What is the Difference Between Beta Alanine and L Alanine

The main difference between beta-alanine and L alanine is that beta-alanine is a non-proteogenic amino acid, whereas L alanine is a proteogenic amino acid.

Beta-alanine and L alanine are two types of amino acids with the same chemical formula: C₃H₇NO₂. Both are naturally occurring amino acids.

Key Areas Covered

1. What is Beta Alanine
     – Definition, Structure, Function
2. What is L Alanine
     – Definition, Structure, Function
3. Similarities Between Beta Alanine and L Alanine
     – Outline of Common Features
4. Difference Between Beta Alanine and L Alanine
     – Comparison of Key Differences

Key Terms

Beta Alanine, L Alanine

What is Beta-Alanine

Beta-alanine is a non-essential amino acid naturally occurring in food sources such as meat, fish, and poultry. It contains an amino group attached to the beta-carbon. Therefore, beta-alanine does not contain a stereocenter. It is also a non-proteogenic amino acid that does not involve protein synthesis. However, the degradation of dihydrouracil and carnosine is responsible for the biosynthesis of beta-alanine. Carnosine plays an important role in muscle endurance in high-intensity exercises. Carnosine occurring in muscles, on the other hand, allows muscles to perform long periods of time before becoming fatigued. Therefore, beta-alanine helps in enhancing sports and endurance.

Figure 1: Beta-Alanine

Furthermore, the limiting factor of the carnosine levels is the availability of beta-alanine. Beta-alanine is also a rare compound. But the supplements of beta-alanine increase the carnosine levels in muscles. Therefore, beta-alanine supplements increase the strength and endurance of muscles.

What is L Alanine

L alanine is a proteogenic amino acid important in the synthesis of proteins. It contains both the carboxyl group and amino group attached to the alpha carbon. L alanine is a non-essential amino acid, and the body produces L alanine during metabolism. L alanine also participates in the breakdown of tryptophan and vitamin B6. The main function of L alanine is to involve in protein synthesis. It is a constituent of all proteins and peptides that occur in the body. Another function of alanine is to involve in energy production. There, L alanine undergoes transamination to release pyruvate. The complete oxidation of alanine can produce 3.425 kcal/ g of energy.

Figure 2: L Alanine

Moreover, L alanine participates in the glucose-alanine cycle, in which the freest alanine is transported into the circulation. In the liver, these amino acids participate in urea synthesis, and the residual pyruvate is used for gluconeogenesis.

Similarities Between Beta Alanine and L Alanine

• Beta-alanine and L alanine are two types of amino acids that occur in nature.
• Both contain the chemical formula C₃H₇NO_2.

Difference Between Beta Alanine and L Alanine

Definition

Beta-alanine refers to a non-essential amino acid, while L alanine refers to an α-amino acid that is used in the biosynthesis of proteins.

Amino Group                        

The amino group is attached to the beta-carbon in beta-alanine, while the amino group is attached to the alpha-carbon in L alanine.

Stereochemistry

Beta-alanine does not contain a stereocenter, while L-alanine contains a stereocenter.

Importance

Beta-alanine is important in muscle endurance during exercises, while L alanine is important in the biosynthesis of proteins.

Proteogenic Amino Acids

Beta-alanine is a non-proteogenic amino acid, while L alanine is a proteogenic amino acid.  

Conclusion                                                     

In brief, beta-alanine and L alanine are two types of amino acids that occur in nature. Beta-alanine contains the amino group attached to the beta carbon. Therefore, it does not contain a stereocenter. It is important for muscle endurance during exercises. But it is a non-proteogenic amino acid. In comparison, L alanine contains an amino group attached to the alpha carbon and hence, contains a stereocenter. L alanine is important in the synthesis of proteins. Therefore, L alanine is a proteogenic amino acid. The main difference between beta-alanine and L alanine is the proteogenic nature of the amino acids.

References:       

1. Beta-alanine: Uses and risks. WebMD. 
2. Alanine. An Overview | ScienceDirect Topics. 

Image Courtesy:

1. “Beta-alanine structure” By User:Mysid – Own work (Public Domain) via Commons Wikimedia
2. “L-Alanin – L-Alanine” By NEUROtiker – Own Work (Public Domain) via Commons Wikimedia