Sulfotransferases Flashcards
What is sulfation?
An important route of metabolism for many xenobiotics and endogenous compounds
What are examples of xenobiotics and endogenous compounds associated with sulfation?
Steroid and thyroid hormones, neurotransmitters, drugs, diet constituents and environmental chemicals
Sulfation is a key step in the __________ of many chemical carcinogens
bioactivation
What catalyzes sulfation*?
Members of the cystolic SULT (sulfotransferase) family
What are the main functional groups sulfated?
Hydroxyl and amine
What is the main site of sulfation?
Liver
What are the four different families of the 13 functional SULT proteins in humans?
SULT1 (8), SULT2 (3), SULT4 (1), SULT6 (1)
What is the protein that is encoded by the SULT1A3 and SULT1A4 gene sequences?
SULT1A3/4
How does SULT2B1 produce two distinct enzymes from the same gene?
By using two different 1st exons
Is SULT4A1 a sulfotransferase enzyme? Why or why not?
It is most likely not a sulfotransferase enzyme as it does not bind PAPS. It is very highly conserved between species and is found exclusively in the brain
What does Minoxidil do?
It is an over-the-counter drug that also comes topical liquid/foam used to treat male pattern baldness since SULT1A1 is expressed in the roots and sulfate agent activates hair growth
People with _____ SULT1A1 do not respond well to minoxidil
low
What is another use of Minoxidil besides treating baldness?
Lowers blood pressure
What are the similarities/differences between SULT1A1 and SULT1A3?
The two SULTs only differ by 20/295 amino acids (93% identity) but their substrate preferences are markedly different
What is the function of the α-6 Helix?
Covers the active site in the SULT1A3 and SULT1A1 amino acids
