Question

Which of the following is NOT a correct statement about phospholipase A2?

• A. It releases fatty acid from glycerol during inflammation
• B. It is found in mammals
• C. It is found in snake venom
• D. It does not have any isozyme

Hint:

Phospholipase A2: Cleaves $sn-2$ fatty acid (Arachidonic acid) from phospholipids. Found in mammals and snake venoms. Has MULTIPLE isozymes ($ ext{sPLA}_2, ext{cPLA}_2, ext{iPLA}_2$).

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Phospholipase A2 ($ ext{PLA}_2$) enzymes constitute a diverse superfamily of multiple distinct secretory, cytosolic, and calcium-independent isozymes.
Key Formula or Approach:
\[ \text{Phosphoglyceride} + \text{H}_2\text{O} \xrightarrow{\text{Phospholipase A}_2} \text{Lysophospholipid} + \text{Free Fatty Acid (Arachidonate from } sn\text{-2)} \]

Step 2: Detailed Explanation:
Evaluating the biochemical properties of Phospholipase A2 ($\text{PLA}_2$):
1. Option 1 (True): Specifically hydrolyzes the ester bond at the $sn-2$ position of membrane phospholipids, liberating free arachidonic acid to drive inflammatory prostaglandin/leukotriene synthesis.
2. Option 2 (True): Widely distributed in mammalian tissues (pancreas, synovial fluid, platelets, macrophages).
3. Option 3 (True): Abundant toxic component of viper and elapid snake venoms, causing hemolysis and neurotoxicity.
4. Option 4 (INCORRECT): $\text{PLA}_2$ exists as multiple distinct isozyme families (secretory $\text{sPLA}_2$, cytosolic $\text{cPLA}_2$, calcium-independent $\text{iPLA}_2$, and lipoprotein-associated $\text{Lp-PLA}_2$).
Therefore, stating that it has no isozymes is incorrect.

Step 3: Final Answer:
Thus, 'It does not have any isozyme' is NOT a correct statement, matching option (D).