18 results on '"Calise Bahou"'
Search Results
2. Photoimmunotherapy Using Cationic and Anionic Photosensitizer-Antibody Conjugates against HIV Env-Expressing Cells
- Author
-
Mohammad Sadraeian, Calise Bahou, Edgar Ferreira da Cruz, Luíz Mário Ramos Janini, Ricardo Sobhie Diaz, Ross W. Boyle, Vijay Chudasama, and Francisco Eduardo Gontijo Guimarães
- Subjects
HIV immunotherapy ,photoimmunotherapy ,photodynamic therapy ,porphyrin ,phthalocyanine ,HIV-infected cell ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Different therapeutic strategies have been investigated to target and eliminate HIV-1-infected cells by using armed antibodies specific to viral proteins, with varying degrees of success. Herein, we propose a new strategy by combining photodynamic therapy (PDT) with HIV Env-targeted immunotherapy, and refer to it as HIV photoimmunotherapy (PIT). A human anti-gp41 antibody (7B2) was conjugated to two photosensitizers (PSs) with different charges through different linking strategies; “Click” conjugation by using an azide-bearing porphyrin attached via a disulfide bridge linker with a drug-to-antibody ratio (DAR) of exactly 4, and “Lysine” conjugation by using phthalocyanine IRDye 700DX dye with average DARs of 2.1, 3.0 and 4.4. These photo-immunoconjugates (PICs) were compared via biochemical and immunological characterizations regarding the dosimetry, solubility, and cell targeting. Photo-induced cytotoxicity of the PICs were compared using assays for apoptosis, reactive oxygen species (ROS), photo-cytotoxicity, and confocal microscopy. Targeted phototoxicity seems to be primarily dependent on the binding of PS-antibody to the HIV antigen on the cell membrane, whilst being independent of the PS type. This is the first report of the application of PIT for HIV immunotherapy by killing HIV Env-expressing cells.
- Published
- 2020
- Full Text
- View/download PDF
3. Hydrogel crosslinking via thiol-reactive pyridazinediones
- Author
-
Calise Bahou, Richard Spears, Angela Ramirez Rosales, Lea Rochet, Lydia Barber, Vijay Chudasama, and Christopher Spicer
- Abstract
Thiol-reactive Michael acceptors are commonly used for the formation of chemically crosslinked hydrogels. In this paper, we address the drawbacks of many Michael acceptors by introducing pyridazinediones as new crosslinking agents. Through the use of pyridiazinediones and their mono- or di-brominated analogues, we show that the mechanical strength, swelling ratio, and rate of gelation can all be controlled in a pH sensitive manner. Moreover, we demonstrate that the degradation of pyridazinedione-gels can be induced by the addition of thiols, thus providing a route to responsive or dynamic gels. We anticipate that our results will provide a valuable and complementary addition to the existing toolkit of crosslinking agents, allowing researchers to tune and rationally design the properties of biomedical hydrogels.
- Published
- 2023
4. A novel thiol-labile cysteine protecting group for peptide synthesis based on a pyridazinedione (PD) scaffold
- Author
-
Léa N. C. Rochet, Fabien Thoreau, Clíona McMahon, Calise Bahou, R.J. Spears, Nafsika Forte, Ioanna A. Thanasi, Monika Shamsabadi, Vijay Chudasama, and James R. Baker
- Subjects
chemistry.chemical_classification ,Scaffold ,010405 organic chemistry ,Metals and Alloys ,Model system ,General Chemistry ,010402 general chemistry ,Native chemical ligation ,01 natural sciences ,Combinatorial chemistry ,Catalysis ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,chemistry.chemical_compound ,chemistry ,Materials Chemistry ,Ceramics and Composites ,Peptide synthesis ,Thiol ,Protecting group ,Solid-Phase Synthesis Techniques ,Cysteine - Abstract
Herein we report a thiol-labile cysteine protecting group based on an unsaturated pyridazinedione (PD) scaffold. We establish compatibility of the PD in conventional solid phase peptide synthesis (SPPS), showcasing this in the on-resin synthesis of biologically relevant oxytocin. Furthermore, we establish the applicability of the PD protecting group towards both microwave-assisted SPPS and native chemical ligation (NCL) in a model system.
