- Amino acids are the building blocks of proteins.
- There are 20 commonly occurring amino acids in proteins.
- Aliphatic side chain amino acids have non-aromatic side chains.
- In this lecture, we will discuss the properties and structures of aliphatic side chain amino acids.
Biomolecules Aliphatic Side Chain Amino Acids
Introduction
Biomolecules Aliphatic Side Chain Amino Acids
Classification of Amino Acids
- Amino acids can be classified based on their side chain properties.
- Aliphatic side chain amino acids have hydrophobic side chains.
- They are non-polar and do not readily dissolve in water.
- Aliphatic side chain amino acids include glycine, alanine, valine, leucine, and isoleucine.
Biomolecules Aliphatic Side Chain Amino Acids
Glycine (Gly, G)
- Glycine is the simplest amino acid.
- It has a hydrogen atom as its side chain.
- Due to its small size, glycine is often found in protein loops and turns.
- Its structural formula is H₂N-CH₂-COOH.
Biomolecules Aliphatic Side Chain Amino Acids
Alanine (Ala, A)
- Alanine has a methyl group (-CH₃) as its side chain.
- It is commonly found in the interior of proteins.
- Alanine is involved in protein stability and function.
- Its structural formula is H₃C-CH(NH₂)-COOH.
Biomolecules Aliphatic Side Chain Amino Acids
Valine (Val, V)
- Valine has a branched side chain.
- It contains three carbon atoms and isopropyl group (-CH(CH₃)₂).
- Valine is an essential amino acid, which means it must be obtained from the diet.
- Its structural formula is (CH₃)₂CH-CH(NH₂)-COOH.
Biomolecules Aliphatic Side Chain Amino Acids
Leucine (Leu, L)
- Leucine also has a branched side chain.
- It contains four carbon atoms and isobutyl group (-CH₂CH(CH₃)₂).
- Leucine is important for the synthesis of muscle proteins.
- Its structural formula is CH₃-CH₂CH(CH₃)₂-CH(NH₂)-COOH.
Biomolecules Aliphatic Side Chain Amino Acids
Isoleucine (Ile, I)
- Isoleucine is another branched side chain amino acid.
- It contains four carbon atoms and sec-butyl group (-CH(CH₃)CH₂CH₃).
- Isoleucine is essential for the growth and development of muscle tissue.
- Its structural formula is CH₃-CH(CH₃)CH₂CH(CH₃)-CH(NH₂)-COOH.
Biomolecules Aliphatic Side Chain Amino Acids
aliphatic side chain
- The aliphatic side chain amino acids are hydrophobic, meaning they do not readily dissolve in water.
- They are typically found in the interior of proteins, away from the aqueous environment.
- The hydrophobic nature of these amino acids contributes to protein folding and stabilization.
- The non-polar side chains of aliphatic side chain amino acids allow for interactions with other non-polar residues.
- These interactions can contribute to the overall structure and stability of the protein.
Biomolecules Aliphatic Side Chain Amino Acids
Hydrocarbon chains
- The hydrophobicity of aliphatic side chain amino acids is due to the presence of hydrocarbon chains.
- Hydrocarbon chains consist solely of carbon and hydrogen atoms bonded together.
- Since carbon and hydrogen have similar electronegativities, these bonds are non-polar.
- This non-polarity leads to the hydrophobic nature of the aliphatic side chains.
Biomolecules Aliphatic Side Chain Amino Acids
hydrophobic interactions
- Aliphatic side chain amino acids can participate in various interactions within a protein.
- They can form hydrophobic interactions with other nonpolar residues.
- These interactions contribute to the hydrophobic core of a protein, which helps stabilize its tertiary structure.
- In addition to hydrophobic interactions, aliphatic side chain amino acids can also participate in van der Waals interactions.
- Van der Waals forces are weak, but they play a significant role in maintaining the overall stability and structure of proteins.
