Conclusions

• H/D exchange can be followed in several proteins, including AP, LADH, and G6PDH by measuring the tryptophan RTP lifetime as a function of time.



• The RTP lifetime does have an inverse correlation to H/D exchange rates for native AP, LADH, and G6PDH.



• The extremely rapid H/D exchange observed in Zn bound AP clearly shows the problems with interpreting the RTP lifetime as a simple reporter of ëëlocal viscosityíí.



• The short RTP lifetime and rapid H/D exchange of apo AP correlates well with what is known about its stability relative to holo AP.



• The RTP lifetime can report on the conformational changes that occur near the AP active site when the protein binds various ammounts of zinc, magnesium, and phosphate.

References