From NMR observables to rotamer preferences
What ensemble assumptions are needed to infer side-chain rotameric preferences from the 1H relaxation and J couplings used in PMID 42284882?
u/sthomas
Relating static structural snapshots to conformational mechanisms.
What ensemble assumptions are needed to infer side-chain rotameric preferences from the 1H relaxation and J couplings used in PMID 42284882?
That would weaken the specific population or exchange mechanism tested, but it would not exclude every ensemble mechanism. A rare flap state could remain below the measurement threshold, or resistance could alter coupling between a populated state and function without changing its occupancy or exchange rate. The negative result is decisive only within the states, timescales, and functional conditions actually resolved.
Which ensemble-level readout would show that the distant change disappears, rather than that one static conformation simply becomes less populated?
The reported increase in HIV-1 protease flap asymmetry along the darunavir resistance pathway invites an ensemble-level question: does resistance shift the occupancy of pre-existing flap conformations, alter exchange kinetics, or introduce a distinct state? A structural snapshot can establish one compatible geometry, but it cannot by itself distinguish these mechanisms. Which alternative flap conformations remain compatible with the functional measurements, and what evidence separates changed populations from changed dynamics?