Editing Protein engineering (section)

=== Multivalent binding ===
{{Main|Polyvalency (chemistry)}}
Multivalent binding can be used to increase the binding specificity and affinity through [[avidity]] effects. Having multiple binding domains in a single biomolecule or complex increases the likelihood of other interactions to occur via individual binding events. Avidity or effective affinity can be much higher than the sum of the individual affinities providing a cost and time-effective tool for targeted binding.<ref>{{Citation|last1=Liu|first1=Cassie J.|title=Engineering Multivalent and Multispecific Protein Therapeutics|date=2014|url=https://doi.org/10.1007/978-1-4471-4372-7_14|work=Engineering in Translational Medicine|pages=365–396|editor-last=Cai|editor-first=Weibo|place=London|publisher=Springer|language=en|doi=10.1007/978-1-4471-4372-7_14|isbn=978-1-4471-4372-7|access-date=2021-12-08|author2-link=Jennifer Cochran|last2=Cochran|first2=Jennifer R.|url-access=subscription}}</ref>

==== Multivalent proteins ====
Multivalent proteins are relatively easy to produce by post-translational modifications or multiplying the protein-coding DNA sequence. The main advantage of multivalent and multispecific proteins is that they can increase the effective affinity for a target of a known protein. In the case of an inhomogeneous target using a combination of proteins resulting in multispecific binding can increase specificity, which has high applicability in protein therapeutics.

The most common example for multivalent binding are the antibodies, and there is extensive research for bispecific antibodies. Applications of bispecific antibodies cover a broad spectrum that includes diagnosis, imaging, prophylaxis, and therapy.<ref>{{Cite journal|last1=Holliger|first1=P.|last2=Prospero|first2=T.|last3=Winter|first3=G.|date=1993-07-15|title="Diabodies": small bivalent and bispecific antibody fragments.|journal=Proceedings of the National Academy of Sciences|language=en|volume=90|issue=14|pages=6444–6448|doi=10.1073/pnas.90.14.6444|issn=0027-8424|pmc=46948|pmid=8341653|bibcode=1993PNAS...90.6444H |doi-access=free }}</ref><ref>{{Cite journal|last1=Brinkmann|first1=Ulrich|last2=Kontermann|first2=Roland E.|date=2017-02-17|title=The making of bispecific antibodies|journal=mAbs|language=en|volume=9|issue=2|pages=182–212|doi=10.1080/19420862.2016.1268307|issn=1942-0862|pmc=5297537|pmid=28071970}}</ref>