Enzyme-catalyzed reactions, temporal

The bacteriophage T4 is a complex virus capable of infecting certain bacteria. The virus protein coat (head, tail and tail fibers) contains 40 structural proteins. T4 illustrates well the spatial and temporal control of the stepwise assembly process and the role of external input in regulating that process. A further 13 proteins are required for assembly but do not appear in the completed virus particle. Three of these act as a transient template to promote the formation of the tail baseplate (Fig. 5-3). Another one is a protease which cleaves the major protein of the head (from 55 kDa to 45 kDa) but only after the head has been partially assembled. It is only when the tail reaches its correct length that the cap protein is placed on top allowing the completed head to become attached (Fig. 5-3). Finally, the intact tail fibers are added at the baseplate, and this requires an enzyme-catalyzed reaction to occur. 

FIGURE 1.14 The first two rows show the normal absorptions for substrate (continuous curves) and product (dashed curves) concentrations of the enzyme-catalyzed reaction without inhibition, based on the logistical temporal approximation, and on the IF-Lambert temporal solution, respectively the third row depicts the difieience between IF-Lambert and logistical counterpart for substrate or product normal absorption progress curves on the columns, the plots are presented for the enzyme/substrate ratio e taking the in vitro and almost the in vivo values, from 10" to 10 and equal or greater than 10, respectively the employed kinetic parameters are the maximum velocity of enzyme reaction 1 O Mxsr and the Michaelis... 

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