Herbert ‘Freddie’ Gutfreund’s early work on the molecular weights of proteins, the reversible association of insulin and of the subunits of haemoglobin made a significant contribution to a difficult subject.
His principal achievements came from developing rapid reaction techniques to identify and characterise elementary steps in enzyme catalysed reactions. In his studies of proteolytic enzymes, alkaline phosphatase and NAD linked dehydrogenases he was first to obtain direct estimates of the rate of substrate combination and the rate of hydrogen transfer from substrate to coenzyme in the catalytic step of dehydrogenase reactions. He obtained kinetic evidence that conformational changes of these enzymes occur as distinct steps in the mechanisms. Freddie and collaborators also studied the kinetics of proton release in the alcohol and lactate dehydrogenase reactions, contributing substantially to our understanding of these mechanisms. The observations of equilibria between enzyme-substrate and enzyme-product complexes and the rate limit of product release are of general importance in the post Michaelis-Menten view of enzyme mechanisms.
The techniques developed were seminal in applications to other processes in molecular physiology such as muscle contraction and ion transport. The research group set up by Freddie in Bristol is widely recognised as a productive centre for the application of rapid reaction techniques to many of these problems. In the last 30 years several groups with similar interests have been organised by alumni of Freddie’s laboratory in England and abroad.
Professor Herbert Gutfreund FRS died on 21 March 2021.
