Synthetic studies on the extracellular domain of the T cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain (TIGIT) using Trt-K10 solubilizing tags

• Published in: Bioorganic & medicinal chemistry Vol. 99; p. 117585
• Main Authors: Iwamoto, Naoya, Sasaki, Jumpei, Ohno, Saya, Aoki, Keisuke, Usui, Yusuke, Inuki, Shinsuke, Ohno, Hiroaki, Oishi, Shinya
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2024
• Subjects: CD155; Chemical protein synthesis; Solubilizing tag; T cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain; TIGIT; Solubilizing tag; MeNbz; Chemical protein synthesis; BISIAL; T cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain; SPPS; ITT; PVR; TFA; SPR; IgV; CTLA-4; TIGIT; RBM; Dbz; CD155; PBS; PD-1/PD-L1; MPAA; Thz; VA-044; EDTA; ITIM; scFv; HEPES; NCL; TCEP; TIS
• ISSN: 0968-0896; 1464-3391
• DOI: 10.1016/j.bmc.2023.117585

[Display omitted] The T cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain (TIGIT) is an inhibitory immunoreceptor expressed on lymphocytes that serves as a promising target for cancer immunotherapy. In this study, facile synthetic protocols to produce the extracellular domain of TIGIT were investigated for applications of TIGIT in mirror-image screening. During the synthesis via sequential native chemical ligations, we encountered problems with significantly poor solubility of the ligated products. Introducing trityl-type solubilizing auxiliaries, which also functioned as temporary protecting groups for cysteine residues, facilitated a flexible order of ligations and efficient purification protocols. After refolding under appropriate conditions, the synthetic TIGIT showed a sufficient affinity toward its target ligand CD155.