CHM361H5 Lecture Notes - Lecture 10: Arginine, Alpha Helix, Threonine
Document Summary
Turns and loops connect helices and b-strands. Helices and b-strands extend the protein chain along one dimemsnion. Oritentations of adjacent peptide planes differs for different secondary structures. Right-handed coiled conformation; looks like a spring. Each turn of helix accommodates 3. 6 residues. Each reside extends 1. 5 along helix axis. Distance between 1 point and the recurring point. It requires you to go one turn. H-bonds b/w each backbone c=o of residue i and backbone n-h of residue i+4. I. e. from c=o of residue 1 to n-h residue 5. We have c=o residue 2 to n-h residue 6. Unsatisfied h-bonds at n and c termini. Helix capping residues provide h-bond partners through side chains. 4 n-h in n-terminus and 4 c=o in c terminus are not h-bonded. The side chains that can overcome this unsatisfied h-bonds at n and c terminus would be polar, acidic, & basic side chains. Aspartic acid, glutamic acid, lysine, histidine, arginine, serine, threonine,
