THE MODULATION OF ENZYME REACTION-RATES WITHIN MULTIENZYME COMPLEXES .1. STATISTICAL THERMODYNAMICS OF INFORMATION-TRANSFER THROUGH MULTIENZYME COMPLEXES
J. Ricard et al., THE MODULATION OF ENZYME REACTION-RATES WITHIN MULTIENZYME COMPLEXES .1. STATISTICAL THERMODYNAMICS OF INFORMATION-TRANSFER THROUGH MULTIENZYME COMPLEXES, European journal of biochemistry, 226(3), 1994, pp. 993-998
There is now experimental evidence that association of different enzym
es as a multi-enzyme complex may result in an alteration of the cataly
tic properties of the enzymes present in this complex. This effect is
not related to the channelling of reaction intermediates between diffe
rent active sites. It appears as a consequence of an information trans
fer that occurs within the multi-enzyme complex. A theory, based on st
atistical thermodynamics, has been developed which provides an underst
anding, on a physical basis, for how isologous as well as heterologous
interactions between identical, or different, enzymes of the complex
may modulate the catalytic properties of an oligomeric enzyme of that
complex. The theory predicts three possible types of effects: an alter
ation, through heterologous interactions, of an already existing co-op
erativity of the oligomeric enzyme within the complex; a co-operativit
y, generated by heterologous interactions in the complex that could no
t occur if the oligomeric enzyme were isolated from the rest of the co
mplex; a Michaelis-Menten character of the oligomeric enzyme within th
e complex, but with altered values of V-m and K-m relative to what wou
ld have been observed with the naked enzyme. All these effects appear
as a consequence of a transfer of information between different enzyme
s of the same multi-protein complex. The following paper in this journ
al shows how one can demonstrate and characterize experimentally these
effects in a multi-enzyme complex containing ribulose bisphosphate ca
rboxylase-oxygenase.