- Published
- 2022
5. Chemical generation of checkpoint inhibitory T cell engagers (CiTEs) for the treatment of cancer
- Author
-
Peter A. Szijj, Melissa A. Gray, Mikaela K. Ribi, Calise Bahou, João C. F. Nogueira, Carolyn R. Bertozzi, and Vijay Chudasama
- Abstract
Bispecific antibodies (bsAbs) provide enticing therapeutic opportunities in the area of immunotherapy, especially in the field of immuno-oncology. These constructs can bind two separate antigenic epitopes and thus provide access to unique mechanisms of action (MoAs). A key MoA is unlocked by bispecific T cell engagers (BiTEs), which cause T cells to be cross-linked with a targeted cancer cell, ultimately leading to death of the targeted cell. It has been shown that the combination of a BiTE with checkpoint inhibition, such as blockade of the PD-1/PD-L1 pathway, can lead to a synergistic effect and greater efficacy. Constructs built from a BiTE core (anti-CD3/anti-cancer antigen) with an immunomodulatory protein added, have been dubbed checkpoint-inhibitory T cell-engagers (CiTEs). Both bsAbs and CiTEs have traditionally been generated via protein engineering. However, recently, improved chemical methods for the construction of bsAbs have been reported. This includes a strategy developed by the Chudasama and Baker groups to synthesize homogenous fragment-based bsAbs from antibodies’ fragments antigen binding (Fabs), utilising click-enabled pyridazinediones (PDs) for functional disulfide re-bridging, followed by strain-promoted inverse electron-demand Diels-Alder cycloaddition (SPIEDAC) click chemistry to attach the two Fabs to each other. In this paper, we describe a first-in-class chemical method to generate biotin-functionalized three-protein conjugates, building significantly on the previously described PD-method. The three-protein constructs generated here include two such CiTE molecules, one containing an anti-PD-1 Fab, the other containing an immunomodulatory enzyme Salmonella typhimurium sialidase; FabCD3-FabHER2-FabPD-1-Biotin and FabHER2-FabCD3-Sia-Biotin. These constructs (along with suitable controls) were tested for their biological activity, and each of their protein components were shown to retain their function. Their efficacy was also compared to a simpler BiTE scaffold and was shown to be superior, with the sialidase-containing CiTE especially showing significantly enhanced potency in vitro. The chemical method described here has the potential to enable the rapid generation of a plethora of multi-protein constructs, which we envisage would be especially useful in hit-identification screening but could also potentially be scaled up for drug-development after further optimization.
- Published
- 2022
6. Photoinduced Photosensitizer–Antibody Conjugates Kill HIV Env-Expressing Cells, Also Inactivating HIV
- Author
-
Ricardo Sobhie Diaz, Francisco Eduardo Gontijo Guimarães, Vijay Chudasama, Edgar Ferreira da Cruz, Calise Bahou, Mohammad Sadraeian, Luiz Mario Janini, and Ross W. Boyle
- Subjects
biology ,Chemistry ,viruses ,General Chemical Engineering ,medicine.medical_treatment ,Human immunodeficiency virus (HIV) ,virus diseases ,Photoimmunotherapy ,General Chemistry ,Immunotherapy ,medicine.disease_cause ,Virology ,Article ,TERAPIA FOTODINÂMICA ,Virus ,0904 Chemical Engineering, 0912 Materials Engineering ,medicine ,biology.protein ,Photosensitizer ,In patient ,Antibody ,QD1-999 ,Conjugate - Abstract
HIV-infected cells persist for decades in patients administered with antiretroviral therapy (ART). Meanwhile, an alarming surge in drug-resistant HIV viruses has been occurring. Addressing these issues, we propose the application of photoimmunotherapy (PIT) against not only HIV Env-expressing cells but also HIV. Previously, we showed that a human anti-gp41 antibody (7B2) conjugated to cationic or anionic photosensitizers (PSs) could specifically target and kill the HIV Env-expressing cells. Here, our photolysis studies revealed that the binding of photoimmunoconjugates (PICs) on the membrane of HIV Env-expressing cells is sufficient to induce necrotic cell death due to physical damage to the membrane by singlet oxygen, which is independent of the type of PSs. This finding persuaded us to study the virus photoinactivation of PICs using two HIV-1 strains, X4 HIV-1 NL4-3 and JR-CSF virus. We observed that the PICs could destroy the viral strains, probably via physical damage on the HIV envelope. In conclusion, we report the application of PIT as a possible dual-tool for HIV immunotherapy and ART by killing HIV-expressing cells and cell-free HIV, respectively.
