Every Protein identified?

[RMouse]

has every human protein been identified? Obviously you can't prove that something is there if you havent seen it, so I guess it is always possible that there are some proteins out there still waiting for discovery. But if it has been 5 or 10 years since a protein has been discovered, we can be sure that we are close to scraping the bottom.

Next, how many have been folded?

[Jesse_V]

No, to the best of my knowledge there are plenty of proteins that have yet to be discovered. Sure, plenty of them have been identified, but there are likely ones that have yet to be pursuited or discovered. By the way, you can be reasonably sure that a certain thing exists without seeing it. Also, some philosophers would argue against the idea of "proving" something just because you've trusted the principles and theories behind a tool to observe something that you can't see yourself. To them, only in math do you prove things, but that's a technicality here.

Who said it was 5 to 10 years since the last protein was discovered? I doubt that. Even if it was, that doesn't suggest that we're "scraping the bottom"; the remaining ones could be less interesting, more difficult to find, or simply have yet to be found.

Protein folding is not the only thing that needs to be done with proteins. There may also be a need to measure them, weigh them, figure out their structure, deform them, determine how they bind to other things, etc etc.

[bruce]

In that context, what is your definition of "identified"?

Does a protein have to be purified to be considered identified? Does it have to be crystallized and an image of the X-ray pattern recorded and the shape identified?

That's almost like asking if the genetic makeup of every individual, past present and future, been characterized to the point that there can be no more unique individuals.

[RMouse]

In that context, what is your definition of "identified"?

Does a protein have to be purified to be considered identified? Does it have to be crystallized and an image of the X-ray pattern recorded and the shape identified?

That's almost like asking if the genetic makeup of every individual, past present and future, been characterized to the point that there can be no more unique individuals.

Yes to the above questions. Certainly there are a finite number of proteins in the body and at some point we will know them all. I'm wondering how close we are to this point.

[PantherX]

Here is some interesting data that I found:

It is estimated that the human body may contain over two million proteins, coded for by only 20,000 - 25,000 genes. The total number found in terran biological organisms is likely to exceed ten million, but nobody knows for sure. Data is available on just over a million of them, taken mainly from information found in the over 100 genomes that have been fully sequenced.

Source -> http://www.wisegeek.org/how-many-proteins-exist.htm

[7im]

Not only is the total number unknown, some are just too large to model accurately with today's computers.

[RMouse]

Wow...I had no idea that there were so many unknown proteins. That's amazing............