What is the Difference Between Beta Alanine and L Alanine

The key difference between beta alanine and L alanine is that beta alanine is a non-proteinogenic amino acid while L alanine is a proteinogenic amino acid.

Generally, amino acids are the building blocks of proteins. They combine with each other to form proteins. There are two groups of amino acids as non-proteinogenic and proteinogenic. Non-proteinogenic amino acids are not normally incorporated into proteins during the translational process. Some examples of non-proteinogenic amino acids are GABA, L-DOPA, triiodothyronine, and beta alanine. Proteinogenic amino acids, on the other hand,  are the amino acids that are incorporated into proteins during translation. In eukaryotes, there are 21 proteinogenic amino acids. Some examples of proteinogenic amino acids are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, L alanine, valine, etc.

CONTENTS

1. Overview and Key Difference
2. What is Beta Alanine  
3. What is L Alanine
4. Similarities – Beta Alanine and L Alanine
5. Beta Alanine vs L Alanine in Tabular Form
6. Summary – Beta Alanine vs L Alanine

What is Beta Alanine?

Beta alanine is a non-proteinogenic amino acid. It is a naturally occurring beta amino acid. In beta alanine, the amino group of amino acids is attached to the β carbon rather than the more usual α carbon. The IUPAC name for the beta alanine is 3-aminopropanoic acid. Unlike alpha alanine, beta alanine has no stereocenter. A stereocenter is any point of a molecule bearing different substituents. The interchanging of any two substituents at the stereocenter leads to the formation of stereoisomer.

Though beta alanine is a non-proteinogenic amino acid, it is said to be the precursor to carnosine peptide by rate limitation. Moreover, increasing the amount of beta alanine will increase the total concentration of carnosine in muscles. Carnosine reduces fatigue and helps to develop leaner muscles. People who would like to develop their muscles normally take in beta alanine supplementation to further increase their natural beta alanine storage. As supplementation with beta alanine increases, the carnosine concentration in muscles ultimately increases the muscular work out performance in athletes. Furthermore, beta alanine is also a residue of anserine (dipeptide) and pantothenic acid (vitamin B₅).

What is L Alanine?

L alanine is a proteinogenic amino acid. The L isomer of alanine is the one that is usually incorporated into proteins. L alanine amino acid is only second to leucine in the rate of occurrence. It was proved that L alanine accounts for 7.8 % of the primary structure in a sample of 1150 proteins. On the other hand, D alanine occurs in only polypeptides in some bacterial cell walls. In L alanine, the amino group of amino acids is attached to the usual α carbon. Moreover, it also has stereoisomers.

The IUPAC name of L alanine is 2-aminopropanoic acid. L alanine is a non-essential amino acid. It is normally produced enzymatically from L aspartate using aspartate β decarboxylase. It is the smallest of all amino acids. L alanine has been used as a supplement in cell culture media. Furthermore, L alanine is used as a food additive, an ingredient in infusion solutions, and a precursor for chemical and pharmaceutical products

What are the Similarities Between Beta Alanine and L Alanine?

• Beta alanine and L alanine are two structurally different amino acids.
• They are naturally occurring amino acids.
• Both amino acids have the same molecular formula: C₃H₇NO₂.
• These amino acids have different applications.

What is the Difference Between Beta Alanine and L Alanine?

Beta-alanine is a non-proteinogenic amino acid, while L alanine is a proteinogenic amino acid. Thus, this is the key difference between beta alanine and L alanine. Furthermore, in beta-alanine, the amino group of amino acid is attached to the β carbon, but in L alanine, the amino group of amino acid is attached to the α carbon.

The below infographic presents the differences between beta alanine and L alanine in tabular form for side by side comparison.

Summary – Beta Alanine vs L Alanine

Amino acids are organic molecules that combine to form proteins. Beta alanine and L alanine are two different amino acids. Beta alanine is a non-proteinogenic amino acid, while L alanine is a proteinogenic amino acid. So, this is the key difference between beta alanine and L alanine.

Reference:

1.  McMillen, Matt. “Beta-Alanine: Uses and Risks.” WebMD.
2. “Alpha-Alanine: Overview, Uses, Side Effects, Precautions, Interactions, Dosing and Reviews.” WebMD.

Image Courtesy:

1. “Beta alanine comparison” (CC BY-SA 3.0) via Commons Wikimedia
2. “L-Alanine” (CC BY-SA 3.0) via Commons Wikimedia