- Published
- 2021
7. Leucine-rich alpha-2-glycoprotein 1 (LRG1) as a novel ADC target
- Author
-
Carlotta Camilli, Vijay Chudasama, Faiza Javaid, Calise Bahou, Stephen E. Moss, John Greenwood, Jack W.D. Blackburn, Camilla Pilotti, David Kallenberg, and James R. Baker
- Subjects
medicine.drug_class ,Monoclonal antibody ,Biochemistry, Genetics and Molecular Biology (miscellaneous) ,Biochemistry ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,In vivo ,medicine ,Molecular Biology ,030304 developmental biology ,0303 health sciences ,Dipeptide ,biology ,In vitro ,3. Good health ,Chemistry ,Monomethyl auristatin E ,chemistry ,Chemistry (miscellaneous) ,030220 oncology & carcinogenesis ,Cancer research ,biology.protein ,Antibody ,Linker ,Conjugate - Abstract
Leucine-rich alpha-2-glycoprotein 1 (LRG1) is present abundantly in the microenvironment of many tumours where it contributes to vascular dysfunction, which impedes the delivery of therapeutics. In this work we demonstrate that LRG1 is predominantly a non-internalising protein. We report the development of a novel antibody–drug conjugate (ADC) comprising the anti-LRG1 hinge-stabilised IgG4 monoclonal antibody Magacizumab coupled to the anti-mitotic payload monomethyl auristatin E (MMAE) via a cleavable dipeptide linker using the site-selective disulfide rebridging dibromopyridazinedione (diBrPD) scaffold. It is demonstrated that this ADC retains binding post-modification, is stable in serum and effective in in vitro cell studies. We show that the extracellular LRG1-targeting ADC provides an increase in survival in vivo when compared against antibody alone and similar anti-tumour activity when compared against standard chemotherapy, but without undesired side-effects. LRG1 targeting through this ADC presents a novel and effective proof-of-concept en route to improving the efficacy of cancer therapeutics., LRG1 is present abundantly in the microenvironment of many tumours. LRG1 targeting through the reported non-internalising ADC presents a novel and effective proof-of-concept en route to improving the efficacy of cancer therapeutics.
- Published
- 2021
8. The use of bromopyridazinedione derivatives in chemical biology
- Author
-
Calise Bahou and Vijay Chudasama
- Subjects
Organic Chemistry ,Proteins ,Cysteine ,Disulfides ,Physical and Theoretical Chemistry ,Peptides ,Biochemistry ,Biology - Abstract
Tools that facilitate the chemical modification of peptides and proteins are gaining an increasing amount of interest across many avenues of chemical biology as they enable a plethora of therapeutic, imaging and diagnostic applications. Cysteine residues and disulfide bonds have been highlighted as appealing targets for modification due to the highly homogenous nature of the products that can be formed through their site-selective modification. Amongst the reagents available for the site-selective modification of cysteine(s)/disulfide(s), pyridazinediones (PDs) have played a particularly important and enabling role. In this review, we outline the unique chemical features that make PDs especially well-suited to cysteine/disulfide modification on a wide variety of proteins and peptides, as well as provide context as to the problems solved (and applications enabled) by this technology.
- Published
- 2022
9. A Plug-and-Play Approach for the De Novo Generation of Dually Functionalized Bispecifics
- Author
-
Peter A. Szijj, Vijay Chudasama, James R. Baker, Stephen Caddick, Antoine Maruani, João C. F. Nogueira, and Calise Bahou
- Subjects
Pharmacology ,Bispecific antibody ,010405 organic chemistry ,Plug and play ,Chemistry ,Organic Chemistry ,Biomedical Engineering ,Pharmaceutical Science ,Bioengineering ,02 engineering and technology ,Computational biology ,Limiting ,021001 nanoscience & nanotechnology ,01 natural sciences ,Antibody fragments ,Epitope ,0104 chemical sciences ,3. Good health ,Click chemistry ,0210 nano-technology ,Biotechnology - Abstract
Diseases are multifactorial, with redundancies and synergies between various pathways. However, most of the antibody-based therapeutics on the market interact with only one target, thus limiting their efficacy. The targeting of multiple epitopes could improve the therapeutic index of treatment and counteract mechanisms of resistance. To this effect, a new class of therapeutics has emerged: bispecific antibodies. Bispecific formation using chemical methods is rare and low-yielding and/or requires a large excess of one of the two proteins to avoid homodimerization and heterogeneity. In order for chemically prepared bispecifics to deliver their full potential, high-yielding, modular, and reliable cross-linking technologies are required. Herein, we describe a novel approach not only for the rapid and high-yielding chemical generation of bispecific antibodies from native antibody fragments, but also for the site-specific dual functionalization of the resulting bioconjugates. Based on orthogonal clickable functional groups, this strategy enables the assembly of functionalized bispecifics with controlled loading in a modular and convergent manner.