Biomolecules Aliphatic Side Chain Amino Acids
Glycine and alanine
- The aliphatic side chain amino acids glycine, alanine, valine, leucine, and isoleucine have different physical and chemical properties.
- Glycine is the smallest amino acid and is highly flexible due to the absence of a side chain.
- Alanine is a small, non-polar amino acid that plays a role in protein stability.
- Valine, leucine, and isoleucine are all hydrophobic and non-polar, but have different branching patterns in their side chains.
Biomolecules Aliphatic Side Chain Amino Acids
three branched aliphatic side chain
- The three branched aliphatic side chain amino acids, valine, leucine, and isoleucine, have similar structures due to their branching.
- The branched nature of their side chains restricts their conformational flexibility.
- This constraint can affect their interactions with other residues in a protein and influence protein folding.
- The presence of branched aliphatic side chains can also affect the hydrophobicity and lipophilicity of these amino acids.
Biomolecules Aliphatic Side Chain Amino Acids
biological processes
- Aliphatic side chain amino acids are involved in several biological processes.
- They are essential for protein synthesis and play a crucial role in the structure and function of proteins.
- Aliphatic side chain amino acids are also involved in metabolic pathways, such as energy production and the synthesis of certain molecules.
- Additionally, some aliphatic side chain amino acids have special functions, such as leucine’s role in activating protein synthesis through the mTOR pathway.
Biomolecules Aliphatic Side Chain Amino Acids
hydrophobicity and properties
- The hydrophobicity of the aliphatic side chain amino acids also plays a role in protein-protein interactions.
- Hydrophobic residues can interact with exposed hydrophobic patches on other proteins.
- These interactions can be involved in protein-protein recognition, binding, and the formation of multiprotein complexes.
- The hydrophobicity and overall properties of the aliphatic side chains contribute to the specificity and stability of protein-protein interactions.
Biomolecules Aliphatic Side Chain Amino Acids
chemical properties
- The aliphatic side chain amino acids have different chemical properties that can be utilized in various applications.
- For example, glycine is used in the production of pharmaceuticals, food additives, and in the synthesis of polymers.
- Alanine is an important amino acid in the food and pharmaceutical industries due to its sweet taste and stability.
- Valine, leucine, and isoleucine are used as dietary supplements, particularly in sports nutrition, due to their role in muscle protein synthesis.
Biomolecules Aliphatic Side Chain Amino Acids
critical roles
- The aliphatic side chain amino acids are essential for the proper functioning of the human body.
- They play critical roles in muscle development, tissue repair, and overall metabolism.
- A deficiency in any of these amino acids can lead to health issues and may require dietary supplementation.
- It is important to consume a balanced diet that provides all essential amino acids to support optimal health and well-being.
Biomolecules Aliphatic Side Chain Amino Acids
Summary
- In summary, aliphatic side chain amino acids are important building blocks of proteins.
- They have hydrophobic and non-polar properties, which contribute to protein folding, stability, and protein-protein interactions.
- Understanding the characteristics of aliphatic side chain amino acids is crucial for the study of protein structure and function.
- These amino acids have diverse roles in the body, and their deficiencies can impact overall health.
Biomolecules Aliphatic Side Chain Amino Acids
Conclusion
- In conclusion, aliphatic side chain amino acids are important biomolecules that play critical roles in protein structure, function, and cellular processes.
- Their hydrophobic properties, unique structures, and interactions with other amino acids contribute to the diversity and specificity of protein structures.
- Understanding the properties and functions of aliphatic side chain amino acids is essential in biochemistry and related fields.
Biomolecules Aliphatic Side Chain Amino Acids Introduction Amino acids are the building blocks of proteins. There are 20 commonly occurring amino acids in proteins. Aliphatic side chain amino acids have non-aromatic side chains. In this lecture, we will discuss the properties and structures of aliphatic side chain amino acids. $\rightarrow$ $\rightarrow$ Introduction $\rightarrow$ Classification of Amino Acids $\rightarrow$ Glycine (Gly, G)