Dear Chandradeep,

A few years ago we were involved in the study using temperature derivative spectroscopy (TDS) with FTIR monitoring to explore the dynamics of NO and carbon monoxide (CO) inside iNOS after photodissociation at cryogenic temperatures. Only a single kinetic photoproduct state was revealed, but no secondary docking sites as in hemoglobins. We observed that intense illumination of six-coordinate ferrous iNOSoxy-NO ruptures the bond between the heme iron and the proximal thiolate TO YIELD five-coordinate ferric iNOSoxy-NO, demonstrating the strong trans effect of the heme-bound NO.

Best wishes,

Ilya