Josive
Badges: 10
Rep:
?
#1
Report Thread starter 8 months ago
#1
Why does actin (Or all proteins for that matter) feel the need to change shape when things bind to them!
0
reply
HarisMalik98
Badges: 12
Rep:
?
#2
Report 8 months ago
#2
The final shape (conformation) of a protein is determined by the intramolecular interactions between the amino acid R-groups, hydrophobic interactions and covalent interactions.

In essence, the binding of a ligand alters the forces within the protein. An example could be: If a ligand binds to a certain 'hinge' domain on a protein which 'pulls' it out its natural position and exposes an usually-covered hydrophobic region. This now-exposed hydrophobic region can interact with other hydrophobic regions and cause the protein to change shape.

The binding of charged ligands can also alter the charge of nearby R-groups through electrostatic forces. If a certain R-group that is usually negative becomes positive, it may bind with a downstream negative R-group via an ionic bond. Or, the ligand may alter the charge at one end of the protein - altering its interactions with the opposite end.

I don't think you need to really worry about the detail of how it occurs, because I don't think scientists are completely sure on how it occurs either. Just know that ligand-binding alters the chemistry and bonding within the protein, which in turn alters its shape (conformational change). Whilst the ligand binding alters the chemistry and bonding of a protein, many proteins are "conformationally flexible" - meaning that removal of the ligand will allow the natural bonding to resume and the protein to return to its original shape. This flexibility between different states is what allows proteins to control biochemical pathways (e.g. ON or OFF).
Last edited by HarisMalik98; 8 months ago
0
reply
Josive
Badges: 10
Rep:
?
#3
Report Thread starter 8 months ago
#3
(Original post by HarisMalik98)
The final shape (conformation) of a protein is determined by the intramolecular interactions between the amino acid R-groups, hydrophobic interactions and covalent interactions.

In essence, the binding of a ligand alters the forces within the protein. An example could be: If a ligand binds to a certain 'hinge' domain on a protein which 'pulls' it out its natural position and exposes an usually-covered hydrophobic region. This now-exposed hydrophobic region can interact with other hydrophobic regions and cause the protein to change shape.

The binding of charged ligands can also alter the charge of nearby R-groups through electrostatic forces. If a certain R-group that is usually negative becomes positive, it may bind with a downstream negative R-group via an ionic bond. Or, the ligand may alter the charge at one end of the protein - altering its interactions with the opposite end.

I don't think you need to really worry about the detail of how it occurs, because I don't think scientists are completely sure on how it occurs either. Just know that ligand-binding alters the chemistry and bonding within the protein, which in turn alters its shape (conformational change). Whilst the ligand binding alters the chemistry and bonding of a protein, many proteins are "conformationally flexible" - meaning that removal of the ligand will allow the natural bonding to resume and the protein to return to its original shape. This flexibility between different states is what allows proteins to control biochemical pathways (e.g. ON or OFF).
Thanks so much really helped! So in laymans terms when a ligand bond's it can unlock certain 'blockages' in the protein allowing for chain reaction-like changes due to electro diffusion and concentration based diffusion? That sounds awesome
0
reply
HarisMalik98
Badges: 12
Rep:
?
#4
Report 8 months ago
#4
(Original post by Josive)
Thanks so much really helped! So in laymans terms when a ligand bond's it can unlock certain 'blockages' in the protein allowing for chain reaction-like changes due to electro diffusion and concentration based diffusion? That sounds awesome
No worries.

In laymans term i'd just simply say that ligand-binding alters the intramolecular bonding. This can occur in different ways, e.g: exposing/hiding certain regions of the protein, altering the charges at certain regions of the protein, or even binding to and bringing two regions of the protein closer together. Whatever the change may be, it ultimately changes the way the regions bind to each other and causes the protein to change shape.

Obviously the specific ligand interactions will be different for different proteins though.
Last edited by HarisMalik98; 8 months ago
0
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

Do you have the space and resources you need to succeed in home learning?

Yes I have everything I need (255)
56.92%
I don't have everything I need (193)
43.08%

Watched Threads

View All