Minibody

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(No Transcript)
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introduction
Genetic engineering is a widely used strategy to
produce a variety of defined antibody fragments
and novel proteins such as fusion proteins or
immune-toxins. A useful strategy is to produce
scFvs, which is composed of the variable regions
of the immunoglobulin heavy and light chain,
covalently fused by a peptide linker. These small
proteins usually maintain specificity and
affinity for antigen in a single polypeptide and
enable to offer a convenient building block for
larger, antigen-specific molecules.
Nevertheless, on account of the small size of
scFvs, they have limited applications as
tumor-targeting agents in vivo, usually
exhibiting very rapid clearance from the
circulation in animal models. In order to get
optimal tumor targeting, biodistribution, and
clearance characteristics, antibody fragments of
intermediate molecular weight are able to be
developed to have the proper combinations of high
tumor uptake and quick clearance from normal
tissues.
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Minibody
Minibody is composed of a pair of single-chain Fv
fragments which are linked via CH3 domains, and
Fvs with distinct specificity, which paired to
the former part through heterodimerization
process. To promote the heterodimerization
efficiency, single-residue mutations can be
introduced into each CH3 domains to achieve the
knobs and holes approach. Far more than that,
additional cysteine residues can also be
introduced into CH3 domains to stabilize the
bispecific minibody structure.
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With the addition of this extra binding domain,
the avidity of Tribi minibody is significantly
higher than that of the bispecific minibody.
Thus, even at a lower concentration, Tribi
minibody is still able to perform a stronger
cytotoxicity than the corresponding bispecific
minibody.
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Thank you
Reference https//www.creative-biolabs.com/bsab/m
inibody-generation-service.htm