- Published
- 2020
10. Minireview: Addressing the retro-Michael instability of maleimide bioconjugates
- Author
-
Peter A. Szijj, Vijay Chudasama, and Calise Bahou
- Subjects
Immunoconjugates ,Bioconjugation ,010405 organic chemistry ,Chemistry ,Mechanism (biology) ,Rational design ,Cancer therapy ,Chemical biology ,010402 general chemistry ,01 natural sciences ,Combinatorial chemistry ,Small molecule ,3. Good health ,0104 chemical sciences ,Maleimides ,Structure-Activity Relationship ,chemistry.chemical_compound ,Drug Discovery ,Humans ,Molecular Medicine ,Structure–activity relationship ,Maleimide - Abstract
Bioconjugation, the modification of biological macromolecules such as proteins, is an up and coming area in the field of chemical biology. Antibody-drug conjugates (ADCs), combining the antigen-selectivity of natural antibodies with the cytotoxic potency of small molecule drugs, are a powerful therapeutic technology. Four such constructs are currently on the market for cancer therapy. However, the conjugation methodology employed in these therapeutics is far from ideal. Herein we provide an overview on methods that attempt to increase the safety and efficacy of ADCs via "self-hydrolysing maleimides" or by improving the stability of maleimide-conjugates by other means. We find that some very promising reagents have been reported, however the mechanism by which each of these reagents acts is not clear, thus limiting rational design for some strategies.
- Published
- 2018
11. A Plug-and-Play Platform for the Formation of Trifunctional Cysteine Bioconjugates that also Offers Control over Thiol Cleavability
- Author
-
Elizabeth A. Love, Vijay Chudasama, Richard J Spears, James R. Baker, Peter A. Szijj, Archie Wall, Calise Bahou, Faiza Javaid, and Afrah Sattikar
- Subjects
Biomedical Engineering ,Chemical biology ,Pharmaceutical Science ,Bioengineering ,Peptide ,02 engineering and technology ,01 natural sciences ,Residue (chemistry) ,chemistry.chemical_compound ,Cysteine ,Sulfhydryl Compounds ,Pharmacology ,chemistry.chemical_classification ,010405 organic chemistry ,Chemistry ,Hydrolysis ,Communication ,Organic Chemistry ,Leaving group ,Glutathione ,021001 nanoscience & nanotechnology ,Combinatorial chemistry ,0104 chemical sciences ,Thiol ,0210 nano-technology ,Linker ,Biotechnology - Abstract
Linkers that enable the site-selective synthesis of chemically modified proteins are of great interest to the field of chemical biology. Homogenous bioconjugates often show advantageous pharmacokinetic profiles and consequently increased efficacy in vivo. Cysteine residues have been exploited as a route to site-selectively modify proteins, and many successfully approved therapeutics make use of cysteine directed conjugation reagents. However, commonly used linkers, including maleimide-thiol conjugates, are not stable to the low concentrations of thiol present in blood. Furthermore, only a few cysteine-targeting reagents enable the site-selective attachment of multiple functionalities: a useful tool in the fields of theranostics and therapeutic blood half-life extension. Herein, we demonstrate the application of the pyridazinedione motif to enable site-selective attachment of three functionalities to a protein bearing a single cysteine residue. Extending upon previously documented dual modification work, here we demonstrate that by exploiting a bromide leaving group as an additional reactive point on the pyridazinedione scaffold, a thiol or aniline derivative can be added to a protein, post-conjugation. Thiol cleavability appraisal of the resultant C-S and C-N linked thio-bioconjugates demonstrated C-S functionalized linkers to be cleavable and C-N functionalized linkers to be noncleavable when incubated in an excess of glutathione. The plug-and-play trifunctional platform was exemplified by attaching clinically relevant motifs: biotin, fluorescein, a polyethylene glycol chain, and a model peptide. This platform provides a rare opportunity to combine up to three functionalities on a protein in a site-selective fashion. Furthermore, by selecting the use of a thiol or an amine for functionalization, we provide unique control over linker cleavability toward thiols, allowing this novel linker to be applied in a range of physiological environments.
