selenium proteins

What is selenoprotein P?

The major transport protein for selenium in the blood.

What are the functions of selenoprotein P?

Transports selenium, stores selenium, and functions as an antioxidant.

What percentage of plasma selenium is carried by selenoprotein P?

About 50–80%.

What is glutathione peroxidase (GPx)?

A selenium-dependent antioxidant enzyme.

What is the function of glutathione peroxidase?

Reduces peroxides and protects cells from oxidative damage.

What does glutathione peroxidase protect?

Cell membranes from oxidative damage.

What is thioredoxin reductase?

A selenium-dependent antioxidant enzyme.

What is the function of thioredoxin reductase?

Reduces oxidized thioredoxin and maintains cellular redox balance.

What is iodothyronine 5'-deiodinase?

A selenium-dependent enzyme that converts T4 to T3.

What is the function of iodothyronine 5'-deiodinase?

Converts inactive T4 into active T3.

Why is iodothyronine 5'-deiodinase important?

T3 is the active thyroid hormone.

What happens to thyroid hormones during selenium deficiency?

T3 decreases and T4 increases because less T4 is converted to T3.