BCHS 3304 Lecture Notes - Lecture 9: Coiled Coil, Beta Hairpin, Hairpin Turn
21 Sep 2016
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Document Summary
Proteins that exhibit a twisting beta sheet do so because: they have a chiral l amino acid a twist that distorts the h bonding, not a static structure. Can move and vibrate due to external circumstance. Beta strands can be connected in an antiparallel or parallel manner: antiparallel hairpin turn, parallel cross over loop thingy. Non repetitive regions: make up 50% of globular protein structure, turns: coils, loops, beta bends. There is a type 1 and 2. Fibrous proteins: alpha keratin= a coiled coil. Helical, different spacing from regular alpha helix: 5. 1. Hard keratin has high cys, soft keratin has low cys. Curly hair= more cys residues: tropomyosin= coiled coil, collagen= triple helix. Bones, teeth, cartilage, tendon, ligament, blood vessels, skin matrix. 3 left handed helices one triple right handed coil. Gives stability and strength thru hydrogen bonding. W/o prolyl hydroxylase collagen denatures at 24. Amino acid sequence affects secondary structure: regular structure= alpha helix, beta strands, irregular= coils.
