There are lots of different ways of doing this, depending on how precise you want to be. Mass spectrometry is the most common method for identifying a substance. This is done by breaking the compound down into little pieces of protein and running it through a very big temperamental machine. Each amino acid in a protein is unique, and gives a distinct signature when running through the machine. It then determines what amino acids are in each piece and in what order, and you can compare these against a very big database of protein sequences and see what proteins have the most matches and where in their sequence it is.
New technology exists that we can now do this with genes also, which the human genome project is utilising to completely identify every gene in humans.
But proteins are not just a bunch of amino acids. Their function is determined based on their structure. Their are many different ways to assess how proteins are folded with varying degrees of resolution. The best is X-ray crystallography. This is done by encouraging the protein to crystallise by putting it in a wide range of buffers. Once you have crystals, you can then diffract light through them (sometimes you need a really powerful beam like one at the Australian Synchrotron) and the data that comes back can be run through programs to determine how your protein looks. This is ideally the gold standard, but it is expensive and can take years, and some proteins likethose which live in lipid normally in the membrane are particularly difficult to obtain structures, with only a handful having been done. It also requires a lot of skill and training, which is why we have collaborators who do this part of our studies for us. I am lucky to have had several of my proteins of interest crystallised to high resolution, and you can even see the metal bound to them!
As for single elements, again, when run through the right type of mass spectrometer, they give a specific signal, and you can even determine how much is present by how strong the signal is compared with a range of standards of known concentration. I do this experiment almost every week it seems!
There are several highly advanced machines which can recognize the different components in a mixture. For instance HPLC (high performance liquid chromatorgraphy) is used for identifying, quantifying or purifying the individual components of the mixture. We use mass spectrometry to determine the elemental composition of a sample. If we are interested in the structure of more complex molecules like proteins, we use NMR (nuclear magnetic resonance) and X-ray crystallography.
And we have many databases which stores the data that came out of all the previous recognition studies. For instance if you wonder what 3D structure of insulin (hormone needed by type 1 diabetes patients) look like, follow this link: https://www.bio.davidson.edu/Courses/Molbio/MolStudents/spring2010/Holzwarth/structure.html
There are lots of different ways of doing this, depending on how precise you want to be. Mass spectrometry is the most common method for identifying a substance. This is done by breaking the compound down into little pieces of protein and running it through a very big temperamental machine. Each amino acid in a protein is unique, and gives a distinct signature when running through the machine. It then determines what amino acids are in each piece and in what order, and you can compare these against a very big database of protein sequences and see what proteins have the most matches and where in their sequence it is.
New technology exists that we can now do this with genes also, which the human genome project is utilising to completely identify every gene in humans.
But proteins are not just a bunch of amino acids. Their function is determined based on their structure. Their are many different ways to assess how proteins are folded with varying degrees of resolution. The best is X-ray crystallography. This is done by encouraging the protein to crystallise by putting it in a wide range of buffers. Once you have crystals, you can then diffract light through them (sometimes you need a really powerful beam like one at the Australian Synchrotron) and the data that comes back can be run through programs to determine how your protein looks. This is ideally the gold standard, but it is expensive and can take years, and some proteins likethose which live in lipid normally in the membrane are particularly difficult to obtain structures, with only a handful having been done. It also requires a lot of skill and training, which is why we have collaborators who do this part of our studies for us. I am lucky to have had several of my proteins of interest crystallised to high resolution, and you can even see the metal bound to them!
As for single elements, again, when run through the right type of mass spectrometer, they give a specific signal, and you can even determine how much is present by how strong the signal is compared with a range of standards of known concentration. I do this experiment almost every week it seems!
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There are several highly advanced machines which can recognize the different components in a mixture. For instance HPLC (high performance liquid chromatorgraphy) is used for identifying, quantifying or purifying the individual components of the mixture. We use mass spectrometry to determine the elemental composition of a sample. If we are interested in the structure of more complex molecules like proteins, we use NMR (nuclear magnetic resonance) and X-ray crystallography.
And we have many databases which stores the data that came out of all the previous recognition studies. For instance if you wonder what 3D structure of insulin (hormone needed by type 1 diabetes patients) look like, follow this link: https://www.bio.davidson.edu/Courses/Molbio/MolStudents/spring2010/Holzwarth/structure.html
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