Protein–protein interaction screening refers to the identification of

Protein–protein interaction Protein–protein interactions (PPIs) are physical contacts of high specificity established between two or more protein molecules as a result of biochemical events steered by interactions that include electrostatic forces, hydrogen bonding and th ...

with

high-throughput screening High-throughput screening (HTS) is a method for scientific experimentation especially used in drug discovery and relevant to the fields of biology, materials science and chemistry. Using robotics, data processing/control software, liquid handlin ...

methods such as computer- and/or robot-assisted plate reading, flow cytometry analyzing. The interactions between proteins are central to virtually every process in a living cell. Information about these interactions improves understanding of diseases and can provide the basis for new therapeutic approaches.

Methods to screen protein–protein interactions

Though there are many methods to detect protein–protein interactions, the majority of these methods—such as co-immunoprecipitation,

fluorescence resonance energy transfer Fluorescence is the emission of light by a substance that has absorbed light or other electromagnetic radiation. It is a form of luminescence. In most cases, the emitted light has a longer wavelength, and therefore a lower photon energy, tha ...

(FRET) and

dual polarisation interferometry Dual-polarization interferometry (DPI) is an analytical technique that probes molecular layers adsorbed to the surface of a waveguide using the evanescent wave of a laser beam. It is used to measure the conformational change in proteins, or othe ...

—are not screening approaches.

''Ex vivo'' or ''in vivo'' methods

Methods that screen protein–protein interactions in the living cells.

Bimolecular fluorescence complementation Bimolecular fluorescence complementation (also known as BiFC) is a technology typically used to validate protein interactions. It is based on the association of fluorescent protein fragments that are attached to components of the same macromolec ...

(BiFC) is a technique for observing the interactions of proteins. Combining it with other new techniques, dual expression recombinase based ( DERB) methods can enable the screening of protein–protein interactions and their modulators. The

yeast two-hybrid Two-hybrid screening (originally known as yeast two-hybrid system or Y2H) is a molecular biology technique used to discover protein–protein interactions (PPIs) and protein–DNA interactions by testing for physical interactions (such as bindi ...

screen investigates the interaction between artificial fusion proteins inside the nucleus of yeast. This approach can identify the binding partners of a protein without bias. However, the method has a notoriously high false-positive rate, which makes it necessary to verify the identified interactions by co-immunoprecipitation.

''In-vitro'' methods

The

tandem affinity purification Tandem affinity purification (TAP) is an immunoprecipitation-based purification technique for studying protein–protein interactions. The goal is to extract from a cell only the protein of interest, in complex with any other proteins it interacted ...

(TAP) method allows the high-throughput identification of proteins interactions. In contrast with the Y2H approach, the accuracy of the method can be compared to those of small-scale experiments (Collins et al., 2007) and the interactions are detected within the correct cellular environment as by co-immunoprecipitation. However, the TAP tag method requires two successive steps of protein purification, and thus can not readily detect transient protein–protein interactions. Recent genome-wide TAP experiments were performed by Krogan et al., 2006, and Gavin et al., 2006, providing updated protein interaction data for yeast organisms.

Chemical crosslinking In chemistry and biology a cross-link is a bond or a short sequence of bonds that links one polymer chain to another. These links may take the form of covalent bonds or ionic bonds and the polymers can be either synthetic polymers or natural ...

is often used to "fix" protein interactions in place before trying to isolate/identify interacting proteins. Common crosslinkers for this application include the non-cleavable HS-estercrosslinker, 'bis''-sulfosuccinimidyl suberate(BS3); a cleavable version of BS3, ithiobis(sulfosuccinimidyl propionate)DTSSP); and the midoestercrosslinker imethyl dithiobispropionimidate(DTBP) that is popular for fixing interactions in

ChIP Chromatin immunoprecipitation (ChIP) is a type of immunoprecipitation experimental technique used to investigate the interaction between proteins and DNA in the cell. It aims to determine whether specific proteins are associated with specific genomi ...

assays.

References

External links

HPRD Human Protein Reference Database
a (manually) curated database of human protein information with visualization tools
IntAct Interaction Database
a public repository for manually curated molecular interaction data from the literature
DIP Database of Interacting Proteins
a manual and automatic catalog of experimentally determined interactions between proteins
MIPS Mammalian Protein–Protein Interaction Database
the MIPS mammalian protein–protein interaction database {{DEFAULTSORT:Protein-Protein Interaction Screening Signal transduction Biochemistry methods Proteomics