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Indole Inhibition of Cofactor Activated Bacteriophage


McKee, John William (1955) Indole Inhibition of Cofactor Activated Bacteriophage. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/ZGNP-5Q24.


Certain bacteriophage strains must be activated by a cofactor before attachment to their host cells is possible. In some of these strains indole competitively inhibits the activation. This inhibition by indole is the subject of the present study. The following sets of measurements were made: 1) Kinetics of the approach to equilibrium from both sides. 2) Deactivation in the presence of indole. 3) Activation in cofactor after pre-equilibration with indole. 4) Measurements of the equilibrium activity in the presence of various cofactor-indole mixtures. The following principal conclusions may be drawn: 1) A true thermodynamic equilibrium exists between indole-deactivated virus and active virus. 2) The presence of indole increases the rate of deactivation of the virus population in the absence of external cofactor, over that found when only cofactor is removed. 3) Indole combines only with active phage particles. 4) At equilibrium in the presence of high concentrations of cofactor and in the range of strong inhibition, the activity is inversely proportional to the concentration of indole. These findings make it necessary to modify the theory of activation previously developed by Stent and Wollman. It is assumed that the surface of the phage particle, during the process of activation, undergoes a structural change perhaps similar to the reversible denaturation of proteins.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:(Physics and Biology)
Degree Grantor:California Institute of Technology
Division:Physics, Mathematics and Astronomy
Major Option:Physics
Minor Option:Biology
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Delbruck, Max
Thesis Committee:
  • Unknown, Unknown
Defense Date:1 January 1955
Record Number:CaltechETD:etd-01152004-114246
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:186
Deposited By: Imported from ETD-db
Deposited On:16 Jan 2004
Last Modified:06 Jul 2023 18:23

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PDF (McKee_jw_1955.pdf) - Final Version
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