. 2023 Jan 10;24(2):1353. doi: 10.3390/ijms24021353

Table 1.

The main groups and subgroups of PLA2s.

Type	Group	Subgroup	Source	Molecular Weight (kDa)	Catalytic Residues	Substrate Specificity	Secreting Cells	Ref.
sPLA2	I	A	Cobras/kraits	13–15	His/Asp Ca²⁺ is required for substrate binding and catalysis	More active against zwitterionic PC		[6]
	I	B	Human/porcine pancreas	13–15			Pancreatic acinar cells	[9]
	II	A	Rattlesnake, human synovial fluid	13–15		High affinity for anionic phospholipids such as PE, PG, PS	Synovial fluid, tears, leukocytes, platelets, macrophages, monocytes, T-cells, neutrophils	[6,9]
	II	B	Gaboon viper	13–15				[7]
	II	C	Rat/murine testis	15				[7]
	II	D, E, F	Human/murine pancreas/brain/spleen/heart/uterus/embryo/testis	14–17			G-IID in lymph tissue DC; G-IIE in hypertrophic adipocytes. These are also expressed in macrophages and smooth muscle cells	[9]
	III		Lizard/bee	15–18		Sperm membrane phospholipid remodeling	CNS, peripheral, neural fibers, mast cells, epididymal epithelium	[9,10]
	V		Human/murine macrophage/heart/lung	14		High affinity for cell membrane PCs	Bronchial epithelial cells, macrophage, neutrophils, eosinophils, cardiomyocytes, hypertrophic adipocytes	[9,11]
	IX		Snail venom					[7]
	X		Human spleen/thymus/leukocyte	14		High activity toward PCs	Bronchoalveolar lavage fluid of asthmatic patients, airway epithelium, macrophages, smooth muscle cells, adrenal glands, pancreatic β cells, gut epithelium, sperm acrosome, hair follicles	[9]
	XI	A, B	Green rice shoots	13				[12]
	XII	A, B	Human/murine	19			Hepatocytes	[9]
	XII		Parvovirus	<10				[12]
	XIV		Symbiotic fungus/Streptomyces	13–19				[12]
cPLA2	IV	A, B, C, D, E, F	Human macrophage/pancreas/liver/brain/heart/skeletal muscle Murine placenta/heart/thyroid/stomach/testis/liver cells, neuronal cells	60–144	Ser/Asp Ca²⁺ is required for membrane binding and activation	High specificity for PC, PE containing arachidonic acid at sn-2 position	Intracellularly localized in endoplasmic reticulum, Golgi complexes in epithelial cells	[6,13]
iPLA2	VI	A, B, C, D, E, F	Human/murine	84–90	Ser/Asp Ca²⁺ is not required for catalysis	Phospholipase. Lysophospholipase activity on PL and lyso-PL, transacylase, acyl-CoA thioesterase activity	Group VI-A localizes on mitochondrial membrane and group VI-B on mitochondria and peroxisomes; group VI-C is expressed in neurons and localized on ER and Golgi body; groups VI-D, VI-E and VI-F are localized in adipose tissues	[6,13]
Lp-PLA2 (Lipoprotein- associated PLA2)	VII	A, B	Human, porcine, murine, bovine	40–45	Ser/His/Asp Ca²⁺ is not required for catalysis	Groups VII and VIII hydrolyze the acetyl group from sn-2 position of PAF and generate lyso-PAF and acetate. Group VII-A prefers PC with a shorter chain at sn-2 position	Group VII-A is secreted extracellularly by macrophages, monocyte, mast cells and T-cells. These are also associated with LDL and HDL in plasma; group VII-B is intracellularly expressed in epithelial cells of the kidney, intestine and hepatocytes. They are also overexpressed in neurons; group VIII is intracellularly expressed in brain cells	[6,14]
Lp-PLA2 (Lipoprotein- associated PLA2)	VIII	A, B	Human	26–40	Ser/His/Asp Ca²⁺ is not required for catalysis			[6,14]
LPLA2 (Lysosomal PLA2)	XV		Human, murine, bovine	45	Ser/His/Asp Ca²⁺ is not required for catalysis	LPLA2 is specific towards PC and PE. They hydrolyze the acyl chain at both sn-1 and sn-2 positions of PC and PE with a preference for sn-2 position	Highly expressed in alveolar macrophages; localized in lysosomes	[15]
Ad-PLA2 (Adipose tissue specific PLA2)	XVI		Human, mouse	18	Cys/His/His Ca²⁺ is not required for catalysis		Ubiquitously expressed throughout the body. Highly expressed in adipose tissue.	[6,16]