Clinigal enzymology

Question 1

inidicators

Answer 1

The activities of many enzymes are routinely determined in plasma for diagnositcs in the heart,liver,skeletal muscle, pancreas and other tissues.

Question 2

Aspartyle proteases

Answer 2

One aspartate takes a proton from the water, creating a hydroxide ion. Other aspartate donates a proton to the oxygen of the peptide carbonyl group, one acts as acid, other acts as a base.

Question 3

Metaloproteases

Answer 3

Zn^-2 helps convert water to a hydroxide ion.
AN acid residue helps by taking a proton.

The hydroxide ion then carries out nucleophilic attack.

Question 4

Carboxypeptidase A

Answer 4

Is a metalloprotease.
They are digestive enzymes, secreted in the pancreas.

Mechanic:
Removes hydrophobic amino acid from the C terminus of polypeptides. Broken by hydrolysis.

Question 5

Carboxypeptidase active site

Answer 5

The zinc ion, ZN^-2 is co-ordinated by 2 histidine residues.

Zinc generates a hydroxyl nucleophile from bound water, Glu 270 helps by taking the proton

The hydroxyl group carries out nucleophilic attack on the carbonyl carbon atom.

Forms tetrhedral intermediate which collapses (chymotrypsin)