Transcript diabete gene

Diabetes
Revision of protein structure and
the importance of genetic
engineering in the control of
diabetes
Some diabetes sufferers control their blood
glucose levels by regular insulin
injections.
This means that they must test for blood
glucose levels on a regular basis.
The injection must be taken 30 mins
before a meal twice daily.
Insulin is a hormone. It is made of protein
and is involved in the regulation of
glucose levels in the blood
The primary
sequence
Notice amino acids are
represented by three letters
lower case.
The secondary structure. The
alpha and beta chains chain
contains helical forms.
This is caused by hydrogen
bonding between R groups on
the amino acids.
The tertiary structure causes the
formation of a monomer.
The quaternary structure involves the interaction
of monomers to form hexamers.
Ribbon model of the hexamer unit
Insulin is injected as a
hexamer as the
monomers only exist at
low concentrations
making the volume to
large to be injected
The insulin is released as a hexamer, which must be broken down to
form monomers.
Injected insulin is in the form of hexamers and it takes half an hour for
the hexamers to form monomers and get into the blood stream. The dose
contains two forms of insulin one a slow release and one a fast release
form.
Hexamers have to be injected as they exist in only very low
concentrations. They naturally form hexamers at high concentrations. To
inject the monomers at a low enough concentration at the right amount
would involve too larger a volume
Can genetic engineering come the
the rescue?
Producing insulin by genetic engineering
Modifying the amino acid sequence could
stop the hexamers from forming by altering
the intermolecular forces of attraction to
prevent clumping
Using computer modelling and computer
graphics, it has been found that swapping
the beta chain 9th amino acid (ser) with asp
stops the clumping
How can we change one residue?
Consideration of insulin has allowed us to
revise structure of proteins and see how
genetic engineering has been used to modify
a protein to enhance its performance in a
medical context.