- Published
- 2021
12. One-Pot Thiol-Amine Bioconjugation to Maleimides; Simultaneous Stabilisation and Dual Functionalisation
- Author
-
Archie Wall, Karl Nicholls, Alfie G Wills, Nafsika Forte, Michelle T. Ma, Vijay Chudasama, Calise Bahou, James R. Baker, and Lisa Bonin
- Subjects
chemistry.chemical_classification ,Bioconjugation ,010405 organic chemistry ,General Chemistry ,010402 general chemistry ,01 natural sciences ,Combinatorial chemistry ,0104 chemical sciences ,Chemistry ,Hydrolysis ,chemistry.chemical_compound ,chemistry ,Electrophile ,Thiol ,Amine gas treating ,Reactivity (chemistry) ,Maleimide ,Conjugate - Abstract
Maleimide chemistry is widely used in the site-selective modification of proteins. However, hydrolysis of the resultant thiosuccinimides is required to provide robust stability to the bioconjugates. Herein, we present an alternative approach that affords simultaneous stabilisation and dual functionalisation in a one pot fashion. By consecutive conjugation of a thiol and an amine to dibromomaleimides, we show that aminothiomaleimides can be generated extremely efficiently. Furthermore, the amine serves to deactivate the electrophilicity of the maleimide, precluding further reactivity and hence generating stable conjugates. We have applied this conjugation strategy to peptides and proteins to generate stabilised trifunctional conjugates. We propose that this stabilisation-dual modification strategy could have widespread use in the generation of diverse conjugates., An alternative approach to maleimide conjugate stabilisation is presented, by the consecutive addition of a thiol and an amine to dibromomaleimides. The amine serves to simultaneously deactivate the maleimide and enable dual functionalisation.
- Published
- 2020
13. A Plug-and-Play Approach for the
- Author
-
Antoine, Maruani, Peter A, Szijj, Calise, Bahou, João C F, Nogueira, Stephen, Caddick, James R, Baker, and Vijay, Chudasama
- Subjects
Epitopes ,Antibodies, Bispecific ,Antibodies, Monoclonal ,Click Chemistry - Abstract
Diseases are multifactorial, with redundancies and synergies between various pathways. However, most of the antibody-based therapeutics on the market interact with only one target, thus limiting their efficacy. The targeting of multiple epitopes could improve the therapeutic index of treatment and counteract mechanisms of resistance. To this effect, a new class of therapeutics has emerged: bispecific antibodies. Bispecific formation using chemical methods is rare and low-yielding and/or requires a large excess of one of the two proteins to avoid homodimerization and heterogeneity. In order for chemically prepared bispecifics to deliver their full potential, high-yielding, modular, and reliable cross-linking technologies are required. Herein, we describe a novel approach not only for the rapid and high-yielding chemical generation of bispecific antibodies from native antibody fragments, but also for the site-specific dual functionalization of the resulting bioconjugates. Based on orthogonal clickable functional groups, this strategy enables the assembly of functionalized bispecifics with controlled loading in a modular and convergent manner.
