BIO SCI 98 Lecture Notes - Lecture 1: Peptide, Disulfide, Threonine
Document Summary
Stabilizing interactions: hydrophobic interactions are always in the interior, maximize the number of h-bonds and ionic interactions, sometimes disulfide bridges. Ramachandran plot: (less bulky = more mobility; branched aa"s have smaller ranges) Darker sites = conformations are fully allowed and not hindered. Medium blue = less likely to have those comfortations. Light blue = allowed only with bond flexing (ex. gylcine has the broadest range vs. proline with the cyclic form) Structure of proteins: primary: sequence of aas determines final structure (peptide/disulfide bonds, secondary: stable arrangements of aas (hydrogen bonds in a-helix, b sheets, b turns) every hydrogen is bonded with every oxygen (a-carbonyl oxygen + a-amino hydrogen, a-helices: Three residues should be complementary (+/- or hydrophobic) Long stretches of similarly charged aa (or bulky aa"s like asparagine and threonine) are destabilizing. Charge @ amino end / + charge @ carboxyl end.
