scholarly journals Comparative Preclinical Evaluation of HER2-Targeting ABD-Fused Affibody® Molecules 177Lu-ABY-271 and 177Lu-ABY-027: Impact of DOTA Position on ABD Domain

Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 839
Author(s):  
Yongsheng Liu ◽  
Anzhelika Vorobyeva ◽  
Tianqi Xu ◽  
Anna Orlova ◽  
Annika Loftenius ◽  
...  
Keyword(s):  
A Priori ◽  
Albumin Binding ◽  
Tumor Uptake ◽  
Site Specific ◽  
Affibody Molecules ◽  
Preclinical Evaluation ◽  
Renal Uptake ◽  
C Terminus ◽  
Minimal Modification ◽  
Structure Properties

Radiolabeled Affibody-based targeting agent 177Lu-ABY-027, a fusion of an anti-HER2 Affibody molecule with albumin binding domain (ABD) site-specifically labeled at the C-terminus, has demonstrated a promising biodistribution profile in mice; binding of the construct to albumin prevents glomerular filtration and significantly reduces renal uptake. In this study, we tested the hypothesis that site-specific positioning of the chelator at helix 1 of ABD, at a maximum distance from the albumin binding site, would further increase the strength of binding to albumin and decrease the renal uptake. The new construct, ABY-271 with DOTA conjugated at the back of ABD, has been labelled with 177Lu. Targeting properties of 177Lu-ABY-271 and 177Lu-ABY-027 were compared directly. 177Lu-ABY-271 specifically accumulated in SKOV-3 xenografts in mice. The tumor uptake of 177Lu-ABY-271 exceeded uptake in any other organ 24 h and later after injection. However, the renal uptake of 177Lu-ABY-271 was two-fold higher than the uptake of 177Lu-ABY-027. Thus, the placement of chelator on helix 1 of ABD does not provide desirable reduction of renal uptake. To conclude, minimal modification of the design of Affibody molecules has a strong effect on biodistribution, which cannot be predicted a priori. This necessitates extensive structure-properties relationship studies to find an optimal design of Affibody-based targeting agents for therapy.

scholarly journals Site-Specific Radioiodination of HER2-Targeting Affibody Molecules using 4-Iodophenethylmaleimide Decreases Renal Uptake of Radioactivity

ChemistryOpen ◽  
2015 ◽  
Vol 4 (2) ◽  
pp. 174-182 ◽  
Author(s):  
Joanna Strand ◽  
Patrik Nordeman ◽  
Hadis Honarvar ◽  
Mohamed Altai ◽  
Anna Orlova ◽  
...  
Keyword(s):  
Site Specific ◽  
Affibody Molecules ◽  
Renal Uptake

On Generalized Vector Space Model in Information Retrieval

1985 ◽  
Vol 8 (2) ◽  
pp. 253-267
Author(s):  
S.K.M. Wong ◽  
Wojciech Ziarko
Keyword(s):  
Information Retrieval ◽  
Vector Space ◽  
A Priori ◽  
Vector Space Model ◽  
Smart System ◽  
Space Model ◽  
Retrieval Systems ◽  
Information Retrieval Systems ◽  
Index Terms ◽  
Minimal Modification

In information retrieval, it is common to model index terms and documents as vectors in a suitably defined vector space. The main difficulty with this approach is that the explicit representation of term vectors is not known a priori. For this reason, the vector space model adopted by Salton for the SMART system treats the terms as a set of orthogonal vectors. In such a model it is often necessary to adopt a separate, corrective procedure to take into account the correlations between terms. In this paper, we propose a systematic method (the generalized vector space model) to compute term correlations directly from automatic indexing scheme. We also demonstrate how such correlations can be included with minimal modification in the existing vector based information retrieval systems.

