Identification of 491 proteins in the tear fluid proteome reveals a large number of proteases and protease inhibitors

Table 1 Hydrolases identified in tear fluid

Hydrolase activity	Gene symbol	Biological process
Leukotriene A-4 hydrolase	LTA4H	1,2
Matrix metalloproteinase 8*	MMP8	1,3
Matrix metalloproteinase 9*	MMP9	1,3
Myeloblastin^†	PRTN3	3
Apolipoprotein B	APOBEC3C	4
Azurocidin^†	AZU1	4
Dipeptidylpeptidase IV	DPP4	4
Leukocyte elastase*	ELA2	4
Haptoglobin*	HP	4
Lactotransferrin*	LTF	4,5
Lysozyme C*	LYZ	4
Eosinophil cationic protein*	RNASE3	4,9
Adipocyte-derived leucine aminopeptidase^†	ARTS-1	5
Zinc-alpha-2-glycoprotein*	AZGP1	5
Complement factor B^†	BF	5
Ubiquitin thiolesterase protein^†	OTUB1	5
Palmitoyl-protein thioesterase 1	PPT1	6
Plasminogen*	PLG	7
Aminopeptidase N	ANPEP	8
Acid phosphatase, prostate^†	ACPP	10
Chitinase 3-like protein 2^†	CHI3L2	11
Cytosolic nonspecific dipeptidase^†	CNDP2	1
Cathepsin B*	CTSB	1
Cathepsin D	CTSD	1
Cathepsin G	CTSG	1
Cathepsin Z	CTSZ	1
Prostasin^†	PRSS8	1
Aminopeptidase B^†	RNPEP	1
Tissue alpha-L-fucosidase	FUCA1	12
Beta-mannosidase*	MANBA	13
Alpha-N-acetylglucosaminidase*	NAGLU	12
Neuraminidase	NEU1	12

*The protein has already described in the tear fluid. ^†The protein is classified as an extracellular protein. 1, Proteolysis; 2, inflammatory response; 3, extracellular matrix degradation; 4, defense response; 5, immune response; 6, visual perception; 7, blood coagulation; 8, angiogenesis; 9, nucleotide metabolism; 10, regulation of cell proliferation; 11, chitin catabolism; 12, carbohydrate metabolism; 13, protein modification; 14, central nervous system development; 15, signal transduction.

ISSN: 1474-760X