6. Enzyme specificity
Broad Specificity of enzymes
1. eg Chymotrypsin hydrolyses peptide bond (carboxyl group
contributed by phenylalanine, Tyrosine, Tryptophan)
2. Intestinal Phosphatase –hydrolysis of esters of phosphoric acid
7. Broad specificity of Chymotrypsin
Hydrolysis of peptide bonds by Chymotrypsin
• A1—A2-----------------------------A4 ----A5--COOH
• A1—A2-----------------------------A4 ----A5—COOH
• A1—A2-----------------------------A4 ----A5--COOH
• Site of cleavage by chymotrypsin
PHENYLALANINE
TYROSINE
TRYPTOPHAN
11. Applications of Enzyme Specificity
1.Lock & key relationship between the substrate & specific area on
the enzyme
2.Substrate structural features
(a) bonding group or functional group
( b) susceptible bond
Enzyme structural features
(a) positioning site Active site
(b) catalytic site
Mapping of enzyme active site-needed for drug designing
12. Mapping Of Enzyme Active Site
• Substrate of Chymotrypsin =
hydrophobic positioning group +
susceptible acyl bond
• Active site of Chymotrypsin
=positioning group + catalytic site
• Positioning group can be attributed
by hydrophobic /aromatic ring of
amide ,esters ,amino acids ( Phe
,Trp,Tyr )