38 



VIRUSES 



The unprecedented behavior of tobacco mosaic virus can be explained on 

 the basis of a few simple and plausible assumptions. 



283 293 303 

 TEMP. - °A 



323 



-1 



PIGITRE 30 - SPECIFIC REACJTION VELOCITY IN L'lN. "^ OF UREA 

 DENATUBATIOH OF TOBACCO MOSAIC VIRUS PLOTTED AS A FUNCTION 

 OF ABSOLUTE TEITPERATURE . (li»A. Lauffer, J. Amer. Ohem . Soc , 

 65, 1793 (1943) ). 



The curve in Figure 30 could be visualized as being made up o 

 curves, one of which decreases from a high value and approach 

 tically as temperature is increased towards room temperature, 

 which does the same thing as temperature is decreased towards 

 iiach of these curves could represent a separate denaturation 

 a negative temperature coefficient and one with a positive co 

 therefore, make the assumption that tobacco mosaic virus in u 

 natured by at least two simultaneous parallel routes or proce 

 ble to conceive of an urea denaturation process with a negati 

 temperature coefficient, if it is assumed that the urea must 

 with the virus to form an urea-virus compound, 'rhich then can 

 to the usual laws, if this mechanism is right, the rate of c 

 virus to denatured virus by this process must depend at all t 

 (1) the specific rate for disintegration of the complex and ( 

 the total undenatured virus in the combined state. These ide 

 ed by the following equation; j^t jji 1 j^ . 



xU + 1 /-— * V U X — > V* , nD 



f the sun of two 

 es zero assympto- 

 and the otner of 

 room temperature. 

 process, one with 

 efficient, iiet us, 

 rea can be de- 

 sses . it is possi- 

 ve differential 

 react reversibly 



denature according 

 hange of native 

 imes upon two things » 

 2) the fraction of 

 as can be represent- 



ll4j 



