BIO 253 Lecture Notes - Lecture 8: Histidine, Enolase, Hydrolysis
Document Summary
Active site of chymotrypsin: enzymes have catalytic residues that are important for accelerating the chemical reaction and there are also residues involved in the binding substrate that are usually different than the catalytic residues. Which amino acids serve as catalytic residues: typically the charged amino acids. There is a formation of the binding of substrate to enzyme and the hydrophobic pocket contributes to binding energy and reduces the entropy as well as undergoes desolvation. First, substrate binds to the enzyme and causes a conformational change. The histidine becomes more basic and serves as a nucleophile and will more likely pull of the proton of the serine amino acid by attacking it. The glycine is able to donate the proton to help stabilize the entire negative charge. The peptide bond then breaks apart and allows the carbon to not have 5 bonds and the peptide bond is gone and the intermediate collapses and the peptide bond is broken.
