Compare alternatives by the job they need to do
Covalent-site profiling can identify ligandable residues, while allosteric tools map structural influence. BioTwin’s target-specific composite connects those questions: alternative cysteines, modeled communication, ensemble geometry, linker reach and possible non-cysteine chemistry are assessed against a stated functional objective.
Turn an inaccessible site into a testable route
A proposed sequence is to nominate an allosteric perturbation, look for another chemical handle with relevant modeled coupling, and examine whether a tether can place the reacting group productively. Boltzmann ensemble assessment and fit/access can then challenge the structural assumptions. The target-specific work includes explored and rejected routes; it does not show that all such substitutions work.
Similar coupling is a hypothesis about function
A nearby or similarly coupled site may produce a different biological response. Residue identity, construct differences, reaction geometry and selectivity must travel with the proposal. The decisive comparison is an intervention at each candidate site with a direct functional readout. That result determines whether the alternative preserves the mechanism the program actually needs.