LIFESCI 3 Chapter Notes - Chapter 5.1: Dna Binding Site, Binding Constant, Cooperative Binding
Document Summary
A protein bound to another macromolecule can alter structure and/or function. Reversible binding of proteins to other molecules follows defined principles. Ligand: any kind of molecule bound by a given protein. Protein-ligand interactions allow organisms to respond rapidly and reversibly to changing environmental and metabolic circumstances. Binding site: site on the protein where a ligand binds. Complementary to ligand in size, shape, charge, and hydrophobicity or hydrophilicity. Protein discriminates among molecules and selectively binds to one or a few. Protein may have separate binding sites for multiple different ligands. Can be subtle (molecular vibrations or small amino acid movement) Or dramatic (major segments of protein move) Many protein ligand interactions require an induced fit. Induced fit: conformational change in protein alters a binding site so it becomes more complementary to the ligand. Conformational change in one subunit can affect conformation of other subunits.
