L07 Chem 481 Lecture Notes - Lecture 30: Monosaccharide, Trisaccharide, Oxyanion Hole
13 Dec 2016
School
Department
Course
Professor
Document Summary
The active-site zn2+ stabilizes negative charge on the oxygen atom of acetaldehyde, leading to an induced partial positive charge on the carbonyl c. Roh from ser, thr, tyr; rsh from cys; rnh3. Induced fit model: lock and key model was the early accepted model. Active site of enzyme fits the substrate as a lock does a key. But the ultimate purpose is to convert the substrate to products, rapid reaction is a priority, not completely binding the substrate (but still must be able to bind: the induced fit model is more accurate. Both enzyme and substrate are distorted on binding. The binding of glucose to hexokinase induces a significant conformational change in the enzyme (a single polypeptide chain with 2 major domains) Other conformations that each can sample through dynamic motions are on smaller scale, rate of conformational change between intermediates shown by black arrows: can have different preferred conformations that differ slightly in different parts of the reaction.
