Biology subjects

Shin, H.-C.

Publications and source records attributed to Shin, H.-C..

3 recordsLinked to original sources

bioRxiv2026

Rational Redesign of an Fc-Binding Peptide for Multivalent Antibody Assembly

Multivalent antibody assemblies offer opportunities to enhance avidity, organize immune complexes, and modulate higher-order protein interactions, but constructing such architectures from existing immunoglobulin G (IgG) molecules without redesigning the antibody scaffold remains challenging. Here, we report the rational redesign of a Protein A-derived Fc-binding peptide into ADP1, a stable dimeric Fc-binding peptide that directs Fc-mediated antibody assembly. ADP1 was designed from the parent Fc-binding peptide Z34C by preserving the Fc-recognition surface while redesigning the opposite helical surface to promote peptide-peptide association. Biophysical characterization showed that ADP1 retained nanomolar Fc-binding affinity while exhibiting markedly enhanced chemical and proteolytic stability compared with the parent peptide. Structural analyses of ADP1-Fc complexes revealed that ADP1 bridges neighboring Fc regions through a combined ADP1-Fc and ADP1-ADP1 interface, generating spiral higher-order Fc assemblies. This assembly principle was further extended to full-length IgG, where ADP1 promoted higher-order antibody association in a concentration-sensitive manner. In addition, covalent ADP1 functionalization enabled Fc-directed modification of full-length IgG while retaining Fab-mediated antigen recognition, demonstrating the utility of ADP1 as an antibody assembly and functionalization module. Finally, competitive addition of the parent Z34C peptide modulated ADP1-driven antibody assembly, suggesting a potential route for tuning Fc-mediated assembly propagation. Together, this work establishes a redesigned Fc-binding peptide platform for directing multivalent antibody assembly and functionalization without genetic reengineering of the IgG scaffold. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=177 SRC="FIGDIR/small/737354v2_ufig1.gif" ALT="Figure 1"> View larger version (42K): org.highwire.dtl.DTLVardef@57cadeorg.highwire.dtl.DTLVardef@1c7d8e6org.highwire.dtl.DTLVardef@170fb85org.highwire.dtl.DTLVardef@90e6d6_HPS_FORMAT_FIGEXP M_FIG C_FIG

biochemistry↗

bioRxiv2026

De novo design of a safe and potent respiratory syncytial virus immuno-focusing antigen

Respiratory syncytial virus (RSV) remains the leading cause of severe respiratory infections in infants, the elderly, and the immunocompromised. Although stabilized full-length pre-fusion (pre-F) protein vaccines are promising, enhanced respiratory disease (ERD) remains a critical safety concern. Here, we used artificial intelligence to design a de novo immuno-focused antigen that structurally preserves the RSV F head region containing critical neutralising epitopes-- site O, II and V-while replacing the non-neutralising stem with a computationally designed scaffold to minimise immunopathological risk. The lead candidate, aRF6, elicited robust protective immunity against RSV in mice and similar immunogenicity in non-human primates without detectable toxicity. Importantly, in stringent ERD-promoting models, aRF6 induced minimal pulmonary pathology and markedly attenuated Th2-biased cytokine responses, outperforming formalin-inactivated RSV and full-length-stabilized pre-F. The results of cryoelectron microscopy confirmed that the aRF6 structure precisely matched the computational predictions. These results demonstrated that computationally designed de novo immuno-focused antigens can yield safe and effective RSV vaccines, thereby providing a rational framework for next-generation vaccine development.

microbiology↗

bioRxiv2025

De Novo design of a potent Wnt Surrogate specific for the frizzled7 subtype members

In humans, 19 Wnt ligands interact with 10 Frizzled (Fzd) receptors and the co-receptors LRP5/6 to initiate signaling. Wnts and Fzds are highly promiscuous, making it challenging to dissect the specific outcomes of individual Wnt-Fzd interactions. Developing Wnt surrogates with specificity for individual Fzd subtypes could be pivotal. We present a modular, potent, and Fzd7-specific Wnt surrogate that consists of three de novo designed modules, a Fzd7 binder, an LRP6 binder and a homodimeric protein. The Fzd7-specific module was designed by targeting two less conserved surface patches on the cysteine-rich domain (CRD) of Fzds to achieve both selectivity and affinity. It exhibits a strong binding affinity (KD < 2.3 nM) for the very closely related Fzd7 subtype members (Fzd7, Fzd1, Fzd2) with no measurable binding to the CRDs of the other seven Fzd receptors. This Wnt surrogate induced spheroid organoid formation from intestinal stem cells at subnanomolar concentration, and promoted full hair follicle regeneration and robust hair growth in mice. These results suggest that our strategy could be extended to design modular Wnt surrogates capable of selectively activating individual Fzd receptors, providing a valuable tool kit for development and differentiation, organoid cultures and targeted regeneration.

bioengineering↗