SINGLE- OR DUAL-MODE SWITCHING OF SEMISYNTHETIC RIBONUCLEASE S' WITH AN IMINODIACETIC ACID MOIETY IN RESPONSE TO THE COPPER(II) CONCENTRATION

Ribonuclease S′ bearing iminodiacetic acid as a metal-bindingsite was designed and semisynthesized by self-assembly of native S-protein with chemically modified S-peptide. Rationally designed incorporation of unnatural iminodiacetic acid groups as transition metal receptors can confer the dual mode of response to a metal cation (stabilization/destabilization, and thus activation/deactivation) with regard to the structure and activity of an enzyme (see diagram).