Topic 3 Protein Structure

Figure 3.1: Levels of Protein Structure

Figure 3.1 displays several levels of protein structure.

The primary structure of a protein is its sequence of amino acids.

The secondary structure of a protein refers to its basic patterns of hydrogen bonding. In other words, the secondary structure is concerned with the three-dimensional structures formed via the side chain’s intermolecular interactions (e.g., \(\alpha\)-helices and \(\beta\)-sheets).

The tertiary structure of a protein is the overall three-dimensional shape of the protein. In proteins, this level of structure is also roughly described as a type of protein fold.

The quaternary structure deals with the interactions between multiple polymer chains of a protein (e.g., the structure of a multi-chain assembly).