Regeneration of Visual Pigments from their Low-temperature Photoproducts

Abstract

Hubbard and Kropf's explanation of my results is based on the statement that the experiments were “performed in circumstances in which photochemical and thermal processes take place side by side”. The implication here is that irradiation converted the parent visual pigment to an orange photoproduct, and that this photoproduct was unstable and decayed to indicator yellow. This is not so. It was explicitly stated that the orange photoproduct produced by irradiating frog rhodopsin at − 5° C. was thermally stable.