Table 1 Protease-antiprotease interactions

Neutrophil elastase

Serine

Degrades elastin, collagen type IV & laminin

AAT

Inactivates TIMP

SERPINA3

Activates MMP9

SLPI

Cathepsin G

Serine

Degrades elastin, collagen I, II, IV & laminin

SERPINA3

Activates MMP9

SLPI

Proteinase 3

Serine

Degrades elastin & collagen IV

AAT

Activates TNFα

Cathepsin B

Cysteine

Degrades elastin

Cystatin C

Inactivates secretory leukocyte proteinase inhibitor (SLPI)

MMP1

MMP

Degrades collagens I-IV, VII, VIII, X, XI

TIMP1-4

Inactivates AAT

Activates TNFα

MMP9

MMP

Degrades collagen IV, V, X, XIV & elastin

TIMP1-4

Inactivates AAT

Activates TNFα & TGFβ

MMP12

MMP

Degrades collagen I, IV, elastin & fibrillin

TIMP1-4

Inactivates AAT

Activates TNFα