- Published
- 2020
14. Photoimmunotherapy using cationic and anionic photosensitizer-antibody conjugates against HIV Env-expressing cells
- Author
-
Francisco Eduardo Gontijo Guimarães, Edgar Ferreira da Cruz, Ricardo Sobhie Diaz, Luiz Mario Janini, Vijay Chudasama, Calise Bahou, Mohammad Sadraeian, and Ross W. Boyle
- Subjects
0301 basic medicine ,Immunoconjugates ,photoimmunotherapy ,medicine.medical_treatment ,Fluorescent Antibody Technique ,Photodynamic therapy ,Apoptosis ,HIV Infections ,Virus Replication ,01 natural sciences ,lcsh:Chemistry ,Photosensitizer ,Cytotoxicity ,lcsh:QH301-705.5 ,Spectroscopy ,Cells, Cultured ,Photosensitizing Agents ,biology ,Chemistry ,env Gene Products, Human Immunodeficiency Virus ,virus diseases ,Antibodies, Monoclonal ,General Medicine ,Flow Cytometry ,Computer Science Applications ,phthalocyanine ,photodynamic therapy ,Antibody ,porphyrin ,Anions ,HIV immunotherapy ,medicine.drug_class ,Anti-HIV Agents ,Monoclonal antibody ,Catalysis ,Article ,Inorganic Chemistry ,03 medical and health sciences ,0399 Other Chemical Sciences, 0604 Genetics, 0699 Other Biological Sciences ,Antigen ,Cations ,Cell Line, Tumor ,medicine ,biochemistry ,Humans ,Physical and Theoretical Chemistry ,HIV-infected cell ,Molecular Biology ,Chemical Physics ,010405 organic chemistry ,Organic Chemistry ,HIV ,Photoimmunotherapy ,Immunotherapy ,Molecular biology ,0104 chemical sciences ,030104 developmental biology ,Photochemotherapy ,lcsh:Biology (General) ,lcsh:QD1-999 ,monoclonal antibody ,biology.protein ,Reactive Oxygen Species - Abstract
Different therapeutic strategies have been investigated to target and eliminate HIV-1-infected cells by using armed antibodies specific to viral proteins, with varying degrees of success. Herein, we propose a new strategy by combining photodynamic therapy (PDT) with HIV Env-targeted immunotherapy, and refer to it as HIV photoimmunotherapy (PIT). A human anti-gp41 antibody (7B2) was conjugated to two photosensitizers (PSs) with different charges through different linking strategies, &ldquo, Click&rdquo, conjugation by using an azide-bearing porphyrin attached via a disulfide bridge linker with a drug-to-antibody ratio (DAR) of exactly 4, and &ldquo, Lysine&rdquo, conjugation by using phthalocyanine IRDye 700DX dye with average DARs of 2.1, 3.0 and 4.4. These photo-immunoconjugates (PICs) were compared via biochemical and immunological characterizations regarding the dosimetry, solubility, and cell targeting. Photo-induced cytotoxicity of the PICs were compared using assays for apoptosis, reactive oxygen species (ROS), photo-cytotoxicity, and confocal microscopy. Targeted phototoxicity seems to be primarily dependent on the binding of PS-antibody to the HIV antigen on the cell membrane, whilst being independent of the PS type. This is the first report of the application of PIT for HIV immunotherapy by killing HIV Env-expressing cells.
- Published
- 2020
15. Correction: Use of pyridazinediones as extracellular cleavable linkers through reversible cysteine conjugation
- Author
-
Calise Bahou, Richard J. Spears, Abil E. Aliev, Antoine Maruani, Marcos Fernandez, Faiza Javaid, Peter A. Szijj, James R. Baker, and Vijay Chudasama
- Subjects
Materials Chemistry ,Metals and Alloys ,Ceramics and Composites ,General Chemistry ,Catalysis ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials - Abstract
Correction for ‘Use of pyridazinediones as extracellular cleavable linkers through reversible cysteine conjugation’ by Calise Bahou et al., Chem. Commun., 2019, 55, 14829–14832, https://doi.org/10.1039/C9CC08362F.
- Published
- 2022
16. Use of pyridazinediones as extracellular cleavable linkers through reversible cysteine conjugation
- Author
-
James R. Baker, Marcos Fernández, Vijay Chudasama, Richard J Spears, Peter A. Szijj, Calise Bahou, Antoine Maruani, Abil E. Aliev, and Faiza Javaid
- Subjects
Linked protein ,010405 organic chemistry ,Metals and Alloys ,General Chemistry ,Glutathione ,010402 general chemistry ,Human serum albumin ,01 natural sciences ,Catalysis ,3. Good health ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,chemistry.chemical_compound ,chemistry ,Biochemistry ,Materials Chemistry ,Ceramics and Composites ,medicine ,Extracellular ,Cleavable linker ,Maleimide ,Linker ,medicine.drug ,Cysteine - Abstract
Herein we report a retro-Michael deconjugation pathway of thiol-pyridazinedione linked protein bioconjugates to provide a novel cleavable linker technology. We demonstrate that the novel pyridazinedione linker does not suffer from off-target modification with blood thiols (e.g., glutathione, human serum albumin (HSA)), which is in sharp contrast to an analogous maleimide linker.
