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CASE FILES: BIOCHEMISTRY
ATP
ADP
OH
Phosphogluco-
oh
Hexokmase
mutase
Glucose 1-phosphate
G lu c o s e
Glucose 6-phosphate
UTP
UDP-glucose
pyrophosphorylase
UDP-glucose
U D P -g lu c o s e
dehydrogenase
2 NAD
2 NADH + 2H
C-O
Non
A
ok*—
r °
UDP
O H
UDP-glucuronate
UDP
UDP-glucuronosyl transferase
Acetaminophen
Acetaminophen glucuronide
Figure 40-1. Formation of UDP-glucuronate and acetaminophen glucuronide.
is the oxidation of the sixth carbon of glucose in UDP-glucose to the acid level
forming UDP-glucuronic acid. This reaction is catalyzed by UDP-glucose dehy-
drogenase, which also produces
2
mol of nicotinamide adenine dinucleotide
(NADH) as an additional product. UDP-glucuronyl transferase, in the next phase
of the reaction, catalyzes the transfer of the glucuronide group to the hydroxyl
group of acetaminophen forming acetaminophen glucuronide, which is elimi-
nated without toxic effects to the organism.
Alternatively, acetaminophen can be conjugated with organic sulfate for
elimination. This alternative pathway shown in Figure 40-2 also consists of
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