Peptide and Protein Synthesis: Building Blocks of Life and Medicine

Elvan Ozkan^*
*Correspondence: Elvan Ozkan, Department of Chemistry, Lahore Garrison University, Lahore, Pakistan, Email:

Keywords

Peptides • Proteins • Amino acids

Introduction

Proteins are the larger and more complex of the two, typically consisting of hundreds to thousands of amino acids. They are involved in a vast array of biological processes, such as enzymes that catalyze chemical reactions, structural proteins that provide support to cells and tissues, transport proteins that carry molecules throughout the body and antibodies that help the immune system fight off infections. Peptides, on the other hand, are shorter chains of amino acids, often comprising only a few to several dozen residues. Despite their smaller size, peptides can have diverse roles in biology, including acting as hormones to regulate bodily functions, neurotransmitters that facilitate communication between nerve cells and antimicrobial peptides that protect against infections. The synthesis of peptides and proteins is a remarkable and highly regulated process that takes place within cells. It is orchestrated by ribosomes; large cellular complexes that read the genetic code stored in DNA and translate it into the precise sequences of amino acids that make up these molecules.

The process begins with the transcription of DNA into messenger RNA (mRNA), a single-stranded molecule that carries the genetic code to the ribosome. The ribosome then reads the mRNA sequence, selecting the appropriate amino acids and linking them together in a specific order according to the instructions encoded in the mRNA. This step-by-step assembly of amino acids is known as translation and it results in the creation of a functional peptide or protein. The specific sequence of amino acids in a peptide or protein, often referred to as the primary structure, determines its unique three-dimensional structure, or tertiary structure. This structure is crucial for the molecule's function, as it determines how the molecule interacts with other biomolecules and its environment. For example, an enzyme's active site, the region where it catalyzes reactions, is defined by its tertiary structure [1,2]. The study and manipulation of peptide and protein synthesis have far-reaching implications in the field of medicine.

Literature Review

The ability to synthesize specific peptides and proteins has opened the door to numerous medical advancements, including the development of novel therapies, vaccines and diagnostic tools. Peptide and protein-based drugs have become essential components of modern medicine. Insulin, for example, is a peptide hormone used to treat diabetes. Additionally, monoclonal antibodies, which are engineered proteins, have revolutionized the treatment of various diseases, including cancer and autoimmune disorders. Many vaccines are based on proteins or peptides from pathogens. By synthesizing these specific components, researchers can create vaccines that train the immune system to recognize and combat harmful microorganisms without causing illness. Peptides and proteins are integral to diagnostic tests. For instance, in immunoassays, specific antibodies are used to detect the presence of certain proteins, hormones, or pathogens in patient samples, enabling the diagnosis of diseases and monitoring of health.

Recombinant DNA technology allows for the creation of genetically modified organisms that can produce therapeutic proteins, such as human insulin or clotting factors for hemophilia treatment. The synthesis and engineering of proteins play a vital role in regenerative medicine. Researchers are exploring the use of growth factors and scaffolding proteins to repair and regenerate damaged tissues and organs. As our understanding of peptide and protein synthesis continues to advance, the possibilities for applications in medicine and other fields are expanding. The development of more efficient and precise methods for synthesizing peptides and proteins is opening up new avenues for drug discovery, personalized medicine and the treatment of previously untreatable conditions. The synthesis of proteins, a fundamental process in biology, relies on a complex molecular machinery within cells. This machinery ensures that the correct sequence of amino acids is assembled to create functional proteins [3,4]. The process of protein synthesis is known as translation and involves several key components and steps. Messenger RNA (mRNA) the process of protein synthesis begins with the transcription of DNA into mRNA. DNA contains the genetic code that determines the sequence of amino acids in a protein.

Discussion

During transcription, an enzyme called RNA polymerase reads a specific gene on the DNA and synthesizes a complementary mRNA molecule. This mRNA molecule carries the genetic information from the nucleus to the ribosomes, which are the cellular structures responsible for protein synthesis. Ribosomes are complex cellular structures made up of ribosomal RNA (rRNA) and proteins. They are often referred to as the "protein factories" of the cell. Ribosomes exist in both the cytoplasm and on the Endoplasmic Reticulum (ER) in eukaryotic cells. The small and large subunits of the ribosome come together during translation to read the mRNA and facilitate the assembly of amino acids into a protein. Transfer RNA (tRNA) molecules are essential for the translation process. Each tRNA molecule carries a specific amino acid and has an anticodon region, which is complementary to the codon on the mRNA. The anticodon on the tRNA base-pairs with the codon on the mRNA, ensuring that the correct amino acid is added to the growing protein chain.

Protein synthesis begins with the initiation phase. The small ribosomal subunit binds to the mRNA molecule and an initiator tRNA with the amino acid methionine binds to the start codon, AUG. This complex then forms the initiation complex. During the elongation phase, the ribosome moves along the mRNA, one codon at a time. As the ribosome advances, it facilitates the binding of the appropriate tRNA molecule to the mRNA codon. The amino acid carried by the tRNA is added to the growing polypeptide chain. The ribosome then shift to the next codon and the process continues. The termination phase marks the end of protein synthesis [5,6]. When the ribosome reaches a stop codon (UAA, UAG, or UGA) on the mRNA, no tRNA with a matching anticodon is available. Instead of an amino acid, a release factor binds to the ribosome, causing the release of the completed protein chain.

Conclusion

Peptides and proteins are the essential building blocks of life and the foundation of modern medicine. Their synthesis is a complex and highly regulated process that underpins many biological processes. The ability to harness the power of peptide and protein synthesis has revolutionized the medical field, enabling the development of life-saving drugs, diagnostic tools and innovative therapies. As our knowledge in this field grows, we can look forward to even more exciting breakthroughs in medicine and beyond. The ribosomal subunits dissociate and the newly synthesized protein is released into the cytoplasm or the endoplasmic reticulum. It's important to note that the process of protein synthesis is highly regulated and accurate. The genetic code is universal, meaning the same codons code for the same amino acids in all organisms. Any errors or mutations in the DNA or the machinery involved in protein synthesis can lead to misfolded or non-functional proteins, potentially resulting in various genetic disorders or diseases. The molecular machinery of protein synthesis is a remarkable and highly orchestrated process that is vital to the functioning of all living organisms. This elegant system ensures the production of a wide array of proteins, each with its own unique sequence and function, contributing to the complexity and diversity of life.

Acknowledgement

None.

Conflict of Interest

None.

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