BIO 253 Lecture Notes - Lecture 9: Zymogen, Trypsin, Chymotrypsin
Document Summary
How enzymes are normally inhibited: such as having hemoglobin that have an inhibitor called bpg and inhibitors can also affect a protein that is not an enzyme. Allosteric modulator: binds to the protein and changes the shape and therefore the function of the protein. It can also bind and interact with other subunits such as a holoenzyme (separate polypeptides) Heterotropic interaction: when some other molecule besides the ligand binds to the enzyme. Aspartate catalyzes the first step of the reaction. The product can go back and negatively regulate the reaction and inhibit the first step of the reaction (negative feedback inhibition) Best step to regulate is the first step because regulating it later in the pathway is less efficient. Y axis = initial velocity, x axis = substrate concentration. Allosteric enzymes display a sigmoid and not a hyperbolic curve for the initial velocity versus [s]: K0. 5 = the substrate concentration in which an allosteric modulator is operating at v max.
