A 37-year-old 32-week pregnant woman is brought to the emergency room after suffering several seizures. Additional symptoms found in this patient are swollen hands and feet, blood pressure 165/125, right quadrant belly pain, and significant proteinuria. The ER physician suspects the woman is suffering from preeclampsia. Additional blood work indicates a deficiency in zinc. Which of the following amino acids serves as substrate for an important enzyme whose activity is impaired by a deficiency in zinc and could therefore explain the signs and symptoms in this patient?

Question

Quizplus · Accepted Answer

The glutamate derivative, g-aminobutyrate (GABA; also called 4-aminobutyrate) is a major inhibitor of presynaptic transmission in the CNS. Glutamic acid decarboxylase (GAD) catalyzes the decarboxylation of glutamic acid to form GABA. The activity of GAD requires pyridoxal phosphate (PLP) as a cofactor. PLP is generated through the action of pyridoxal kinase. Pyridoxal kinase itself requires zinc for activation. A deficiency in zinc or defects in pyridoxal kinase can lead to seizure disorders, particularly as seen in this preeclamptic patient.

A 37-Year-Old 32-Week Pregnant Woman Is Brought to the Emergency