Different combinations of amino acids give different properties to proteins. Therefore, the main feature that should be used in distinguishing proteins from each other is the amino acid sequence of proteins. However, proteins can be distinguished by their size and the biochemical properties as well.
Proteins are made of amino acids that gives them different properties. The different properties of the proteins makes them different from each other.
Proteins can also be differentiated based on their structures. It can be primary, secondary, tertiary or quarternary. The structure of the protein determines its function.
Basically, the type of amino acid found in the protein determines its properties.
