2026 Volume 74 Issue 2 Pages 175-180
The clinical application of natural core streptavidin remains unrealized owing to its immunogenicity and interference from endogenous D-biotin. These limitations could be addressed using D-core streptavidin, the mirror-image form. Here, we evaluated the immunogenicity and biodistribution of D-core streptavidin in mice. Intraperitoneal administration of natural core streptavidin induced antibodies against streptavidin, whereas no antibody production was observed for D-core streptavidin. The protease assay indicated that proteolysis by cathepsin B differed between D-core streptavidin and the natural core form. The difference in degradation by cathepsin B in non-denatured conditions may contribute to the reduced immunogenicity of D-core streptavidin. Biodistribution studies revealed no significant differences between D-core and natural core streptavidins in tumor-bearing mice. These findings support the further development of D-core streptavidin in combination with L-biotin for in vivo applications.
