Amino
Acids on Earth
by
Rebecca Burke
1.
The properties of Arginine are:
-
Hydrophillic, polar
-
Basic
-
ionizable R group
-
at neutral pH positively charged
-
interacts with negatively charged
species via hydrogen bonding
-
functional group containing
N
-
Can be found in the active sites
of enzymes
-
contains a naturally occurring
internal shift base
2.
A derivative of Arginine would be:
3.
An interesting biological or pharmaceutical role of this arginine derivative
is:
-
ADP-ribosylation of arginine
occurs in cell surface proteins for regulatory purposes. ADP-ribosylation
inactivates arginine, thereby preventing the activation of cell surface
proteins and subsequent downstream cellular signal transduction mechanisms.
4.
On a biosphere on a distant planet outside our solar system, a different
but related amino acid is found:
-
On planet Telenium, the amine
group in arginine is replaced by hydrogen. On this planet enzymes
are not bound as tightly to their substrates because this modification
results in the reduction of hydrogen bonding capabilities. It serves
a structural function similar to lysine or arginine.
