How are amino acids connected in a lab?

Question

I want to do a little science experiment and make my own complex molecules at home. Amino acids are readily available as vitamin supplements (all 20 of them). What I need to know is what chemicals to use to make chains with them. Any help is greatly appreciated.

Also, if you didn't know, all amino acids have a carboxylic acid group and a primary amine group, if this helps with an answer.

Answer 1

the subject of protein synthesis is very extensive to dicuss in this forum. There are many chemicals used, like boc and fmoc, Sanger's reagent, etc. So, I strongly suggest reading any good biochem book or online resource.

In any case, general method of synthesis requires the following general, non-exclusive steps. Bind the starting or chosen "left end amino acid" to a particular inert substrate. This leaves the other part of the amino acid to react. Then "deactivate' with a number of chemicals reagents, the N terminal of the amino acid. After the formation of the peptide bonds, the peptide is treated with another set of chemicals like TFA(triflouroacetic acid) to remove the "deactivators".

It is worth mentioning that the synthesis is pH dependent. Also check in what form ( as chloride, tartrate, succinate, etc) the amino acids are in your vitamin bottle.

Answer 2

I'll jump in here just because the answers you've been given sound too scientific and not very practical.

Practically, if you want to make a controlled chain of amino-acids, by which I mean one where you control the sequence, there is absolutely no way to do that using amino acids from vitamin supplements.

The way chemists make such chains is by protecting one end (amines and carboxylic acids react with one another, so if you want to control the reaction, one end has to be "hidden") using protecting groups such as "Fmoc" and "Boc." That way you can add one amino acid at a time and make a chain with a known sequence. In addition, the amino acids will not react by themselves, so you need an activating group (things with names like "HBTU" and "HOBt"). Unfortunately, you pretty much have to have access to a chemistry lab with the right equipment to do this. You can read about the process here: http://en.wikipedia.org/wiki/Solid_phase_peptide_synthesis#Solid-phase_synthesis

In theory, you could make random peptide chains by heating amino acids in solid form together at ~200 degrees celsius (~450 fahrenheit, one of the highest temprature settings in most ovens). Unfortunately, most amino acids will actually decompose at that temperature.

Personally, I would recommend some alternative experiments. For example, if you want to grow things, you can take a few cups (I recommend glass or tough plastic), fill them with water, and then add a few drops of different liquids, such as milk (high pH), orange juice (low pH), sugar, salt (high ionic strength), a crushed-up blade of grass, etc. to them. Let them sit for a few days, and you will probably notice that rather different things happen to them. You are getting pretty different communities. If your school has a science lab with a microscope, you can take a drop or two and look at the various communities--very different things will be growing in them.

As a chemist, I really appreciate your enthusiasm. On the other hand, making peptides and proteins at home is essentially impossible. However, if there is a college or university where you live, realize that you can probably apply to do some research in a lab. Some places would even pay you. I would recommend looking at the websites of relevant universities/colleges, looking at the webpages for chemistry, biochemistry, or biology departments, and then sending a polite e-mail to a few of the faculty telling them that you are interested in science and biomolecules, and asking if you could work in their lab. Many scientists got interested in science in such ways, and would welcome you into their labs. Good luck!

Answer 3

Amino acids connect by dehydration synthesis.

Amino acids are available as supplements, but not as vitamins.

Answer 4

Amino acids are the building blocks of peptides (and when in longer chains, polypeptides and proteins), The synthesis of peptides from amino acids is well-characterized:
http://www.protein.iastate.edu/synthesis.html