A globular protein is a protein that is globe-like, or rounded in shape, often soluble in aqueous solution. This distinguishes them from fibrous proteins, such as keratin, which may not as soluble. Most globular proteins are enzymes or transporter proteins, whereas fibrous proteins mostly have structural functions.
Nomenclature
The term is old, probably 19th century, predating the discovery of secondary structural motifs, and does not require the kinds of techniques used in modern structural biology. Without knowing the exact structure, the globular nature of proteins can be determined using ultracentrifuges or dynamic light scattering techniques.
Members
Among the most known globular proteins is hemoglobin, a member of the globin protein family. Other globular proteins are the immunoglobulins (IgA, IgD, IgE, IgG and IgM), and alpha, beta and gamma globulins. See protein electrophoresis for more information on the different globulins. Nearly all enzymes with major metabolic functions are globular in shape, as well as many signal transduction proteins.
globulin, any of a large family of proteins of a spherical or globular shape that are widely distributed throughout the plant and animal kingdoms.
The term globulin is a partly procedural one, used in classifying an otherwise diverse group of proteins that are soluble in water or dilute salt solutions.
Other globulins are involved in the transport of a variety of substances, including lipids, hormones, and inorganic ions.
Feeds |
Contact