16
Bioorganic Chemistry
N
N
N
H
O
Pyrrole/pyrrole pair soley donates
hydrogen bonds to minor groove floor
and therefore recognizes soley hydrogen
bond accepting AT or TA base pairs
Imidazole/pyrrole pair both
donates to and accepts hydrogen
bonds from minor groove floor and
therefore recognizes GC base pairs.
N
N
H
N
N
H
N
N
O
O
H
O
O
O
N
N
H
N
H
N
N
N
H
O
N
N
H
O
O
N
H
N
H
N
N
N
O
O
H
N
H
N
N
N
N
H
• •
• •
• •
N
N
N
N
N
H
O
H
N
N
N
O
H
• •
H
• •
H
T
A
G
C
O
N
Fig. 12
Details of the mechanism of differentiation of AT and GC base pairs by ‘‘side-by-side’’
hairpin polyamides.
ring nitrogen) has the ability to accept
a hydrogen bond. Oligomers built using
these ‘‘pairing rules’’ of oligomer sequence
matched with DNA sequence have shown
remarkable afFnity and speciFcity for se-
quences of DNA and may have application
as in diagnostics and therapeutics.
4
Protein Studies
4.1
Enzyme Inhibition
The study of enzyme inhibition is a major
focus of bioorganic chemistry for two
major reasons. ±irstly, enzyme inhibitors
are useful tools for understanding enzyme
structure and mechanism of action. Sec-
ondly, enzyme inhibition has proven to
be a successful strategy for the design of
therapeutics. Examples of drugs that act
by inhibiting enzymes include methotrex-
ate, Deprenyl, and Enalapril. Inhibitors can
block enzyme function by preventing ac-
cess of the natural substrate to the active
site or by stopping the subsequent reac-
tion from taking place by, for example,
chemically blocking a key catalytic group
on the enzyme.
There are two broad classes of in-
hibitors, covalent and noncovalent, the
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