Serum albumin binding knob domains engineered within a VH framework III bispecific antibody format and as chimeric peptides

Ralph Adams, Callum Joyce, Mikhail Kuravskiy, Katriona Harrison, Zainab Ahdash, Matthew Balmforth, Kelda Chia, Cinzia Marceddu, Matthew Coates, James Snowdon, Emmanuel Goursaud, Karelle Menochet, Jean Van Den Elsen, Richard J. Payne, Alastair Lawson, Anthony Scott-Tucker, Alex Macpherson

Research output: Contribution to journalArticlepeer-review

4 Citations (SciVal)


Background: Serum albumin binding is an established mechanism to extend the serum half-life of antibody fragments and peptides. The cysteine rich knob domains, isolated from bovine antibody ultralong CDRH3, are the smallest single chain antibody fragments described to date and versatile tools for protein engineering.

Methods: Here, we used phage display of bovine immunematerial to derive knob domains against human and rodent serum albumins. These were used to engineer bispecific Fab fragments, by using the framework III loop as a site for knob domain insertion.

Results: By this route, neutralisation of the canonical antigen (TNFa) was retained
but extended pharmacokinetics in-vivo were achieved through albumin binding.
Structural characterisation revealed correct folding of the knob domain and
identified broadly common but non-cross-reactive epitopes. Additionally, we
show that these albumin binding knob domains can be chemically synthesised to
achieve dual IL-17A neutralisation and albumin binding in a single chemical entity.

Conclusions: This study enables antibody and chemical engineering from bovine
immune material, via an accessible discovery platform
Original languageEnglish
Article number1170357
Number of pages15
JournalFrontiers in Immunology
Publication statusPublished - 12 May 2023

Bibliographical note

This work was funded by UCB Biopharma UK.

Data availability statement:
The original contributions presented in the study are included in the article/Supplementary Material. Further inquiries can be directed to the corresponding authors.


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