Table 2.

Cysteine protease with their inactivation and activation modes.

Enzyme class	Inactivation mechanism	Activation/Processing
Cysteine protease (Cathepsins and parasitic)	• Steric block of the active site by prodomain	• Generally via auto-activation but some are activated by trans-activation; e.g., cathepsin C and X
		• Disruption of salt bridges, hydrophobic interactions, e.g., falcipain-2 and falcipain-3
		• No conformational change in the mature domain during activation in cathepsin L-like cysteine proteases but cathepsin B-like undergo significant change due to occluding loop
		• Some proteases are involved in trans-activation, i.e., asparaginyl amino-peptidase