Achieving robust attachment between living tissues and inert materials faces the challenge of mitigating contact damage due to mismatches in critical properties such as stiffness, hardness, strength and Poisson’s ratio. The byssal threads of the fan shell Atrina pectinata are non-living stiff materials intimately associated with soft living tissue, which provide an intriguing paradigm of bionic interface for mitigating contact damage. Interfacial load-bearing protein (A. pectinata foot proteins) with L-3,4-dihydroxyphenylalanine (DOPA)-containing and sugar-binding domains (lectins) have been characterized from the interface between Atrina foot and the byssal threads. The interfacial proteins were localized at the interface between stiff byssus and the soft tissue by immunochemical staining and confocal Raman imaging, implying that the interfacial proteins are the interfacial linkers between the byssus and soft tissue, that is, the DOPA-containing domains and lectins interact with itself, other byssal proteins, and mucus layers at the interface. Since both DOPA- and lectin-mediated binding are strong and reversible wet conditions, these bindings are likely to act as sacrificial bindings for mitigating the contact damages. This result suggests the combination of catechol and lectin chemistry at the mechanically mismatched interfaces is applicable to bionic interface design for tissue engineering.