Naked Science Forum

Life Sciences => Cells, Microbes & Viruses => Topic started by: thedoc on 13/12/2016 18:53:05

Title: How do the proteins not become this giant mess of tangled threads?
Post by: thedoc on 13/12/2016 18:53:05

Priyadarshini Chatterjee asked the Naked Scientists:
   
Hi! I've recently stumbled across this amazing website!

I was wondering how proteins in the cells just after translation at the ribosome do not get tangled up with each other. There are so many different proteins and they are huge strings of amino acids and the cell is a tiny little structure, how do the proteins not become this giant mess of tangled threads?

What do you think?

Title: Re: How do the proteins not become this giant mess of tangled threads?
Post by: evan_au on 14/12/2016 15:34:30

Proteins tend to adopt the configuration of lowest energy, in their environment inside a cell.
- They have regions that are more positive, which attract regions that are more negative.
- They have regions which are more water-repellant, which tend to clump together away from  the surrounding water.
- They are often assembled from smaller components
- They have proteins and enzymes that modify them and help assemble them.

See: https://en.wikipedia.org/wiki/Protein_folding

This process is so complex that there is a citizen-science "game" where members of the public work out how to fold proteins. Apparently, some people are much better at this than computers!
See: http://fold.it/portal/info/science

Title: Re: How do the proteins not become this giant mess of tangled threads?
Post by: MayoFlyFarmer on 11/04/2017 15:27:46

Two factors that the original question failed to consider:

1) proteins fold AS they are being translated rather than waiting for translation to finish and then folding all at once.  Therefore, you don't have all these long strings of amino acids just hanging around.

2) While cells are very small and compact, proteins are even smaller, so they have a reasonable amount of room in which to translate and fold.