Lecture 4 Flashcards
What is the catalytic triad for chymotrypsin?
Aspartate 102
Histidine 57
Serine 195
What is the function of Asp102 in the chymotrypsin catalytic triad?
It stabilizes the charge on His 57
What is the function of the oxyanion hole in chymotrypsin?
Stablizes the tetrahedral TS with h bonds
Why doesn’t chymotrypsin digest itself?
Would eventually but the reaction is occurring amazingly slowly
How is chymotrypsin activated?
Chymotrypsinogen is an inactive zymogen which is partially proteolyzed removing residues 1-15 and 147-148
What is subtilisn?
A serine protease used to investigate the catalytic triad
How does hexokinase prevent uncoupled ATP hydrolysis?
The Km for ATP hydrolysis is 10000x lower than for glucose despite similar reactivity, due to the enzyme’s reduced fit for glucose.
What does Lysozyme do?
Hydrolyses polysaccharides in the cell wall
What are the two mechanisms proposed for lysozyme function?
Carbonium ion mechanism
Vocadlo et al mechanism
