BIOC 405 Study Guide - Midterm Guide: Globular Protein, Hydrogen Bond, Myoglobin
Document Summary
Proteins fold in complex ways with variations in phi-psi angles per residue that lead to a particular three-dimensional conformation. In many instances, however, there are stretches of amino acids in a protein with a more regular structure (repeating , angle motif). This conformation is energetically favorable because the main chain c=o group form a hydrogen bond with the nh group of an amino acid four residues distant on the chain. 100 degrees right-handed rotation from residue to residue viewed along the axis. This allows r groups to be pointed away from the helix (more energetically favorable). Hydrogen bonds between: main chain c=o of residue n/the main chain nh of residue n+4. The predicted -helix was confirmed when this protein structure was determined. Myoglobin also contains a heme group which contains an fe(ii) ion. Involves hydrogen bond interactions between the nh and c=o groups in a protein backbone. Unlike -helices that are n+4 local interactions, the h- protein backbone.
