Sciencemadness Discussion Board

How fast does body build long protein

Random - 7-2-2016 at 12:17

Hoe fast does body build one unit of a protein that is 100000 amino acids long? It seems that because of structure that is not just a simple chain for example of random molecules like cellulose glucose polymer, is there a time that needs to pass?

Metacelsus - 7-2-2016 at 13:08

The largest known protein (titin) has "only" ~33,000 residues.
https://en.wikipedia.org/wiki/Titin

Ribosomes can polymerize around 20 amino acids per second in prokaryotes and around 8 per second in eukaryotes.
https://en.wikipedia.org/wiki/Translation_%28biology%29

phlogiston - 7-2-2016 at 13:36

I once attended a very interesting lecture by someone who elucidated how ribosomes sometimes pause during the synthesis of a protein to allow it time to fold properly.
The duration of the pause and generally the speed at which ribosomes operate is dictated by the codons used (most amino acids can be encoded by several different codons) and it turns out that in some cases this is critical for the resulting protein to achieve its proper configuration.

[Edited on 8-2-2016 by phlogiston]

Random - 9-2-2016 at 04:34

Interesting stuff guys thanks. It means also that titin takes about half an hour to synthesize!

I guess its needed for muscle hypertrophy? So the hypertrophy is hapenning somewhat slowly compared to some other changes. It's interesting how the science between muscle hypertrophy is still somewhat unknown. But this is getting offtopic now.

Tsjerk - 9-2-2016 at 04:56

I don't think you can correlate the length of a protein, and thus the speed at which a single ribosome can synthesize it, to the speed at which muscles grow.

A cell contains (lets say) one thousand ribosomes. If the cell would for example employ half of those to form titin, the size of the protein does not correlate to the total mass of formed protein anymore (500 proteins in half an hour).

You could compare this with 500 ribosomes synthesizing 5.000 proteins that are 1/10 the size of titin. The total mass of protein will be the same in the end.

I think the limiting factors in hypertrophy are for example the amount of amino acids available, the other components in the muscle that the muscle needs to grow (physical number of cells, cellular skeleton to bind all these proteins to etc.).

Most important though; is it beneficial for the organism to have faster muscle growth than we see now? Do you want to gain 10 kilos in a month of hard labor and unlimited nutrients? 100.000 years ago you would die with that amount of muscle to maintain if you have no nutrients the next three months (winter).

gregxy - 9-2-2016 at 11:06

Body builders like to drink a protein shake immediately after their workout.
The idea is that the exercise increase the uptake of amino acids into the muscle cells. That way the protien is used to rebuild the cells and muscle instead of being converted to fat in the liver. (exercise increase the insulin sensitivity of the cells or they are simply hungry after burning their stored energy)

There is also a protein/hormone that controls the atrophy of muscle myostatin. The have bred cows where it is "knocked out". The results are really spectacular.
www.reddit.com/r/pics/comments/1gupnu/a_cow_born_without_the...

Tsjerk - 9-2-2016 at 13:09

I did some ''body building'' in the past, and I don't believe it really makes a difference whether you drink your protein shake just after, before or during your work-out. Just make sure you get as shit load of slow carbs and proteins spread over the day and you will be fine... or do I now sound like a pseudo-scientist?

Doing a attempt to get the tread back on topic again; the human body is very capable of maintaining itself and regulating itself. It stores everything it needs as long as it thinks it needs it. If the body thinks it should do something at a certain speed, it will do it at that speed. If the cell thinks titin has to be produced at speed x it will have x ribosomes producing it.

Everything is either controlled and or regulated by pathways we do or don't understand. We can influence with steroids, drugs and or metabolites. but please don't. Just eat and train.

phlogiston - 9-2-2016 at 14:02

Yes, Tsjerk makes a good point there. The body makes muscle when it decides it needs it, and an excellent way to convince your body it needs more muscle is too push the existing muscles to their limit. In other words, exercise.
This will trigger whatever natural pathways exist to prepare the body better for the next challenge, ie make more muscle.

Consuming protein shakes or other sources of amino acids will not do much for this purpose, except replenish amino acids if they are needed. However, the body can synthesize the majority of amino acids when it needs them. There are only a few essential amino acids and you would have to have a pretty odd diet for your body to run out of those (admittedly, many body builders do have odd diets).
If extra amino acids are not needed they are burned as fuel. Some amino acids (the branched chain amino acids) are released when muscles are damaged so, conceivably, they could be one of the myriad of signals that tell the body it needs more muscle but it is hardly a specific one and certainly not enough to do anything for your muscles all by itself.

[Edited on 9-2-2016 by phlogiston]

mayko - 9-2-2016 at 14:51

Quote: Originally posted by phlogiston  
I once attended a very interesting lecture by someone who elucidated how ribosomes sometimes pause during the synthesis of a protein to allow it time to fold properly.
The duration of the pause and generally the speed at which ribosomes operate is dictated by the codons used (most amino acids can be encoded by several different codons) and it turns out that in some cases this is critical for the resulting protein to achieve its proper configuration.

[Edited on 8-2-2016 by phlogiston]


Here's some more on that (very interesting!) phenomenon:
Quote:

As an approach to investigate the molecular mechanism of in vivo protein folding and the role of translation kinetics on specific folding pathways, we made codon substitutions in the EgFABP1 (Echinococcus granulosus fatty acid binding protein1) gene that replaced five minor codons with their synonymous major ones. The altered region corresponds to a turn between two short alpha helices. One of the silent mutations of EgFABP1 markedly decreased the solubility of the protein when expressed in Escherichia coli. Expression of this protein also caused strong activation of a reporter gene designed to detect misfolded proteins, suggesting that the turn region seems to have special translation kinetic requirements that ensure proper folding of the protein. Our results highlight the importance of codon usage in the in vivo protein folding.


Cortazzo, P., Cerveñansky, C., Marín, M., Reiss, C., Ehrlich, R., & Deana, A. (2002). Silent mutations affect in vivo protein folding in Escherichia coli. Biochemical and Biophysical Research Communications, 293(1), 537–41. doi:10.1016/S0006-291X(02)00226-7



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