BCH210H1 Lecture Notes - Lecture 4: Beta Sheet, Alanine, Alpha Helix

• School: UTSG
• Department: Biochemistry
• Course: BCH210H1
• Professor: Stavroula Andreopoulos

Document Summary

Ramachandran plot of all residues: later plot with more protein structures involved, same results as the original plot, will all amino acids have the same distribution on the plot? not always. Ramachandran plot of alanine residues in proteins: alanine in 3d structures can exist in a helix or beta sheet, hydrophobic with a methyl side chain mid-range. Ramachandran plot of glycine residues: glycine residues are quite different, small amino acid reverse turns (that"s why its dark on the right-middle useful for. Reverse (beta) turns: stabilized by h-bonds between hydrogen on the amino group of residue i+2 and oxygen on carbonyl group of residue i+1 different, type i and type ii conformational states that both exist in nature. Ramachandran plot of turn residues: type i i+1 residue in alpha helical conformation i+2 is close to helical region but not perfect, type ii i+1 is in beta-strand conformation.