Introduction to Enzyme and Coenzyme Chemistry - E-Library Home

Enzymatic Hydrolysis and Group Transfer Reactions 115
+
+
N
N
N
NH
CH 2 N
CH HN
NH HN
NH 2
NH
2 2
CH 2 HN
2
CH 2
H + N H
N
N
O N
N
O N
+
O
R
R
R
NH 2
N
H
HN
N
O N+
R
CH 2
:OH 2
N
NH 2
CH 2 OH
Figure 5.44 Methylene transfer to cytidine.
O
N
R
Thus, we have seen how enzymes are able to transfer a wide variety of
carbon- and phosphorus-base groups in biological systems. These reactions are
equally important for the breakdown and assembly of biological materials, and
form the cornerstone of the family of enzymatic reactions found in living
systems.
H
O
O −
ATP
ADP
H
O
OPO 2−
3
+
FH N
N
4 H
N
H
O
N
Figure 5.45 Biosynthesis of methyne-tetrahydrofolate.