Honokiol Prodrug Nanoparticles Based on In Situ Albumin Binding for Long Circulation and High Tumor Uptake

2021 ◽  
Vol 12 (10) ◽  
pp. 1589-1595
Author(s):  
Lixue Chen ◽  
Shengnan Li ◽  
Yanfang Ding ◽  
Changyuan Wang ◽  
Sitong Zhang ◽  
...  
Keyword(s):  
Albumin Binding ◽  
Tumor Uptake ◽  
High Tumor Uptake

scholarly journals Influence of Molecular Design on the Targeting Properties of ABD-Fused Mono- and Bi-Valent Anti-HER3 Affibody Therapeutic Constructs

Cells ◽  
2018 ◽  
Vol 7 (10) ◽  
pp. 164 ◽  
Author(s):  
Mohamed Altai ◽  
Charles Leitao ◽  
Sara Rinne ◽  
Anzhelika Vorobyeva ◽  
Christina Atterby ◽  
...  
Keyword(s):  
Half Life ◽  
Molecular Design ◽  
Growth Factor Receptor ◽  
Fusion Construct ◽  
Affibody Molecules ◽  
Binding Domains ◽  
Biodistribution Studies ◽  
C Terminus ◽  
Type 3

Overexpression of human epidermal growth factor receptor type 3 (HER3) is associated with tumour cell resistance to HER-targeted therapies. Monoclonal antibodies (mAbs) targeting HER3 are currently being investigated for treatment of various types of cancers. Cumulative evidence suggests that affibody molecules may be appropriate alternatives to mAbs. We previously reported a fusion construct (3A3) containing two HER3-targeting affibody molecules flanking an engineered albumin-binding domain (ABD035) included for the extension of half-life in circulation. The 3A3 fusion protein (19.7 kDa) was shown to delay tumour growth in mice bearing HER3-expressing xenografts and was equipotent to the mAb seribantumab. Here, we have designed and explored a series of novel formats of anti-HER3 affibody molecules fused to the ABD in different orientations. All constructs inhibited heregulin-induced phosphorylation in HER3-expressing BxPC-3 and DU-145 cell lines. Biodistribution studies demonstrated extended the half-life of all ABD-fused constructs, although at different levels. The capacity of our ABD-fused proteins to accumulate in HER3-expressing tumours was demonstrated in nude mice bearing BxPC-3 xenografts. Formats where the ABD was located on the C-terminus of affibody binding domains (3A, 33A, and 3A3) provided the best tumour targeting properties in vivo. Further development of these promising candidates for treatment of HER3-overexpressing tumours is therefore justified.

DNA-binding regulates site-specific ubiquitination of IRF-1

2013 ◽  
Vol 449 (3) ◽  
pp. 707-717 ◽  
Author(s):  
Vivien Landré ◽  
Emmanuelle Pion ◽  
Vikram Narayan ◽  
Dimitris P. Xirodimas ◽  
Kathryn L. Ball
Keyword(s):  
Dna Binding ◽  
E3 Ligase ◽  
Binding Domain ◽  
Dna Binding Domain ◽  
Docking Site ◽  
Interacting Protein ◽  
Site Specific ◽  
E3 Ligases ◽  
Intrinsically Disordered ◽  
C Terminus

Understanding the determinants for site-specific ubiquitination by E3 ligase components of the ubiquitin machinery is proving to be a challenge. In the present study we investigate the role of an E3 ligase docking site (Mf2 domain) in an intrinsically disordered domain of IRF-1 [IFN (interferon) regulatory factor-1], a short-lived IFNγ-regulated transcription factor, in ubiquitination of the protein. Ubiquitin modification of full-length IRF-1 by E3 ligases such as CHIP [C-terminus of the Hsc (heat-shock cognate) 70-interacting protein] and MDM2 (murine double minute 2), which dock to the Mf2 domain, was specific for lysine residues found predominantly in loop structures that extend from the DNA-binding domain, whereas no modification was detected in the more conformationally flexible C-terminal half of the protein. The E3 docking site was not available when IRF-1 was in its DNA-bound conformation and cognate DNA-binding sequences strongly suppressed ubiquitination, highlighting a strict relationship between ligase binding and site-specific modification at residues in the DNA-binding domain. Hyperubiquitination of a non-DNA-binding mutant supports a mechanism where an active DNA-bound pool of IRF-1 is protected from polyubiquitination and degradation.

