Sandbox 14
From Proteopedia
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Catalytic Triad | Catalytic Triad | ||
| - | + | The active site of trypsin is composed of a catalytic triad-His57,Asp102 and Ser 195. Each of these groups has a specific role to play in the hydrolysis of peptide bonds. These groups are held together by hydrogen bond interactions. Ser 195 is responsible for the attack of the carbonyl groups of the peptide bond to be hydrolyzed. It does this using the oxygen of its hydroxide group. It leaves the attacked carbonyl group with a tetrahedral structure and a negatively charged oxygen. The negatively charged tetrahedral intermediate collapse to form an acyl-enzyme complex. This step is aided by the transfer of protons from the amino acid group, histidine (His 57) to the amino group of the substrate. The amino group is then free to depart. Water H20 hydrolyses the bond between the carbonyl group of the substrate and the oxygen of Ser 195. The substrate is cleaved and the catalytic triad is regenerated. | |
Insert Picture | Insert Picture | ||
The mechanism outlined for the hydrolysis of peptide bonds, including the presence of the catalytic triad, is applicable to both bovine and rat trypsin. | The mechanism outlined for the hydrolysis of peptide bonds, including the presence of the catalytic triad, is applicable to both bovine and rat trypsin. | ||
Revision as of 00:49, 24 June 2010
Please do NOT make changes to this sandbox. Sandboxes 10-30 are currently reserved by Prof. Sheila Jaswal at Amherst College.
Trypsin
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Trypsin Trypsin is a serine protease responsible for the hydrolysis of proteins. This process is biologically applicable in the process of digestion. Unlike other studied proteins such as αLytic Protease and Streptomyces griseus SGPB trypsin exists in a thermodynamically stable state. Trypsin, like other serine proteases, is very specific in its reaction. It cleaves at peptide bonds located after residues with positive side chains, namely, arginine and lysine.
Catalytic Triad
The active site of trypsin is composed of a catalytic triad-His57,Asp102 and Ser 195. Each of these groups has a specific role to play in the hydrolysis of peptide bonds. These groups are held together by hydrogen bond interactions. Ser 195 is responsible for the attack of the carbonyl groups of the peptide bond to be hydrolyzed. It does this using the oxygen of its hydroxide group. It leaves the attacked carbonyl group with a tetrahedral structure and a negatively charged oxygen. The negatively charged tetrahedral intermediate collapse to form an acyl-enzyme complex. This step is aided by the transfer of protons from the amino acid group, histidine (His 57) to the amino group of the substrate. The amino group is then free to depart. Water H20 hydrolyses the bond between the carbonyl group of the substrate and the oxygen of Ser 195. The substrate is cleaved and the catalytic triad is regenerated. Insert Picture
The mechanism outlined for the hydrolysis of peptide bonds, including the presence of the catalytic triad, is applicable to both bovine and rat trypsin.
