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Orders Norzivirales and Timlovirales
Published in Paul Pumpens, Peter Pushko, Philippe Le Mercier, Virus-Like Particles, 2022
Paul Pumpens, Peter Pushko, Philippe Le Mercier
At last, the AP205 VLPs greatly contributed to the elaboration of the highly efficient SpyTag/SpyCatcher plug-and-display methodology (Brune et al. 2016; Thrane et al. 2016). This methodology was based on the so-called bacterial superglue phenomenon, when the isopeptide bond was spontaneously formed between a peptide and its protein couple, derived from specific domains of certain bacterial proteins (Veggiani et al. 2014; Tan et al. 2016; Bonnet et al. 2017). The two binding couples were used: SpyTag peptide/SpyCatcher protein, derived by splitting the CnaB2 domain of the fibronectin-binding protein FbaB from Streptococcus pyogenes (Zakeri et al. 2012) and SnoopTag peptide/SnoopCatcher protein, derived by splitting the D4 domain of RrgA adhesin from Streptococcus pneumoniae (Veggiani et al. 2016).
Fundamentals of Modern Peptide Synthesis
Published in Mesut Karahan, Synthetic Peptide Vaccine Models, 2021
Protein synthesis is important to study the structure of natural proteins, to investigate how protein structure and function are formed by the amino acid sequence and to understand the synthesis mechanism. However, it is not possible to form this structure by simply mixing the amino acids together. Protective groups are often necessary to avoid undesirable reactions. Chemical peptide synthesis generally starts from the carboxyl groups (C-terminus) of the peptide and proceeds towards the amino groups (N-terminus). This is the opposite direction of protein biosynthesis. The resulting bond is the amide (peptide) bond. It is necessary to use protective groups to control the C-N coupling reaction. Certain peptide bonds can be formed by protecting the amine group (N-terminus) of one amino acid and the carboxyl group (C-terminus) of the another. The protection of side chain functional groups is necessary to prevent undesirable reactions and to form univocally the goal peptide bond. The peptide bonds are also called eupeptide bonds to distinguish them from isopeptide bonds formed by participating side chain functional groups as is the case of glutathione for example. Peptide synthesis is a multistage process comprising a number of chemical processes. To provide an overall high yield of the goal peptide it is drastically important to have yields close to quantitative at all stages of this complex process. It is also extremely important to avoid even a low racemization at all stages otherwise the obtained peptide will lack the desirable physiological activity (Isidro-Llobet, Álvarez, and Albericio 2009).
Biochemical Parameters: Childhood Diarrhea and Malabsorption Syndrome
Published in Anil Gupta, Biochemical Parameters and the Nutritional Status of Children, 2020
Tissue transglutaminase is a calcium cofactor dependent enzyme that catalyzes the post-translational modification of polypeptides. It results in the formation of an isopeptide bond between the γ-carboxamide group of glutaminyl residue and ε amino group of lysyl residue, which are present either in similar or different polypeptides (Folk and Finlayson 1977). Tissue transglutaminase enzyme is widely distributed in the body tissues. The tissue transglutaminase enzyme is concerned with the cross linking of peptides in the glutamine residue.
Transglutaminase 2 as a therapeutic target for neurological conditions
Published in Expert Opinion on Therapeutic Targets, 2021
Jeffrey W. Keillor, Gail V.W. Johnson
Neurodegenerative diseases are often characterized by the presence of insoluble aggregates of specific disease relevant proteins. In different in vitro experimental paradigms, TG2 can catalyze the formation of isopeptide bonds, rendering proteins less soluble [55,56]. The ability of TG2 to crosslink disease relevant proteins in vitro, is what initially led investigators to examine the role of TG2 in disease pathogenesis, and is still the primary motivation for the continued studies on the role of TG2 in neurodegenerative processes. However, there is a growing awareness that TG2 may be mediating pathological processes independent of its ability to catalyze the formation of isopeptide bonds [34,57–60]. Therefore, continued investigation into how TG2 may contribute to the progression of neurodegenerative diseases is critical.
Virus-like antigen display for cancer vaccine development, what is the potential?
Published in Expert Review of Vaccines, 2018
Adam F. Sander, Pier-Luigi Lollini
We have developed a simple modular system enabling full-length proteins to be directionally displayed at high density on the surface of non-enveloped icosahedral VLPs [14] i.e. facilitating true virus-like epitope display. The system makes use of two highly reactive split-protein tag/catcher binding partners, which interact to form a spontaneous isopeptide bond in a solution [15]. The structural protein of a bacteriophage has been engineered to allow VLPs to present a tag (13 amino acid peptide) or a catcher (116 amino acid protein) on each of the 180 capsid proteins in the VLP. Once these modified VLPs are formed, they can be mixed with a vaccine antigen genetically fused with a tag or catcher. This results in the formation of a stable VLP with high-density, repetitive, and fixed presentation of the vaccine antigen. In the context of anticancer vaccines, the modular vaccine design exploits the VLP backbone to provide both ‘virus-like’ epitope display as well as T-help, which may act in synergy to overcome B cell immune tolerance.
Virus-like particle display of HER2 induces potent anti-cancer responses
Published in OncoImmunology, 2018
Arianna Palladini, Susan Thrane, Christoph M. Janitzek, Jessica Pihl, Stine B. Clemmensen, Willem Adriaan de Jongh, Thomas M. Clausen, Giordano Nicoletti, Lorena Landuzzi, Manuel L. Penichet, Tania Balboni, Marianna L. Ianzano, Veronica Giusti, Thor G. Theander, Morten A. Nielsen, Ali Salanti, Pier-Luigi Lollini, Patrizia Nanni, Adam F. Sander
We have recently developed a highly versatile antigen display platform that unlike existing technologies, effectively facilitates directional covalent attachment of large vaccine antigens at high density on the surface of VLPs.31 The system employs a tag/catcher conjugation system32 that was developed by splitting the CnaB2 domain from the fibronectin-binding protein FbaB of Streptococcus pyogenes into a highly reactive peptide (SpyTag) and protein (SpyCatcher) binding partner. Interaction between SpyTag and SpyCatcher results in spontaneous formation of an isopeptide bond, which occurs at high efficiency in a wide variety of protein contexts and buffer conditions. Here, we produced the full HER2 extracellular domain (subdomains I-IV), genetically fused with SpyCatcher, and attached the fusion antigen (SpyCatcher-HER2) to the surface of AP205 phage derived VLPs, each presenting 360 SpyTag peptides (Fig. 1 A & B). We demonstrate that the vaccine effectively overcomes B-cell tolerance and induce high-titer therapeutically potent anti-HER2 IgG, which i) prevent tumor growth in wild-type FVB mice grafted with mammary carcinoma cells expressing human HER2 and ii) prevent spontaneous development of human HER2-positive mammary carcinomas in tolerant transgenic mice. Thus, the HER2-VLP vaccine has potential to become a tool for treatment and prevention of HER2-positive cancers. The results also provide strong proof-of-concept for the use of the VLP platform to develop self-antigen based vaccines against non-communicable diseases.