Understand Difference

Trypsin and Chymotrypsin: The Dynamic Duo of Protein Digestion

Introduction to Trypsin and

Chymotrypsin

Protein digestion is the process by which proteins are broken down into individual amino acids. This is an essential process in the human body, as amino acids are the building blocks of proteins and are used for the synthesis of cellular components, enzymes, hormones, and other crucial biological molecules.

Enzymes play a critical role in protein digestion, as they catalyze the hydrolysis of peptide bonds, breaking down the protein into smaller peptide fragments, ultimately yielding amino acids. Two important enzymes involved in protein digestion are trypsin and chymotrypsin.

These serine proteases are found in the pancreas and play significant roles in the digestion of dietary proteins. In this article, we will explore the differences between trypsin and chymotrypsin, their mechanisms of action, structures, inhibitors and applications.

Differences between Trypsin and

Chymotrypsin

The major difference between trypsin and chymotrypsin is their specificity towards peptide bonds. Trypsin cleaves peptide bonds on the C-terminal end of positively charged amino acids such as arginine and lysine.

In contrast, chymotrypsin cleaves peptide bonds on the C-terminal end of aromatic amino acids such as phenylalanine, tryptophan, and tyrosine. Another difference between trypsin and chymotrypsin is their cleavage position.

Trypsin cleaves peptide bonds on the carboxyl (C)-terminal side of basic amino acids, whereas chymotrypsin cleaves peptide bonds on the C-terminal side of hydrophobic amino acids. The specific action of these enzymes is crucial in the digestion of proteins because it allows for the specificity and efficiency of protein hydrolysis.

Mechanism of Action and Substrates for Trypsin

Trypsin catalyzes the hydrolysis of peptide bonds between the carboxyl (C) -terminal of a lysine or arginine residue and an adjacent peptide bond, primarily in the small intestine. Under normal physiologic conditions, trypsinogen, which is the inactive precursor to trypsin, is first secreted by the pancreas, and then activated to trypsin in the small intestine by the enzyme enterokinase.

Trypsin has high specificity towards basic amino acids such as lysine and arginine, cleaving the peptide bond at these residues to produce shorter peptide fragments. These peptides are further hydrolyzed by other proteolytic enzymes to release free amino acids, which can be absorbed by the intestines and transported to various cells in the body.

Types and Structure of Active Trypsin

Trypsin exists in two forms, alpha-trypsin and beta-trypsin, which have slightly different structures. Alpha-trypsin contains calcium ions and is more resistant to heat denaturation than beta-trypsin.

The activity of trypsin depends on its structure, and both alpha-trypsin and beta-trypsin have different conformations, which can be affected by many factors, such as temperature, pH, and the presence of inhibitors. The structure of trypsin is complex, and it consists of two domains, the N-terminal domain, and the catalytic domain.

The N-terminal domain is used to stabilize the enzyme and enhance its thermal stability, while the catalytic domain contains all the active sites of the enzyme. The catalytic domain consists of 6 active site loops and a catalytic triad composed of the residues His-57, Asp-102, and Ser-195, which forms a hydrogen bond network that stabilizes the transition state of the enzymatic reaction.

Inhibitors and Applications of Trypsin

Several inhibitors can block the activity of trypsin, including diisopropyl fluorophosphate (DFP), aprotinin, Ag+, benzamidine, and ethylenediaminetetraacetic acid (EDTA). DFP and aprotinin are commonly used in studies of enzyme kinetics, proteomics, and biochemistry to determine the specific activity and substrate specificity of trypsin.

Aprotinin is also used as an inhibitor in the dissociation of tissue, which allows cells and tissues to be separated into their individual components for further study. Trypsin is also used in cell culture studies to digest protein in extracellular matrices, which increases cell viability and proliferation, and in fingerprinting to digest proteins and generate peptide mass spectra for protein identification.

Moreover, trypsin is widely used in the food industry as a tenderizer, in meat processing, and in the production of other foods.

Conclusion

Protein digestion involves the breakdown of proteins into amino acids, which are essential for cellular activities. Enzymes are crucial for protein digestion, and trypsin and chymotrypsin are two important enzymes involved in this process.

Trypsin cleaves peptide bonds specific to basic amino acids, while chymotrypsin cleaves peptide bonds specific to aromatic amino acids. The specificity of these enzymes is essential for the efficient and specific digestion of proteins.

Trypsin is mainly produced in the pancreas and plays a critical role in protein digestion in the small intestine, and it is also used in many research studies and in the food industry for various purposes.

Chymotrypsin

Chymotrypsin is a serine protease found in the digestive system of many animals, including humans. It is also known as alpha-chymotrypsin or chymotrypsin A, and it plays a significant role in the breakdown of dietary proteins into smaller peptides and amino acids.

In this article, we will explore the discovery, mechanism of action, structure, and applications of chymotrypsin.

Overview and Discovery

Chymotrypsin was discovered in the mid-19th century by the Scottish physiologist Thomas Wharton Jones, who noted the digestive properties of pancreatic juice containing an unknown proteolytic enzyme. Later, in 1931, the American biochemist Max Bergmann and his colleagues isolated chymotrypsin as a crystalline substance from pancreatic extracts.

Chymotrypsin is produced in the pancreas as an inactive precursor, chymotrypsinogen, and is activated to chymotrypsin in the small intestine by the enzyme trypsin.

Chymotrypsin is a typical serine protease, which means that it contains an active site with a serine residue that acts as a nucleophile during catalysis.

Mechanism of Action and Substrates

Like trypsin, chymotrypsin hydrolyzes peptide bonds, but its specificity is different.

