Methionine Amino Acid Structure

One thing that methionine is known for is that it is being converted to certain sulfur-containing compounds. And some of these compounds actually have the function of protecting tissues in the body.

amino acid structure model

There are about 20 common amino acids. Now, this does not mean that there are no other amino acids in nature. It just means that the ones many people are familiar with are these 20. Some of these amino acids are referred to as the essential amino acids, which include methionine. We will be taking a closer look at what this amino acid is all about. One important thing we will be looking at today is the methionine amino acid structure. Well, you will find out as we go on why this is important. 

You must take note that even though amino acids are a bit similar they have their differences. And one of the major differences happens to their structure. In the structure of amino acids, they have some things in common which happen to be the amino group and the carboxyl group.

One thing that differentiates all the amino acids is their side chain. The side chain would also determine which group the amino acid belongs to. Well, you will find out all these about methionine as we go on. So keep reading because there is more to come. 


Let’s have a look at how this amino acid was named and discovered first. This amino acid was actually discovered by a man named J.H.Muller. This man worked as a researcher at Columbia University which is located in New York. And in the year 1922, this man discovered the amino acid methionine. At that time he was able to isolate the amino acid but the summation formula submitted was wrong.

So after 3 years one of his fellow researchers Odake corrected it. It was Odake that actually gave methionine its names. Three years after Barger and Coyne were able to identify the structure of this amino acid. We will be looking at the structure better later on.  

Methionine, as mentioned earlier, is one of the essential amino acids needed by the body. And this amino acid actually helps produce some other important molecules in the body. and some of these molecules are actually very important for certain functions carried out in the body.

For this reason, some recommend that methionine intake should be increased. While for some, the intake of methionine should be reduced because of the negative side effects that come with it. 

One thing that methionine is known for is that it is being converted to certain sulfur-containing compounds. And some of these compounds actually have the function of protecting tissues in the body. At the same time, they help maintain the functioning of cells in the body and modify DNA as well. The reason why methionine is the chosen amino acid for making some of these compounds is that it contains sulfur. 

Another big role of methionine is in the production of protein. The starting process of making any protein needs methionine. That’s because of methionine codes for the start codon in the production of protein. The absence of the start codon automatically means there would be a problem with the production of protein. So the role of methionine in the body can’t be underestimated. 

Methionine Amino Acid Structure 

Methionine is classified as a non-polar aliphatic amino acid. This amino acid is often abbreviated as Met or M. And it happens to be encoded as the codon AUG. AUG is actually known as the start codon in the synthesis of protein. So the synthesis of protein only starts when the start codon (AUG) is present. 

In terms of its chemical structure, it contains the amino group and the carboxyl group. These two groups are common to every amino acid. Its side chain is the S-methyl thioether. It contains sulfur and it happens to be the second amino acid together with cysteine that contains sulfur. That’s one of the reasons why this amino acid is known to be very useful in the body.

Roles of Methionine in The Body 

Helps produce other molecules

Methionine is one of those amino acids that are important for the production of certain molecules in the body. One of the molecules being produced is cysteine. Cysteine is actually an amino acid that contains sulfur just methionine. And this amino acid is actually very important for the production of proteins in the body.

Also, cysteine is important for the production of taurine and glutathione. Glutathione is one of the most important antioxidants in the body. In fact, it’s known to be the master antioxidant. And it has a large role in protecting the body. Taurine as well as the function of maintaining health. 

DNA methylation

You already knows that the DNA contains the information that makes up a person. Most of the time your DNA remains the same and the information in it remains the same. But there are times that there are changes due to certain environmental factors.

What methionine does is that it is converted to a molecule known as SAM. It is this molecule that now adds a methyl group to DNA. The thing though is that the changes in DNA can be either beneficial or harmful to the body. That’s why some people advise that methionine should be consumed in smaller quantities in the body and not too much. 

May extend lifespan

Some research shows that diets low in methionine might actually help extend the lifespan of a person. It has been found out that there some cancer cells that might be dependent on the amino acid methionine. So consuming smaller amounts of methionine would affect the growth of those cancerous cells. And that would extend the lifespan.

There are also studies that have been carried out on animals that prove that this might be true. The effect of methionine on human cells isn’t yet fully understood. More studies and research is still needed to fully understand this. 

From all indications, methionine is one of the important amino acids in the body. that’s why it’s important to understand the methionine amino acid structure. This way you would have an idea of what the amino acid methionine is all about.

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