Lecture Notes: Myoglobin

Introduction

• Comparison to Hemoglobin
  • Both are heme proteins.
  • Serve different functions.

Myoglobin Overview

• Location
  • Found in heart and skeletal muscles.
• Function
  • Acts as an oxygen carrier.
  • Increases oxygen transport rate within muscle cells.
  • Serves as an oxygen reservoir.
  • Crucial during exercise for increased oxygen demand.

Structure of Myoglobin

• Compact Molecule
  • Contains eight alpha helices.
• Alpha Helix Description
  • Secondary structure of amino acids.
  • Contains a nitrogen donating hydrogen to a carbonyl group, forming a spiral.
  • Helices labeled from A to H.
• Amino Acid Composition
  • Interior: Non-polar (hydrophobic) amino acids.
  • Surface: Polar and hydrophobic amino acids.
  • Interior similar to hemoglobin.

Heme Binding in Myoglobin

• Heme Group Stability
  • Proximal histidine: Binds directly to the iron of heme.
  • Distal histidine: Stabilizes the binding of oxygen to iron.

Conclusion

• Preview of next video: Oxygen dissociation curves of myoglobin and hemoglobin.
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