Globus hystericus

Globular proteins or spheroproteins are one of the three main types of proteins. They are spherical (globular) in shape and soluble in water, unlike the other two types of proteins, fibrous proteins and membrane proteins. Globular proteins play an essential role in various biological activities, including enzyme catalysis, transport of molecules, and cell signaling.

Structure

Globular proteins have a compact, spherical shape, with their hydrophobic (water-fearing) amino acid residues buried in the core of the protein and their hydrophilic (water-loving) residues exposed on the surface. This structure is stabilized by various types of protein-protein interactions, including hydrogen bonds, ionic bonds, disulfide bonds, and van der Waals forces.

Function

Globular proteins perform a wide range of functions in the cell. Many act as enzymes, catalyzing biochemical reactions. Others are involved in transport of molecules, carrying substances such as oxygen and lipids through the bloodstream. Some globular proteins function in cell signaling, transmitting signals from the cell surface to the interior of the cell.

Examples

Examples of globular proteins include hemoglobin, which transports oxygen in the blood; insulin, a hormone that regulates blood sugar levels; and antibodies, which are part of the immune system's defense against pathogens.

See also

• Protein structure
• Protein folding
• Protein-protein interaction