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

Table 2 Protease inhibitors identified in the tear fluid

Protease inhibitor	Gene symbol	Biological process
Alpha-2-macroglobulin*	A2M
Alpha-2-HS-glycoprotein*	AHSG	2
Alpha-1-microglobulin^†	AMBP	2
Annexin 5	ANXA5	7
Complement C3*	C3	2,5
Complement C4^†	C4A	2,5
Cystatin B	CSTB
Cystatin SN*	CST1
Cystatin SA*	CST2
Cystatin C*	CST3
Cystatin S*	CST4
Inter-alpha-trypsin inhibitor heavy chain H1*	ITIH1	5
Inter-alpha-trypsin inhibitor heavy chain H2^†	ITIH2	5
Inter-alpha-trypsin inhibitor heavy chain H4^†	ITIH4	5
Lipocalin 1*	LCN1	5
Similar to Lipocalin 1
Lipocalin 2	LCN2
Latexin^†	LXN
Prosaposin^†	PSAP
Alpha-1-antitrypsin*	SERPINA1	5
Alpha-1-antichymotrypsin*	SERPINA3	2,5
Leukocyte elastase inhibitor*	SERPINB1	5
Plasminogen activator inhibitor-2^†	SERPINB2	7
Maspin^†	SERPINB5
Placental thrombin inhibitor^†	SERPINB6
Antithrombin-III^†	SERPINC1	7
Pigment epithelium-derived factor*	SERPINF1	8
Plasma protease C1 inhibitor^†	SERPING1	5,7
Neuroserpin	SERPINI1	14
Stratifin^†	SFN	15
Thrombospondin-1^†	THBS1	7
Tissue inhibitor of metalloproteinase 1*	TIMP1	10

*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