The main difference between phospholipase A and Phospholipase C is that phospholipase A cleaves fatty acids at the sn-2 position of phospholipids and releases free fatty acids and lysophospholipids, whereas phospholipase C cleaves phospholipids on the sn-3 position and produce inositol trisphosphate and diacylglycerol.
Enzymes are proteins that act as biological catalysts and accelerate various reactions. Some examples of enzymes are catalase, lipase, ligase, phospholipase, etc. Phospholipase is an enzyme that hydrolyses phospholipids into fatty acids and other lipophilic substances. They are also lipolytic enzymes and break down phospholipids at specific ester bonds.
Furthermore, there are four major groups of phospholipases: phospholipase A, phospholipase B, phospholipase C, and phospholipase D. In fact, this classification of phospholipases has a basis on the type of reaction they catalyze. Moreover, phospholipases help in different functions in the body, such as metabolite digestion, lipid mediator production, and signal transduction.
Key Areas Covered
1. What is Phospholipase A
– Definition, Function, Features
2. What is Phospholipase C
– Definition, Function, Features
3. Difference Between Phospholipase A and Phospholipase C
– Comparison of Key Differences
Key Terms
Phospholipase, Phospholipase A, Phospholipase C
What is Phospholipase A
Phospholipase A is a subtype of the enzyme phospholipase. It is an enzyme that cleaves phospholipids at the sn-2 position of phospholipids, resulting in the release of free fatty acids and lysophospholipids. Phospholipase A is produced by a range of bacteria. They are also present in a wide range of gram-negative bacteria, including Salmonella enterica, Helicobactor pylori, Proteus vulgaris, Klebsiella pneumoniae, and Yersinia pseudotuberculosis.
This enzyme is not often toxic, but Y.pseudotuberculosis shows some virulence. Most phospholipase A enzymes are membrane-bound. This group of phospholipase has subgroups like phospholipase A1 and phospholipase A2. Then phospholipase A2 has further sub-categories like secretary phospholipase A2, cytosolic phospholipase A2, and phospholipase A2-like protein (often known as phospholipase A2 domain-containing protein).
What is Phospholipase C
Phospholipase C is a subtype of phospholipase enzyme. Phospholipase C cleaves phospholipids on the sn-3 position to produce inositol trisphosphate and diacylglycerol. Additionally, this is a membrane-associated enzyme. The human form of this enzyme is considered important in eukaryotic cell physiology, especially in signal transduction pathways. In signal transduction, phosphatidylinositol 4,5-bisphosphate is cleaved into diacylglycerol (DAG) and inositol 1,4,5-trisphosphate (IP3), which serve as second messengers. Different signaling molecules, such as small G proteins, receptor/non-receptor tyrosine kinases, Ca2+, and heteromeric G proteins, activate phospholipase C. In addition, some subtypes of phospholipase C function as GTPase activating proteins, guanine nucleotide exchange factors, or adaptor proteins. Studies also show that there are 13 PLC types of isozymes categorized into six classes depending on their structure.
Difference Between Phospholipase A and Phospholipase C
Definition
Phospholipase A is an enzyme that cleaves fatty acids at the sn-2 position of phospholipids, resulting in the release of free fatty acids and lysophospholipids, whereas phospholipase C is an enzyme that cleaves phospholipids on the sn-3 position to produce inositol trisphosphate and diacylglycerol.
Function
Cytosolic PLA2 is involved in inflammatory responses, and secreted PLA2 is involved in cell signaling and membrane repair, whereas phospholipase C plays a vital role in a variety of signaling pathways, including cell growth and differentiation.
Activating Substance
Phospholipid A requires Ca 2+ ions to cleave fatty acids from the phospholipid, whereas phospholipase C is activated by a variety of extracellular signals like hormones and neurotransmitters.
Conclusion
Enzymes are proteins that act as catalysts in a variety of reactions in the body. There is a wide variety of enzymes in living organisms in order to accelerate and efficiently perform biological activities and reactions. The main difference between phospholipase A and Phospholipase C is that phospholipase A cleaves fatty acids at the sn-2 position of phospholipids and releases free fatty acids and lysophospholipids, whereas phospholipase C cleaves phospholipids on the sn-3 position and produce inositol trisphosphate and diacylglycerol.
Reference:
1. “Phospholipase A – An Overview.” Science Direct.
2. “Phospholipase C.” MERCK.
Image Courtesy:
1. “Phospholipases2” By EliseEtc / svg version of – Own work (CC BY-SA 3.0) via Commons Wikimedia
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