BME 20100 Lecture Notes - Lecture 6: Lactate Dehydrogenase, Tight Binding, Competitive Inhibition

• School: Purdue University
• Department: Biomedical Engineering
• Course: BME 20100
• Professor: Harbin

Document Summary

Differ in aa sequence but are able to catalyze same reaction. Differ in structure, km, vmax, and regulatory properties. Major control through binding of small molecules. Dissociates slowly or not at all from enzyme. Tight binding to e, covalent or noncovalent. Bind free e and prevent s from binding. Insight to mechanisms that promote catalytic activity. Show ways metabolic activity controlled in vivo. Use as therapeutic agents to block metabolic pathways. Can form es or ei but not esi. Decrease rate of catalysis by decreasing proportion of es complexes. Can be relieved by increasing s concentration. E. g. methotrexate binds 1000 times as tightly as s and inhibits nucleotide base synthesis. No change in vmax, increase in km. Inhibitors only bind to es, does not affect substrate binding. Inhibitor binding site is only created once es formed. Cannot be overcome by adding more substrate. I and s can bind to form esi.