Proteases

Question 1

Cysteine Proteases

Answer 1

• Requires sulfhydryl active site
• Common examples: Papain, calpain, interleukin-1-b converting enzyme

memorization: Cy Stein was the sulf-hydrylating jewish wrestler, felt the pain.

Question 2

Aspartic Proteases

Answer 2

• Requires aspartate residue active site (pKa 2-4), low pH
• Common examples: pepsin, renin, HIV protease (inhibited by mimicing protein substrate ex: HIV protease drug cocktail

memorization: get in part of the ass

Question 3

Metalloproteases

Answer 3

• MMPs active site requires metal usually Zn2+, sometimes CO2, May need Ca2+ for structure
• Examples: Carboxypeptidase, thermolysin, collagenase, Matrix Metalloproteases, Inhibited by EDTA (chelator)

memorize: ?

Question 4

Serine Proteases

Answer 4

• Requires Asp-Ser-His catalytic triad
• Important for digestion example: Trypsin
• Inhibited by DFP and Serpins (serine protease inhibitors)

memorize: Sarah probably tryped on that asp, sarah didn’t hear it hiss