Biopanning
Encyclopedia
Biopanning is an affinity selection technique which selects for peptides
that bind to a given target
. All peptide sequences obtained from biopanning using combinatorial peptide libraries have been stored in a special database with the name MimoDB , which is freely available. This technique is often used for the selection of antibodies
too.
Biopanning involves 4 major steps for peptide selection . The first step is to have phage display
libraries prepared. This involves inserting foreign desired gene
segments into a region of the bacteriophage
genome, so that the peptide product will be displayed on the surface of the bacteriophage viron. The most often used are genes pIII or pVIII of bacteriophage M13 .
Next step is the capturing step. It involves conjugating the phage library to the desired target. This procedure is termed panning. It utilizes the binding interactions so that only specific peptides presented by bacteriophage are bound to the target. For example, selecting antibody presented by bacteriophage with coated antigen
in microtiter plates.
The washing step comes after the capturing step to wash away the unbound phages from solid surface. Only the bound phages with strong affinity are kept. The final step involves the elution step where the bound phages are eluted though changing of pH.
The end result is the peptides produced by bacteriophage are specific. The resulting filamentous phages can infect Gram negative
bacteria once again to produce phage libraries. The cycle can occur many times resulting with strong affinity binding peptides to the target.
Peptide
Peptides are short polymers of amino acid monomers linked by peptide bonds. They are distinguished from proteins on the basis of size, typically containing less than 50 monomer units. The shortest peptides are dipeptides, consisting of two amino acids joined by a single peptide bond...
that bind to a given target
Biological target
A biological target is a biopolymer such as a protein or nucleic acid whose activity can be modified by an external stimulus. The definition is context-dependent and can refer to the biological target of a pharmacologically active drug compound, or the receptor target of a hormone . The...
. All peptide sequences obtained from biopanning using combinatorial peptide libraries have been stored in a special database with the name MimoDB , which is freely available. This technique is often used for the selection of antibodies
Antibody
An antibody, also known as an immunoglobulin, is a large Y-shaped protein used by the immune system to identify and neutralize foreign objects such as bacteria and viruses. The antibody recognizes a unique part of the foreign target, termed an antigen...
too.
Biopanning involves 4 major steps for peptide selection . The first step is to have phage display
Phage display
Phage display is a method for the study of protein–protein, protein–peptide, and protein–DNA interactions that uses bacteriophages to connect proteins with the genetic information that encodes them. Phage Display was originally invented by George P...
libraries prepared. This involves inserting foreign desired gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
segments into a region of the bacteriophage
Bacteriophage
A bacteriophage is any one of a number of viruses that infect bacteria. They do this by injecting genetic material, which they carry enclosed in an outer protein capsid...
genome, so that the peptide product will be displayed on the surface of the bacteriophage viron. The most often used are genes pIII or pVIII of bacteriophage M13 .
Next step is the capturing step. It involves conjugating the phage library to the desired target. This procedure is termed panning. It utilizes the binding interactions so that only specific peptides presented by bacteriophage are bound to the target. For example, selecting antibody presented by bacteriophage with coated antigen
Antigen
An antigen is a foreign molecule that, when introduced into the body, triggers the production of an antibody by the immune system. The immune system will then kill or neutralize the antigen that is recognized as a foreign and potentially harmful invader. These invaders can be molecules such as...
in microtiter plates.
The washing step comes after the capturing step to wash away the unbound phages from solid surface. Only the bound phages with strong affinity are kept. The final step involves the elution step where the bound phages are eluted though changing of pH.
The end result is the peptides produced by bacteriophage are specific. The resulting filamentous phages can infect Gram negative
Gram-negative
Gram-negative bacteria are bacteria that do not retain crystal violet dye in the Gram staining protocol. In a Gram stain test, a counterstain is added after the crystal violet, coloring all Gram-negative bacteria with a red or pink color...
bacteria once again to produce phage libraries. The cycle can occur many times resulting with strong affinity binding peptides to the target.