Globular protein

A globular protein is one of a common type of protein.
They are one of three types of protein. The others are fibrous and membrane proteins.
Their structure is a result of protein folding. They are made of polypeptide chains folded into a compact sphere shape. 
They are soluble in water because of the hydrophilic ('water-loving') side chains that project from the outside of the molecules. They play an important role in metabolic reactions.
Unlike proteins which only have a structural function, globular proteins can act as:
Globular proteins include myoglobin and hemoglobin.
Globulins.
Globulins are all globular proteins except albumins. They have higher molecular weights than albumins. They are insoluble in pure water but dissolve in dilute salt solutions. 
Some globulins have important function as antibodies, others are responsible for the transport of lipids, iron or copper in the blood.