Professor George Lorimer FRS
George Lorimer is recognized for his insightful work on mechanism of two proteins, Rubisco and the GroE chaperonins. Rubisco is the enzyme responsible for the photosynthetic fixation of CO2, and the GroE chaperonins enable the ATP-dependent folding of many other proteins.
Using 18O2 George demonstrated the oxygenase activity of Rubisco, both in vivo and in vitro. He further established the novel mechanism for the activation of Rubisco by CO2, the formation of a lysyl-carbamate in the active site. With his colleagues at DuPont he employed chemical quench and other techniques to trap and identify the 6-carbon reaction intermediate of the carboxylation reaction and defined the complete stereo-chemical course of the reaction.
In 1889, using an unequivocally unfolded protein and the purified chaperonin proteins GroEL and GroES, his group was the first to demonstrate the ATP- dependent folding of Rubisco and many other proteins. With Thirumalai he performed a bio-informatic analysis to define the structural elements of the substrate proteins that GroEL recognizes. George has also shown that GroEL can perform work on substrate protein during allosteric transitions. He has determined the crystal structure of the functional form, the symmetric GroEL:GroES2 “football” and established that the GroEL rings operate as parallel-processing, iterative annealing machines.
George is also a member of the National Academy of Sciences.
Interests and expertise