Peripheral proteins vary considerably in shape and size and do not have a distinct structure. However, they do have a few characteristic features that make them identifiable as peripheral proteins.
Peripheral proteins have unique amino acid sequences that draw the proteins to the membrane surface where they congregate. This ensures that they are in the correct place to perform their designated function. Without the specific amino acid sequences, these proteins would be unable to adhere to the membrane surface and would instead be distributed evenly throughout the cytoplasm, where they would be regular proteins and not peripheral proteins.
The absence of a hydrophobic region of amino acids is another distinguishing feature in the structure of peripheral proteins. Instead, these membrane proteins have numerous hydrophilic amino acids exposed on their surface, which prevents them from getting drawn into the cell membrane.