Molecular display

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Molecular display is a biochemical technique that allows proteins and peptides to be screened and evolved for binding properties ( affinity ) or catalytic activity . For this purpose, members of a protein library are presented on a macromolecular carrier ( in vitro molecular display) or on organismic systems (cells, viruses) ( in vivo molecular display). The coupling of genotype and phenotype is essential in all molecular display systems , i.e. That is, the protein to be screened is coupled covalently or non-covalently by compartmentalization with the associated genetic information.

species

The following types of molecular display have been described so far:

in vitro molecular display:

in vivo molecular display:

procedure

The process differs depending on the type of system used. However, there are common characteristic steps in molecular display:

  1. The production of a molecular library: For the systems presented so far, DNA is initially the carrier of information. The DNA library is transcribed in vitro or in vivo into an RNA library and subsequently translated into a protein library. The individual members of the protein library are linked to the genetic information in the form of DNA or RNA via i) covalent or ii) non-covalent bonds or iii) by compartmentalization. In some systems, molecular carriers are used, which enable the molecule to be screened to be efficiently presented on the surface of the compartment; they thus serve as a bridge or frame.
  2. The protein library is screened for one property: Screenings for binding properties such as affinity and avidity as well as catalytic activity have been described. Most display systems aim at affinity maturation . Molecules that have the desired property to a high degree are selectively enriched (English panning ).
  3. The genetic information is isolated and amplified: a further expansion of the diversity of the original library by mutagenesis , for example faulty PCR , can be incorporated. This means that the genetic information is available for another round of panning in order to further enrich or evolve protein with the desired properties.

After completing a few rounds of panning, the proteins are analyzed on a single clone basis for their desired properties. With molecular display techniques it is possible to generate antibodies with affinities in the femto molar range.

Individual evidence

  1. ↑ Anna Sergeeva, Mikhail G. Kolonin, Jeffrey J. Molldrem, Renata Pasqualini, Wadih Arap: Display technologies: Application for the discovery of drug and gene delivery agents . In: Advanced Drug Delivery Reviews . tape 58 , no. 15 , December 30, 2006, pp. 1622–1654 , doi : 10.1016 / j.addr.2006.09.018 , PMID 17123658 .