BCHS 3304 Lecture Notes - Lecture 13: Protoporphyrin Ix, Porphyrin, Iron(Iii) Oxide
8 Oct 2016
School
Department
Course
Professor
Document Summary
Myoglobin: red blood pigment, 1st protein to be crystallized 1849, 1st to have mass measured, studied by ultracentrifugation, associate with physiological function, point mutation can cause problems, x ray structures solved. Hemoglobin: has 4 heme groups, and thus 4 oxygen binding sites. Co, h2s, no gases compete with oxygen to bind: function. Transports oxygen to tissues from the lungs. Oxygen diffusion is too poor to work alone in larger animals. Alternative transporters: hemocyanin, hemoerythrin: the subunits independently compete for oxygen to bind. When one binds that increases binding affinity. When one molecule binds, the rest bind; when one is released the rest are released cooperativity: structure: Alpha and beta monomers related by 2 fold symmetry. When one oxygen binds change conformation to increase affinity. Fe is 0. 6 angstrom out of the heme plane. Change in quaternary structure: the c terminal residues change interactions, bohr effect: influence of ph on affinity. Higher ph ~ tighter binding of oxygen to hemoglobin.
