Biologic Evaluation of a Heterodimeric HER2-Albumin Targeted Affibody Molecule Produced by Chemo-Enzymatic Peptide Synthesis.

Targeted molecular radiation therapy is a promising emerging treatment modality in oncology, and peptide synthesis may shorten the time to reach the clinical stage. In this study, we have explored Chemo-Enzymatic Peptide Synthesis, or CEPS, as a new means of producing a therapeutic HER2 targeted Affibody molecule, comprising a C-terminal albumin binding domain (ABD) for half-life extension and a total length of 108 amino acids. In addition, a DOTA moiety could be incorporated at N-terminus directly during the synthesis step and subsequently utilized for site-specific radiolabeling with the therapeutic radionuclide Lu.

In Vivo Evaluation and Dosimetry Estimate for a High Affinity Affibody PET Tracer Targeting PD-L1.

Purpose: In vivo imaging of programmed death ligand 1 (PD-L1) during immunotherapy could potentially monitor changing PD-L1 expression and PD-L1 expression heterogeneity within and across tumors. Some protein constructs can be used for same-day positron emission tomography (PET) imaging. Previously, we evaluated the PD-L1-targeting Affibody molecule [F]AlF-NOTA-Z as a PET tracer in a mouse tumor model of human PD-L1 expression.

In Vivo Imaging of the Programmed Death Ligand 1 by F PET.

Programmed death ligand 1 (PD-L1) is an immune regulatory ligand that binds to the T-cell immune check point programmed death 1. Tumor expression of PD-L1 is correlated with immune suppression and poor prognosis. It is also correlated with therapeutic efficacy of programmed death 1 and PD-L1 inhibitors.

Early implementation of QbD in biopharmaceutical development: a practical example.

In drug development, the "onus" of the low R&D efficiency has been put traditionally onto the drug discovery process (i.e., finding the right target or "binding" functionality).

An engineered affibody molecule with pH-dependent binding to FcRn mediates extended circulatory half-life of a fusion protein.

Proteins endocytosed from serum are degraded in the lysosomes. However, serum albumin (SA) and IgG, through its Fc part, bind to the neonatal Fc receptor (FcRn) at low pH in the endosome after endocytosis, and are transported back to the cellular surface, where they are released into the bloodstream, resulting in an extended serum circulation time. Association with Fc or SA has been used to prolong the in vivo half-life of biopharmaceuticals, using the interaction with FcRn to improve treatment regimens.

Site-specific radiometal labeling and improved biodistribution using ABY-027, a novel HER2-targeting affibody molecule-albumin-binding domain fusion protein.

Unlabelled: Because of their better penetration, smaller targeting proteins may be superior to antibodies for radioimmunotherapy of solid tumors. Therefore, Affibody molecules (6.5 kDa) have a potential for being suitable as targeted moiety for radiolabeled therapeutic proteins.

A native chemical ligation approach for combinatorial assembly of affibody molecules.

Affinity molecules labeled with different reporter groups, such as fluorophores or radionuclides, are valuable research tools used in a variety of applications. One class of engineered affinity proteins is Affibody molecules, which are small (6.5 kDa) proteins that can be produced by solid phase peptide synthesis (SPPS), thereby allowing site-specific incorporation of reporter groups during synthesis.

Extending half-life by indirect targeting of the neonatal Fc receptor (FcRn) using a minimal albumin binding domain.

The therapeutic and diagnostic efficiency of engineered small proteins, peptides, and chemical drug candidates is hampered by short in vivo serum half-life. Thus, strategies to tailor their biodistribution and serum persistence are highly needed. An attractive approach is to take advantage of the exceptionally long circulation half-life of serum albumin or IgG, which is attributed to a pH-dependent interaction with the neonatal Fc receptor (FcRn) rescuing these proteins from intracellular degradation.

N-terminal engineering of amyloid-β-binding Affibody molecules yields improved chemical synthesis and higher binding affinity.

The aggregation of amyloid-β (Aβ) peptides is believed to be a major factor in the onset and progression of Alzheimer's disease. Molecules binding with high affinity and selectivity to Aβ-peptides are important tools for investigating the aggregation process. An Aβ-binding Affibody molecule, ZAβ3 , has earlier been selected by phage display and shown to bind Aβ(1-40) with nanomolar affinity and to inhibit Aβ-peptide aggregation.

Crystal structure of the ENT domain of human EMSY.

EMSY is a recently discovered gene encoding a BRCA2-associated protein and is amplified in some sporadic breast and ovarian cancers. The EMSY sequence contains no known domain except for a conserved approximately 100 residue segment at the N terminus. This so-called ENT domain is unique in the human genome, although multiple copies are found in Arabidopsis proteins containing members of the Royal family of chromatin remodelling domains.

Binding of EMSY to HP1beta: implications for recruitment of HP1beta and BS69.

EMSY is a large nuclear protein that binds to the transactivation domain of BRCA2. EMSY contains an approximately 100-residue segment at the amino terminus called the ENT (EMSY N-terminal) domain. Plant proteins containing ENT domains also contain members of the royal family of chromatin-remodelling domains.

Comparison of BRCT domains of BRCA1 and 53BP1: a biophysical analysis.

53BP1 interacts with the DNA-binding core domain of the tumor suppressor p53 and enhances p53-mediated transcriptional activation. The p53-binding region of 53BP1 maps to the C-terminal BRCT domains, which are homologous to those found in the breast cancer protein BRCA1 and in other proteins involved in DNA repair. Here we compare the thermodynamic behavior of the BRCT domains of 53BP1 and BRCA1 and examine their ability to interact with the p53 core domain.