Copurification in a chemical

Chemistry

Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds....

 or biochemical

Biochemistry

Biochemistry, sometimes called biological chemistry, is the study of chemical processes in living organisms, including, but not limited to, living matter. Biochemistry governs all living organisms and living processes...

 context is the physical separation

Separation process

In chemistry and chemical engineering, a separation process, or simply a separation, is any mass transfer process used to convert a mixture of substances into two or more distinct product mixtures, at least one of which is enriched in one or more of the mixture's constituents. In some cases, a...

 by chromatography

Chromatography

Chromatography is the collective term for a set of laboratory techniques for the separation of mixtures....

 or other purification technique of two or more substances of interest from other contaminating

Contamination

Contamination is the presence of a minor and unwanted constituent in material, physical body, natural environment, at a workplace, etc.-Specifics:"Contamination" also has more specific meanings in science:...

 substances. For substances to co-purify usually implies that these substances attract each other to form a non-covalent

Noncovalent bonding

A noncovalent bond is a type of chemical bond, typically between macromolecules, that does not involve the sharing of pairs of electrons, but rather involves more dispersed variations of electromagnetic interactions. The noncovalent bond is the dominant type of bond between supermolecules in...

 complex

Complex (chemistry)

In chemistry, a coordination complex or metal complex, is an atom or ion , bonded to a surrounding array of molecules or anions, that are in turn known as ligands or complexing agents...

 such as in a protein complex

Protein complex

A multiprotein complex is a group of two or more associated polypeptide chains. If the different polypeptide chains contain different protein domain, the resulting multiprotein complex can have multiple catalytic functions...

.

However when fractionating

Fractionation

See also: Fractionated spacecraftFractionation is a separation process in which a certain quantity of a mixture is divided up in a number of smaller quantities in which the composition changes according to a gradient. Fractions are collected based on differences in a specific property of the...

 mixtures, especially mixtures containing large numbers of components (for example a cell lysate), it is possible by chance that some components may copurify even though they don't form complexes. In this context the term copurification is sometimes used to denote when two biochemical activities or some other property are isolated together after purification but it is not certain if the sample has been purified to homogeneity (i.e., contains only one molecular species or one molecular complex). Hence these activities or properties are likely but not guaranteed to reside on the same molecule or in the same molecular complex.

Applications

Copurification procedures, such as co-immunoprecipitation, are commonly used to analyze interactions between proteins. Copurification is one method used to map the interactome

Interactome

Interactome is defined as the whole set of molecular interactions in cells. It is usually displayed as a directed graph. Molecular interactions can occur between molecules belonging to different biochemical families and also within a given family...

of living organisms.