Carboxypeptidase contains:a)Zn (II) and hydrolyses CO2.b)Mg (II) and h...
Carboxypeptidase is an enzyme that hydrolyzes peptide bonds in proteins and peptides. It is found in the pancreatic juice and intestinal mucosa of animals. The enzyme is classified as a hydrolase, which means it breaks down molecules by adding water. Carboxypeptidase contains a zinc ion (Zn (II)) in its active site, which is essential for its catalytic function.
The mechanism of action of carboxypeptidase involves the binding of the substrate (a peptide or protein molecule) to the active site of the enzyme. The zinc ion acts as a Lewis acid, which means it accepts a pair of electrons from the peptide bond, thereby weakening the bond. This makes it easier for a water molecule to attack the peptide bond and break it, resulting in the release of the carboxyl-terminal amino acid residue.
The specificity of carboxypeptidase for carboxyl-terminal amino acid residues is due to the presence of a negatively charged pocket in the active site of the enzyme. This pocket attracts the positively charged amino group of the carboxyl-terminal amino acid residue, thereby positioning it for catalysis.
In summary, carboxypeptidase is an enzyme that hydrolyzes peptide bonds in proteins and peptides. It contains a zinc ion in its active site and is specific for carboxyl-terminal amino acid residues.