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Biorecognition Elements in Biosensors
Published in Sibel A. Ozkan, Bengi Uslu, Mustafa Kemal Sezgintürk, Biosensors, 2023
Michael López Mujica, Alejandro Tamborelli, Virginia Vaschetti, Pablo Gallay, Fabrizio Perrachione, Daiana Reartes, Rocío Delpino, Marcela Rodríguez, María D. Rubianes, Pablo Dalmasso, Gustavo Rivas
Some special antibodies called single-domain antibodies, also known as nanobodies, are derived from heavy-chain antibodies (HCAbs), which are naturally present in all camelidae. These animals produce HCAbs in their serum, lacking Fc fragments and a canonical constant heavy chain 1 (CH1) domain in the heavy chain (17). These HCAbs are shown in Figure 5.5 and have an antigen recognition part composed of single variable domains, known as the variable domain of the heavy chain of heavy-chain antibody (VHH). Nanobodies are considered the smallest intact antigen-binding fragments (molecular weight of approximately 12–15 kDa). They are robust, resistant to denaturation/thermal degradation, easy to manipulate with aqueous solubility, and capable of reducing steric hindrance and recognizing inaccessible and cryptic epitopes (18–20).
Nanobiotechnology: An Ocean of Opportunities
Published in Rajesh Singh Tomar, Anurag Jyoti, Shuchi Kaushik, Nanobiotechnology, 2020
Mala Trivedi, Rachana Singh, Parul Johri, Rajesh K. Tiwari
One primary goal in nanobiotechnology is the design of new methodologies to diagnose a number of diseases at an early stage with cheaper material and more sophisticated equipment than is possible today [48]. More research is currently being performed in this area. The utilization of metal and semiconductor NPs in biomedical applications has been demonstrated by many research groups. In 2007, Aaron et al. [78] have shown that 25-nm gold nanoparticles (AuNPs), when conjugated with anti-epidermal growth factor receptor monoclonal antibodies, can be efficiently used as in vivo targeting agents for imaging cancer markers, specifically epidermal growth factor receptors. The AuNps result in a dramatic increase in signal contrast compared to other antibody-fluorescent dye targeting agents [65]. Nanobodies have the potential to be a new generation of antibody-based therapeutics and to be used in diagnostics for diseases such as cancer. The advantages of nanobodies to developing therapeutics are the extremely stable and bind antigen with nanomolar affinity, a high target specificity, and low toxicity, the ability to combine the advantages of conventional antibodies with important features of small-molecule drugs, and their ability to be produced cost-effectively on a large scale [29]. An option for the use of antibodies in molecular biomedical is aptamers.
Receptor Binding
Published in Mihai V. Putz, New Frontiers in Nanochemistry, 2020
Corina Duda-Seiman, Daniel Duda-Seiman, Mihai V. Putz
In 1989, researchers have identified a novel type of antibodies, first in dromedaries and afterward in the species of Camelidae family. The particular aspects of these antibodies derive from the fact that they do not contain a light chain and also the lack of the first constant heavy domain. It was rapidly recognized the enlarged field of applicability of the isolated variable antigen-binding domains. Nanobodies are the smallest functional fragments of heavy chain antibodies (Vanlandschoot et al., 2011).
Effective blocking of neuropilin-1activity using oligoclonal nanobodies targeting different epitopes
Published in Preparative Biochemistry & Biotechnology, 2023
Elmira Karami, Maryam Mesbahi Moghaddam, Mahdi Behdani, Fatemeh Kazemi-Lomedasht
Angiogenesis is an important factor in the growth, development, and metastasis of tumor cells. Tumors need a complete vascular network to grow and spread.[35,39] Several factors increase angiogenesis, and NRP-1 is one of them.[3] NRP-1 is a glycoprotein and can bind to the membrane receptors.[40,41] NRP-1 is expressed in many cells, including blood vessels and neurons and highly expressed in cancer cells.[40,42] Still, many of the mechanisms that regulate NRP-1 expression are unknown. One of the identified pathways is RAS-MPK signaling. NRP-1 is transcribed by growth factors and induced by RAS-MPK signaling pathways.[43] Various substances have been used to inhibit NRP-1. Antibodies and nanobodies are inhibitors that have been studied in various studies. In one study, monoclonal antibodies that used NRP-1 and VEGFA as targets were found to reduce tumor growth.[38] Nanobodies have been used in research as a tool for cancer diagnosis and treatment.[10,15,44,45] Various nanobodies were designed against the factors involved in angiogenesis, in most of which, the designed nanobody was able to inhibit a specific factor. For example, nanobodies have been designed against EpCAM, VEGF, and NRP-1. Studies conducted at the in vitro, in vivo, and ex vivo levels have shown that these nanobodies have played an important role in inhibiting angiogenesis.[1,25,46]
Nanobodies targeting the interaction interface of programmed death receptor 1 (PD-1)/PD-1 ligand 1 (PD-1/PD-L1)
Published in Preparative Biochemistry & Biotechnology, 2020
Biyan Wen, Lin Zhao, Yuchu Wang, Chuangnan Qiu, Zhimin Xu, Kunling Huang, He Zhu, Zemin Li, Huangjin Li
Antibodies lacking the light chain exist in the peripheral blood of camels, leaving only the heavy chain variable region (VHH) and two conventional CH2 and CH3 regions.[16] The recombinant VHH shows structural stability and equivalent binding activity comparable to the original heavy chain antibody, and is the smallest unit currently known to bind the target antigen. VHH has a molecular weight of 12 ∼ 15 kDa and a disulfide bond between framework regions 1 (FR1) and FR3. Its CDR3 region is longer than that of conventional antibodies and mediates antigen recognition and binding. Its size is nanoscale (∼2.5 nm diameter × 4 nm height) and is termed a nanobody. Compared to traditional monoclonal antibodies, nanobodies have low molecular weights and display high stability, tissue penetration, and weak immunogenicity.[17] The advantages of these nanobodies make them ideal candidates for low-cost treatments, and a nanobody against PD-L1, KN035, was clinically developed by Alphamab.[18] At present, nanobodies against PD-1 or PD-L1 were usually screened with the extracellular domains of the target molecules as the antigens from the immunized alpaca-derived phage display library. However, such strategies for targeting molecular surfaces are less efficient at screening small molecule nanobody blockers. Targeting the interaction interface is an ideal strategy to block protein-protein binding. In our laboratory, a series of nanobodies targeting the dimerization of the epidermal growth factor receptor (EGFR) were obtained from a humanized nanobody phage display library using a peptide derived from the dimerization interface as the antigen, which could effectively inhibit the growth of EGFR-overexpressing tumor cells in a manner comparable to mAbs.[19,20] In this study, the feasibility of targeting interaction interface strategies for screening PD-1/PD-L1 nanobody blockers was explored by using the peptide PD-1125–136 located at the interaction interface as the antigen to screen nanobodies from a synthetic library, laying the foundation for screening the clinically valuable nanobodies from the immunized alpaca-derived phage display library.