons.
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