Albumin-Binding Nanobody Sequence for Stable Half-Life Extension

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Solution Overview

Problem

Existing Nanobodies against human serum albumin, such as Alb-8, exhibit low expression levels and stability issues, particularly for VHH-1 type Nanobodies with multiple disulphide bridges, limiting their effectiveness in extending the half-life of therapeutic moieties.

Innovation Solution

The use of an improved Nanobody, referred to as Alb-23, which has specific amino acid sequence variations, enhances stability and expression levels, particularly for VHH-1 type Nanobodies, thereby increasing the half-life of therapeutic proteins and polypeptides.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of stationary object

If existing Nanobodies against human serum albumin (such as Alb-8) are used to extend the half-life of therapeutic moieties, then the half-life extension function is achieved, but the expression levels are low and stability issues occur

Engineering Contradiction:
Improvehalf-life of therapeutic moietiesVSAvoidstability and expression levels
Core Design Contradiction:
Duration of action of stationary objectVSReliability

Solution Approach 1:

The patent applies parameter changes by modifying the amino acid sequence of the Nanobody against human serum albumin. Specifically, the sequence of Alb-8 was optimized to create Alb-23, with changes including substitution of amino acids at positions 16, 44, 45, 74-76, and 83, as well as adjustments to CDR regions. These sequence parameter changes result in improved thermal stability (higher Tm), reduced dimer formation, and significantly higher expression levels while maintaining the half-life extension function.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If VHH-1 type Nanobodies with multiple disulphide bridges are used, then therapeutic function is achieved, but expression levels and stability are significantly reduced

Engineering Contradiction:
Improvetherapeutic functionVSAvoidexpression levels
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent applies parameter changes by optimizing the albumin-binding Nanobody sequence to be compatible with VHH-1 type Nanobodies containing multiple disulphide bridges. The Alb-23 sequence was specifically designed with modifications at critical positions (16, 44, 45, 74-76, 83) and in CDR regions to improve expression levels and stability while maintaining the ability to bind human serum albumin and extend half-life, thereby enabling successful expression of complex multi-disulphide bridge constructs.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3466972B1Serum albumin binding proteins
Publication Date: 2026.03.04 ABLYNX NV
  • EP3466972B1 patent drawingFigure 1
  • EP3466972B1 patent drawingFigure 2
  • EP3466972B1 patent drawingFigure 3

AI summary

The present invention relates to amino acid sequences that are capable of binding to serum albumin; to proteins and polypeptides comprising or essentially consisting of such amino acid sequences; to nucleic acids that encode such amino acid sequences, proteins or polypeptides; to compositions, and in particular pharmaceutical compositions, that comprise such amino acid sequences, proteins and polypeptides; and to uses of such amino acid sequences, proteins and polypeptides.