- Published
- 2019
17. A Plug-and-Play Approach for the De Novo Generation of Dually Functionalised Bispecifics
- Author
-
Antoine Maruani, Peter A. Szijj, Calise Bahou, João C. F. Nogueira, Stephen Caddick, James R. Baker, and Vijay Chudasama
- Abstract
Diseases are multifactorial, with redundancies and synergies between various pathways. However, most of the antibody-based therapeutics in clinical trials and on the market interact with only one target thus limiting their efficacy. The targeting of multiple epitopes could improve the therapeutic index of treatment and counteract mechanisms of resistance. To this effect, a new class of therapeutics emerged: bispecific antibodies.Bispecific formation using chemical methods is rare and low yielding and/or requires a large excess of one of the two proteins to avoid homodimerisation. In order for chemically prepared bispecifics to deliver their full potential, high-yielding, modular and reliable cross-linking technologies are required. Herein, we describe a novel approach not only for the rapid and high-yielding chemical generation of bispecific antibodies from native antibody fragments, but also for the site-specific dual functionalisation of the resulting bioconjugates. Based on orthogonal clickable functional groups, this strategy enables the assembly of functionalised bispecifics with controlled loading in a modular and convergent manner.
- Published
- 2019
18. Disulfide Modified IgG1: An Investigation of Biophysical Profile and Clinically Relevant Fc Interactions
- Author
-
Vijay Chudasama, Richard J Spears, Elizabeth A. Love, James R. Baker, Siobhán Leonard, Calise Bahou, Kathryn Armour, and Antoine Maruani
- Subjects
Immunoconjugates ,Biomedical Engineering ,Pharmaceutical Science ,Bioengineering ,02 engineering and technology ,01 natural sciences ,Immunoglobulin G ,Biophysical Phenomena ,Humans ,Disulfides ,Pharmacology ,Antibody-dependent cell-mediated cytotoxicity ,Bioconjugation ,biology ,010405 organic chemistry ,Chemistry ,Organic Chemistry ,Receptors, IgG ,Rational design ,Antibody-Dependent Cell Cytotoxicity ,Trastuzumab ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Immunoglobulin Fc Fragments ,Covalent bond ,biology.protein ,Biophysics ,Antibody ,0210 nano-technology ,Function (biology) ,Biotechnology ,Conjugate - Abstract
Modification of immunoglobulin G (IgG) 1 proteins in cancer treatment is a rapidly growing field of research. Antibody-drug conjugates (ADCs) exploit the targeted nature of this immunotherapy by conjugating highly potent drugs to antibodies, allowing for effective transport of cargo(s) to cancerous cells. Of the many bioconjugation strategies now available for the formation of highly homogeneous ADCs, disulfide modification is considered an effective, low-cost, and widely accepted method for modifying IgG1s for improved clinical benefit. However, little is known about how disulfide modification impacts clinically relevant fragment crystallizable (Fc) region interactions. Although often overlooked as a secondary ADC function, Fc interactions could prove key in the rational design of cancer cell-targeting ADCs through consideration of potent mechanisms such as antibody-dependent cellular cytotoxicity (ADCC). This work explores different IgG1 disulfide modification techniques and the effect they have on quantifiable secondary IgG1 Fc interactions (e.g., CD16a and FcRn). The solvent accessible disulfide residues of trastuzumab, a clinically relevant IgG1, were modified to provide a range of bioconjugates with differing amounts of interchain covalent linkages. It was found that by natively rebridging the IgG1 model, all tested Fc functionalities were not significantly affected. Additionally, in non Fc-specific biophysical experiments (e.g., thermal stability/aggregation), the natively rebridged species provided an exceptional profile, showing no significant change from the tested native antibody. Conjugates with significant disruption of the covalent connectivity of IgG1 chains resulted in a suboptimal Fc profile (CD16a kinetics or ADCC activity), in addition to substandard non Fc-specific attributes (thermal stability). These results advocate native disulfide rebridging as an excellent synthetic strategy for forming homogeneous IgG1 bioconjugates, with no reported negative impact on biophysical profile relative to the native antibody.
- Published
- 2019
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.