A small bispecific protein selected for orthogonal affinity purification
2010 (English)In: BIOTECHNOL J, ISSN 1860-6768, Vol. 5, no 6, 605-617 p.Article in journal (Refereed) Published
A novel protein domain with dual affinity has been created by randomization and selection. The small alkali-stabilized albumin-binding domain (ABD(star)), used as scaffold to construct the library, has affinity to human serum albumin (HSA) and is constituted of 46 amino acids of which 11 were randomized. To achieve a dual binder, the binding site of the inherent HSA affinity was untouched and the randomization was made on the opposite side of the molecule. Despite its small size and randomization of almost a quarter of its amino acids, a bifunctional molecule, ABDz1, with ability to bind to both HSA and the Z(2) domain/protein A was successfully selected using phage display. Moreover, the newly selected variant showed improved affinity for HSA compared to the parental molecule. This novel protein domain has been characterized regarding secondary structure and affinity to the two different ligands. The possibility for affinity purification on two different matrices has been investigated using the two ligands, the HSA matrix and the protein A-based, MabSelect SuRe matrix, and the new protein domain was purified to homogeneity. Furthermore, gene fusions between the new domain and three different target proteins with different characteristics were made. To take advantage of both affinities, a purification strategy referred to as orthogonal affinity purification using two different matrices was created. Successful purification of all three versions was efficiently carried out using this strategy.
Place, publisher, year, edition, pages
2010. Vol. 5, no 6, 605-617 p.
Albumin binding domain, Bispecific binder, Orthogonal purification, Phage display, Z domain
Biochemistry and Molecular Biology
IdentifiersURN: urn:nbn:se:kth:diva-27283DOI: 10.1002/biot.201000041ISI: 000278969600009PubMedID: 20518064OAI: oai:DiVA.org:kth-27283DiVA: diva2:377560
QC 201012142010-12-142010-12-092012-11-22Bibliographically approved