Chymotrypsin cleaves peptide bonds on the C-terminal end of large hydrophobic or aromatic amino acids such as phenylalanine, tryptophan, and tyrosine.

It also cleaves bonds involving leucine, methionine, and alanine residues with larger side chains.

Chymotrypsin catalyzes hydrolysis by the same general mechanism as trypsin, with a catalytic triad of amino acid residues, but with different amino acid side chains. The catalytic mechanism involves the use of a serine residue in the active site to attack the carbonyl carbon of the peptide bond between the C-terminal amino acid and its adjacent residue.

This forms an acyl-enzyme intermediate, which is then hydrolyzed by activated water molecules to release the C-terminal peptide fragment.

In addition to peptide bonds, chymotrypsin can also cleave amides and esters with bulky L-isomers.

This broad specificity enables it to contribute significantly to protein digestion in the small intestine. Types and Structure of

Chymotrypsin

Chymotrypsin is classified into two types: chymotrypsin A and chymotrypsin B. Both types are similar but differ slightly in structural and proteolytic characteristics.

The crystal structures of both enzymes have been determined, and they have similar active sites consisting of a catalytic triad and a hydrophobic pocket that accommodates the side chains of the amino acids targeted for cleavage. Activators and Inhibitors of

Chymotrypsin, and Applications

Chymotrypsin activity is regulated by both activators and inhibitors. The activators of chymotrypsin include various surfactants such as cetyltrimethylammonium bromide, dodecyltrimethylammonium bromide, hexadecyltrimethylammonium bromide, and tetrabutylammonium bromide.

These activators enhance the solubility of the hydrophobic substrates and increase the stability of the enzyme during hydrolysis. Inhibitors of chymotrypsin include peptidyl aldehydes, boronic acids, and coumarin derivatives, which bind to the enzyme’s active site, preventing hydrolysis.

Some of the applications of chymotrypsin include peptide synthesis, protein mapping, and fingerprinting. It is used in industries, such as the production of food, cosmetics, and pharmaceuticals, and as a cleaning agent for surgical instruments.

Similarities between Trypsin and

Chymotrypsin

Trypsin and chymotrypsin are both serine proteases involved in protein digestion in the small intestine. Like trypsin, chymotrypsin contains an active site with a catalytic triad and a serine residue that acts as a nucleophile during the catalytic process.

Both enzymes have a basic pH environment for optimal activity, and they are produced as inactive zymogens that are activated in the small intestine. Moreover, trypsin and chymotrypsin, like other serine proteases, are commercially produced using recombinant DNA technology.

They are used in many in vitro industries, such as the production of peptides, protein mapping, and the analysis of protein structures.

Conclusion

Chymotrypsin is a crucial enzyme involved in protein digestion in the small intestine, and its broad specificity enables it to hydrolyze various peptide bonds in hydrophobic amino acids. It is classified into two types, A and B, with distinct proteolytic characteristics but similar structural features.

Chymotrypsin is regulated by various activators and inhibitors, and its applications range from peptide synthesis to the production of food, cosmetics, and pharmaceuticals. The similarities between trypsin and chymotrypsin indicate the importance of these serine proteases in the digestion and analysis of proteins.

Conclusion

In summary, trypsin and chymotrypsin are two crucial enzymes involved in protein digestion and play significant roles in catalyzing the hydrolysis of peptide bonds. Although both enzymes share similarities, such as being serine proteases and having a catalytic triad, there are notable differences between them in terms of their specificity toward peptide bonds and cleavage points.

Trypsin cleaves peptide bonds on the C-terminal ends of basic amino acids, mainly arginine and lysine. In contrast, chymotrypsin cleaves peptide bonds on the C-terminal end of large hydrophobic or aromatic amino acids, such as phenylalanine, tryptophan, and tyrosine.

Moreover, chymotrypsin can cleave other residues such as leucine, methionine, and alanine with large side chains. Another distinguishing feature of trypsin and chymotrypsin is their structure and types.

Trypsin and chymotrypsin have different conformations, and their structures differ due to the variations of their amino acid residues.

Chymotrypsin is composed of chymotrypsin A and chymotrypsin B types, which have similar properties but differ slightly in their substrate specificity.

Furthermore, both trypsin and chymotrypsin are commercially produced using recombinant DNA technology, which has significant implications in the production of various products, such as the enzymes themselves, peptides, and other proteins. Despite their differences, trypsin and chymotrypsin share several similarities.

Both enzymes are synthesized as inactive zymogens, which are activated in the small intestine, enabling them to work optimally in the digestive process. They both have optimal activities in the basic pH environment.

Moreover, they have applications in many industries, ranging from food to pharmaceutical production. In conclusion, trypsin and chymotrypsin are essential enzymes involved in the digestion of dietary proteins, and they are critical in providing amino acids, which are essential for various functions in the body.

Understanding the different characteristics and similarities of these enzymes can improve their applications in many industries, including biotechnology, and provide new insights into the digestive process of different proteins. In conclusion, trypsin and chymotrypsin are vital enzymes in protein digestion, breaking down dietary proteins into smaller peptides and amino acids.

While trypsin cleaves peptide bonds at basic amino acids, chymotrypsin targets hydrophobic or aromatic amino acids. Despite their differences, both enzymes are produced as zymogens and play critical roles in the digestive process.

Understanding the unique characteristics of trypsin and chymotrypsin aids in applications ranging from food production to pharmaceuticals. The study of these enzymes broadens our understanding of protein digestion and highlights the importance of enzymatic processes in maintaining our overall health.

Popular Posts