Difference Between Lyases and Transferases

The key difference between lyases and transferases is their primary function. Lyases are enzymes that catalyze the dissociation or breakdown of molecules by cleaving the bonds between them. Meanwhile, transferases are enzymes that catalyze the transferring of a functional group from one molecule to another molecule. 

Enzymes are biocatalysts of biochemical reactions. They are proteins, and they speed up the biochemical reactions by lowering the activation energy of the reaction. Therefore, they increase the rate of the reaction without being consumed. They can catalyze biochemical reactions again and again. Based on the reaction the enzymes catalyze, there are six groups of enzymes. They are the transferase, ligase, oxidoreductase, isomerase, hydrolase, and lyase. Of these, the lyases catalyze the cleaving of molecules while the transferases catalyze the transferring of groups between molecules.

CONTENTS

1. Overview and Key Difference
2. What are Lyases 
3. What are Transferases
4. Similarities Between Lyases and Transferases
5. Side by Side Comparison – Lyases vs Transferases in Tabular Form
6. Summary

What are Lyases?

Lyases are enzymes that catalyze the breakdown or dissociation of molecules. The enzymes use water or redox reactions in order to cleave bonds between molecules. Lyases normally cleave C-C, C-N and C-O bonds between molecules. Often this leads to the formation of double bonds between molecules. It also leads to the formation of ring structures. Lyases differ from hydrolases due to not adding water into the products. Common lyases include decarboxylases, aldolases, dehydratases, etc.

An example of a biochemical reaction that catalyzes by a lyase is illustrated below.

ATP → cAMP + PP_i

What are Transferases?

Transferases are enzymes that catalyze the transferring of a functional group from one molecule to another molecule. Therefore, transferases facilitate the transfer of a group from a donor molecule to an acceptor molecule. Kinases are the best example of transferases. They catalyze the transfer of a phosphate group from ATP to some other molecule. The functional groups that transfer by transferases include methyl, glycosyl, aldehyde, ketone, alkyl or aryl, alcohol and carboxyl, etc. Based on the functional group, there are subclasses of transferases.

Coenzyme A (CoA) transferase, peptidyl transferase, uridyl transferase, catechol-O-methyltransferase, methylamine-glutamate N-methyltransferase, nucleotidyl transferase, acyltransferase, glycosyltransferase, hexosyltransferase, and pentosyltransferase are several examples of transferases.

What are the Similarities Between Lyases and Transferases?

• Lyases and transferases are two of the six major groups of enzymes.
• They catalyze biochemical reactions and increase the rate of reaction by lowering the activation energy.
• They are made from amino acid sequences. Hence, they are proteins and have an active site to bind with their specific substrates.
• They are involved with many important biochemical pathways in living organisms.
• In fact, they are integral parts of important processes in life.

What is the Difference Between Lyases and Transferases?

Lyase is an enzyme that catalyzes the breaking of various chemical bonds by means other than hydrolysis and oxidation. Meanwhile, transferase is an enzyme that catalyzes the transferring of a functional group from donor to acceptor. So, this is the key difference between lyases and transferases. Decarboxylases, aldolases, dehydratases, etc. are several examples of lyases. And, coenzyme A (CoA) transferase, peptidyl transferase, uridyl transferase, catechol-O-methyltransferase, methylamine-glutamate N-methyltransferase, nucleotidyl transferase, acyltransferase, glycosyltransferase, hexosyltransferase, and pentosyltransferase are several examples of transferases.

Below infographic summarizes the difference between lyases and transferases.

Summary – Lyases vs Transferases

Lyases catalyze the breaking of various chemical bonds by means other than hydrolysis and oxidation. Therefore, lyases cleave chemical bonds and promote the breakdown of molecules by forming double bonds between C molecules and forming ring structures. Meanwhile, transferases catalyze the transfer of functional groups from one molecule to another. Thus, this is the key difference between lyase and transferase. Both lyases and transferases are two important groups of enzymes that are integral parts of many important biochemical reactions occurring in life.

Reference:

1. “Transferase.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 13 Apr. 2009, Available here.
2. “Structural Biochemistry/Enzyme Catalytic Mechanism/Enzyme Classification/Lyases.” Structural Biochemistry/Enzyme Catalytic Mechanism/Enzyme Classification/Lyases – Wikibooks, Open Books for an Open World, Available here.

Image Courtesy:

1. “Prenylcysteine lyase mechanism” By UMcrc14 – Own work (CC BY-SA 4.0) via Commons Wikimedia
2. “Transaldolase reaction” By Yikrazuul – Own work (CC BY-SA 3.0) via Commons Wikimedia