Simple topology: FtsK-directed recombination at the dif site

2013 ◽  
Vol 41 (2) ◽  
pp. 595-600 ◽  
Author(s):  
Ian Grainge
Keyword(s):  
Escherichia Coli ◽  
Cell Division ◽  
Chromosome Segregation ◽  
Motor Domain ◽  
Site Specific ◽  
Multifunctional Protein ◽  
Supercoiled Plasmid ◽  
C Terminus ◽  
Dna Translocase

FtsK is a multifunctional protein, which, in Escherichia coli, co-ordinates the essential functions of cell division, DNA unlinking and chromosome segregation. Its C-terminus is a DNA translocase, the fastest yet characterized, which acts as a septum-localized DNA pump. FtsK's C-terminus also interacts with the XerCD site-specific recombinases which act at the dif site, located in the terminus region. The motor domain of FtsK is an active translocase in vitro, and, when incubated with XerCD and a supercoiled plasmid containing two dif sites, recombination occurs to give unlinked circular products. Despite years of research the mechanism for this novel form of topological filter remains unknown.

scholarly journals A Novel ELISA Assay for the Detection of Anti-Prothrombin Antibodies in Antiphospholipid Syndrome Patients at High Risk of Thrombosis

2021 ◽  
Vol 12 ◽  
Author(s):  
Mathivanan Chinnaraj ◽  
Vittorio Pengo ◽  
Nicola Pozzi
Keyword(s):  
High Risk ◽  
Antiphospholipid Syndrome ◽  
Linear Correlation ◽  
Elisa Assay ◽  
Plastic Plate ◽  
Site Specific ◽  
Terminal Fragment ◽  
C Terminus ◽  
Improve Stability

Autoantibodies targeting prothrombin (aPT) can be found in antiphospholipid syndrome (APS) patients. However, their detection has proven difficult to standardize. Here, we developed a new ELISA assay to improve the identification of aPT and compared its performance with currently available anti-phosphatidylserine/prothrombin antibodies (aPS/PT) and autoantibodies targeting prothrombin bound to the plastic plate (aPT-A) assays using a cohort of 27 APS patients at high risk of thrombosis. We generated a novel prothrombin variant, ProTS525A-Biot, carrying an artificial tag at the C-terminus suitable for site-specific biotinylation and added the mutation S525A to improve stability. ProTS525A-Biot was immobilized to neutravidin-coated plates at the desired density and with a defined orientation, i.e., pointing the N-terminal fragment-1 toward the solvent. Antibodies against ProTS525A-Biot (aPT-Bio) were found in 24 out of 27 triple-positive APS patients (88%). When compared to aPS/PT and aPT-A, aPT-Bio showed an excellent linear correlation with aPS/PT (R2 = 0.85) but not with aPT-A (R2 = 0.40). Since aPS/PT but not aPT-A are an emerging biomarker of thrombosis in APS, this method may find utility for detecting pathogenic aPT in APS but also other prothrombotic conditions such as COVID-19.

Albumin-Binding and Angiogenic Domains of SPARC Located at Its C-Terminus.

2009 ◽  
Author(s):  
D. Knauer ◽  
L. Hwang ◽  
C. Lowe ◽  
J. Hwang ◽  
M. Norng ◽  
...  
Keyword(s):  
Albumin Binding ◽  
C Terminus

Site-specific modification of proteins by ExoT-mediated ADP-ribosylation

TECHNOLOGY ◽  
2015 ◽  
Vol 03 (01) ◽  
pp. 72-78
Author(s):  
Chia-Lun Jack Tsai ◽  
Slim Sassi ◽  
Brian Seed
Keyword(s):  
Chemical Diversity ◽  
Chain Reaction ◽  
Site Specific ◽  
Bar Codes ◽  
C Terminus ◽  
Highly Sensitive ◽  
Wide Range ◽  
Polymerase Chain ◽  
Highly Sensitive Detection ◽  
Adp Ribosyltransferase

Proteins bearing short sequence tags (ExoTags) can be specifically modified in a reaction catalyzed by the ADP-ribosyltransferase of Pseudomonas ExoT. ExoT tolerates a wide range of substituents at the adenosine N6 position, allowing the convenient installation of chemical diversity at the site of the tag. The ExoTag can be placed at either the N - or the C -terminus of the protein of interest or internally. The minimum tag is Arg-Leu-Ser-Arg (RLSR). Tandem copies of the minimal ExoTag enhance the efficiency of modification and allow modification at multiple sites within the tag. ExoT can be used to conjugate NAD-RNA to ExoTag bearing proteins, providing a convenient method for introducing nucleic acid bar codes for highly sensitive detection of proteins by polymerase chain reaction.

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