In 1943, with the help of Arda Green, the pair illustrated that glycogen phosphorylase existed in either the a or b forms depending on its phosphorylation state, as well as in the R or T states based on the presences of AMP.
En 1943, coa axuda de Arda Green, determinaron que a glicóxeno fosforilase existía en dúas formas, a e b, dependendo do seu estado de fosforilación, e nos estados R ou T baseándose na presenza de AMP.